Restore CRLF line endings in ManagesBalance

Release 3.3.0

CHANGELOG.md

@@ -0,0 +1,74 @@
+# Changelog
+
+## Unreleased
+
+Preferences, charges and the billing limit; they need an Anikeen ID release that supports them.
+
+### Added
+
+- Preferences of any user with the app's token (trusted apps, registered by Anikeen per
+  namespace): `preferencesByUserId()`, `preferenceByUserId()`, `setPreferenceByUserId()`,
+  `deletePreferenceByUserId()` and `findUserIdByPreference()` (the user holding a value of a unique
+  key, `null` when nobody does).
+- The user's shared preferences with their token: `globalPreferences()`, `globalPreference()`,
+  `setGlobalPreference()` and `deleteGlobalPreference()` on `Billable`, cached per instance.
+- `Resources\Preference` and `Resources\Preferences`; `Enums\SharedPreference` and
+  `Enums\Appearance`.
+- Conditional writes: `ifVersion` (`If-Match`) and `createOnly` (`If-None-Match: *`);
+  `PreconditionFailedException` (a subclass of `ApiException`) for 412 with `currentVersion()`.
+- Scopes `Scope::PREFERENCES`, `PREFERENCES_READ` and `PREFERENCES_CLIENT`.
+- Webhook event `order.refunded` (`EventType::ORDER_REFUNDED`).
+- Charges on a user's monthly bill for trusted apps: `createChargeForUser()` (with an idempotency
+  key), `findChargeForUser()` and `voidChargeForUser()`; `Resources\AppCharge`.
+- The user's billing limit for trusted apps: `billingLimitForUser()` and `Resources\BillingLimit`
+  (`allows()` is advisory); the `billing_limit` key of `billingOverview()` is documented.
+- `ApiException::isBillingLimitReached()` for 409 `billing_limit_reached`.
+- Opt-in webhook events `billing_limit.reached` and `billing_limit.available`
+  (`EventType::BILLING_LIMIT_REACHED`, `BILLING_LIMIT_AVAILABLE`).
+- An optional trailing `$headers` argument on `AnikeenId::request()`, `get()`, `post()`, `put()`,
+  `delete()` and `AppRequest::send()`; calls without it send the same request as before.
+
+## 3.3.0 (2026-11-06)
+
+App billing features; they need an Anikeen ID release that supports them.
+
+- Free trials: `trial_days` / `trial_ends_at` (optional `trial_once`, `trial_payment_method` with
+  `TrialPaymentMethod::REQUIRED` / `OPTIONAL`) when creating subscriptions and checkout sessions;
+  `Subscription::isTrial()`.
+- Discounts per billed period: `discount` with `percent_off` or `amount_off`, `duration` and `label`.
+- Plan changes of running subscriptions: `AppSubscription::change()` (`apply: now` or
+  `period_end`) and `AppSubscription::cancelScheduledChange()`.
+- App orders: order lines with subscription, period, net amount and discount;
+  `AppOrders::invoicePdf()`. Confirmable orders of trusted apps (`confirm: true`).
+- Billing portal links that work without a login: `createBillingPortalLinkForUser()` and
+  `appBillingPortalUrl()`.
+- Webhook events `subscription.trial_will_end`, `subscription.discount_ended`,
+  `subscription.updated` and `subscription.renewed` (`EventType::SUBSCRIPTION_*`);
+  `data.reason` with `CancellationReason::TRIAL_ENDED_WITHOUT_PAYMENT_METHOD`.
+
+## 3.2.0 (2026-11-06)
+
+Elapsed-period billing and user lookup; they need an Anikeen ID release that supports them.
+
+- `AppSubscription::checkout()` takes `billElapsedPeriods` and `maxNetAmount`: a subscription
+  started more than one period ago is billed for its elapsed periods too, up to the given net
+  amount (409 `elapsed_amount_exceeded` with `net_amount`, `elapsed_periods_not_allowed`). Calls
+  without the new arguments send the same request as before.
+- `ApiException::body()` returns the JSON body of Anikeen ID's error response, e.g. its
+  `net_amount`.
+- Add `AnikeenId::findUserByEmail()` for trusted apps: looks up an account by email address
+  (regardless of case) without creating one, null when there is none.
+- `createUser()` documents `name`, `password_confirmation` and `send_invitation` (a newly created
+  account gets an invitation mail to set a password) and the response fields `created` and
+  `invitation_sent`.
+
+## 3.1.0 (2026-11-05)
+
+- Add the scope `products:read` (`Scope::PRODUCTS_READ`) for read-only access to the product APIs
+  of the Anikeen Console.
+- Add the reseller scopes `reseller-customers:read`, `reseller-customers`, `reseller-grants` and
+  `reseller-orders` (`Scope::RESELLER_CUSTOMERS_READ`, `Scope::RESELLER_CUSTOMERS`,
+  `Scope::RESELLER_GRANTS`, `Scope::RESELLER_ORDERS`) for the reseller API of the Anikeen Console.
+- Document the scope schema and the new scopes in the README.
+
+Older releases: see the [GitHub releases](https://github.com/anikeen-com/id/releases) and tags.

CLAUDE.md

@@ -0,0 +1,64 @@
+# CLAUDE.md
+
+Guidance for Claude Code (and other contributors) working in this repository.
+
+## What this is
+
+`anikeen/id` is the public PHP client for the Anikeen ID API, shipped as a Laravel package
+(Laravel 11–13, PHP 8.2+). It covers OAuth/Socialite login, an API token guard, and the billing
+API (subscriptions, orders, checkout sessions, shipments, invoices, webhooks). This is a public
+repo published on Packagist: never commit secrets, internal hostnames or customer data.
+
+## Commands
+
+```shell
+composer install
+composer test                                   # vendor/bin/phpunit
+vendor/bin/phpunit --filter AppSubscriptionsTest
+composer docs                                   # regenerate README.md from README.stub
+```
+
+CI (`.github/workflows/tests.yml`) runs PHPUnit on PHP 8.3 and 8.4.
+
+## Layout
+
+- `src/Id/AnikeenId.php` – the API client (singleton, facade `AnikeenId`). Reads
+  `config('services.anikeen.*')`; `mode=staging` switches to the staging base URL unless
+  `base_url` is set. `request()` wraps Guzzle and returns a `Result`.
+- `src/Id/Billable.php` – trait for the app's user model; composes the `Concerns/Manages*` traits.
+  Its API caches are declared properties on purpose (undeclared ones would be treated as Eloquent
+  attributes and break `save()`). Add a new cache property there when a concern caches.
+- `src/Id/Concerns/` – one trait per API area. Traits on `AnikeenId` act as the app/client;
+  traits on `Billable` act for one user.
+- `src/Id/Resources/` – `BaseResource` (single object) and `BaseCollection` (lists, built via
+  `::builder()`). Failed requests throw `ApiException::fromResult()` (`CollectionException` for
+  lists), no response `::unreachable()`, `confirmation_required` a `ConfirmationRequiredException`.
+  All extend `ResourceException`.
+- `src/Id/Resources/App*` – "app" variants that use the app's own client-credentials token
+  (`AnikeenId::asApp()`, `Support/AppRequest`) instead of the user's token, for trusted apps.
+  They must not send any request until a method is called.
+- `src/Id/Auth/`, `Providers/AnikeenIdServiceProvider.php`, `Http/Middleware/` – the `anikeen`
+  guard driver and user provider, JWT validation (`Helpers/JwtParser.php` with the bundled
+  `oauth-public*.key`), scope middleware.
+- `src/Id/Webhooks/` – signature verification (`Webhook::constructEvent`) and `EventType`
+  constants.
+- `src/Support/Query.php` – query-string builder.
+- `generator/generate-docs.php` – reflects the public methods of `AnikeenId` and `Billable` traits
+  into the README.
+
+## Conventions
+
+- **README:** edit `README.stub`, never `README.md` directly, then run `composer docs`. The
+  `<!-- GENERATED-DOCS -->` marker is replaced with the method reference. Commit both files.
+- **New endpoints:** add a method to the matching `Concerns/Manages*` trait (or a resource class),
+  document request attributes with an `array{…}` PHPDoc shape and a short description per key,
+  and add an example to `README.stub` when it is a new feature.
+- **Tests:** extend `Anikeen\Id\Tests\TestCase` (Orchestra Testbench). No live API: queue
+  responses with `$this->respond($status, $body)` (Guzzle `MockHandler`) and assert the sent
+  requests via `$this->sent` / `$this->sentJson($i)` – method, path, `Authorization` header and
+  JSON body. The app token is faked as `app-token`.
+- **Compatibility:** this is a library used by several apps. Keep public method signatures
+  backwards compatible; add optional parameters instead of changing existing ones.
+- Code, comments, docs and commit messages in English. Commit subjects are short, imperative,
+  sentence case (e.g. "Ship orders: shipments with delivery notes"). Work happens on feature
+  branches merged via PR into `main`.

composer.json

@@ -15,15 +15,15 @@
   "require": {
     "php": "^8.2",
     "ext-json": "*",
-    "illuminate/support": "^11.0|^12.0|^13.0",
+    "illuminate/support": "^12.69|^13.0",
-    "illuminate/console": "^11.0|^12.0|^13.0",
+    "illuminate/console": "^12.69|^13.0",
     "guzzlehttp/guzzle": "^7.8",
     "socialiteproviders/manager": "^4.6",
-    "firebase/php-jwt": "^6.10|^7.0"
+    "firebase/php-jwt": "^7.0"
   },
   "require-dev": {
-    "laravel/framework": "^11.0|^12.0|^13.0",
+    "laravel/framework": "^12.69|^13.0",
-    "orchestra/testbench": "^9.0|^10.0|^11.0",
+    "orchestra/testbench": "^10.0|^11.0",
     "phpunit/phpunit": "^11.0|^12.0"
   },
   "autoload": {

oauth-public.staging.key

@@ -1,14 +1,14 @@
------BEGIN PUBLIC KEY-----
+-----BEGIN PUBLIC KEY-----
-MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAi4Ta8r01zKaGSnGi1EiD
+MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEArGn4rtfKjlLtJsh61eW/
-uMFWRXBlK4y/ZIfWBpElmS2ygv4mGeP3hT4Flm696Z2UMy56KC+c7CC/PQCiutLk
+cZdLC6ECbSUKVTZlLLvRoYr7Li6RKRDiIj7KEy+lRL4miiMtadXNx6d89KZwr8SL
-5NUphyX/t+0QS5Dqpw6FB33fLTNNY7GqSmGIUE4os8XYZRSyDQRgtOgq3R3vJkoV
+DQXDbP//F3HEXVJBtr6j8p8HbJh1pinLJeKtcmeJfOIwVLyQ3sPdewkQoFtwkQyF
-7zoavTJmSCQlG5Qf0T//iMmzQ+b+6VZm1CJSz5nGx94u1DuXNyP5Epkk0wuHrtwy
+uZWLeh6TCfAtcQs49I6C0rYgLDQrfTzvQ195mX1HkgArndNDXBiECMYCCulmPpzv
-kADR2lmydNodJzqpSD+8yQqnAhOZNtNF4qwQ3g13fRvHycBp3G2nlCfOn2g5PmYD
+yq5MWS5+/uQjKmPToo5lPfKxbWD6lyLII9ZkGp7wFilSonpUN1LmwRJlgQqh+1Hb
-KYBKqvTq4PQH4E+K3pbbMz6zf/T6Dw7zTfksqHR4hqMgN6byRRxmwuBczIumcu9b
+celGHTIXiP3lDNIG3sR/H5v6vwGeqfu9MBQ2Ksrz259O1aojqRQ+d9k1dj8pcbuC
-y7xbgoIGIVZXgJliALPFi+zTPTN7c8MedFs/xCBHCmzWYTCZfHgr8RPRewD19tCG
+ZurlI4++JOsmecc4B3g8tvlsevlb0UbtW/JHKckgK/JL9PO+04WJD+hSJrEhokLq
-NSny5R0vlArpuZCTTgedPESDeGU4eNEddg4yXFzKlpE2nNuvzZ1Ohruc5ETOSU19
+aB5Ceg6FKwqoM0l7dtoHRka8vh/q/UU3oawUESoZ5l3TjWI4b0jZzsJqE4cyKgK3
-RTCBUBkjeL6ESZRd/yKGjbVx4dEYxZdIz4yBl+hZ2ZOIyG7L3zPrccAWrPpG56xr
+S3tBooj4rM4dOh4y7crD1PcsJG/IF2bg4YEAO8q8Fz6TmOzCM20oBhaLrFJOnYph
-E5IDBXxLFhaJ5LlyEAGQehB0ShEuCdkr88Xz7ba9PHpGqY83l4//ULrqPIZPAa4Z
+Xhhl7ZPHqCCIt6HSDbwlFJw1Iw/2nygnkAZ0iJV/EQl0M+zlDGEv41SWHQfsLTK6
-E3AWHT1ZtXNPeA4SzZ9Y9Oij4M3chyHxqM0lL3kYP+dstZehTujStfElDIx2Ni10
+HBSM1QSEbuMz0sF/TpolYEvYso+nCDjDzQ4MFdhGxH6OVyuSySm6nG0fK/Bio5Ow
-73tILu4edYS0FxsL19m8gbsCAwEAAQ==
+6SNz0wIg3RagjzTbljHsT4cCAwEAAQ==
------END PUBLIC KEY-----
+-----END PUBLIC KEY-----

src/Id/AnikeenId.php

@@ -2,6 +2,7 @@
 
 namespace Anikeen\Id;
 
+use Anikeen\Id\Concerns\ManagesPreferences;
 use Anikeen\Id\Concerns\ManagesPricing;
 use Anikeen\Id\Concerns\ManagesProducts;
 use Anikeen\Id\Concerns\ManagesShippingLabels;
@@ -23,6 +24,7 @@ use Illuminate\Contracts\Auth\Authenticatable;
 class AnikeenId
 {
     use OauthTrait;
+    use ManagesPreferences;
     use ManagesPricing;
     use ManagesProducts;
     use ManagesShippingLabels;
@@ -369,10 +371,12 @@ class AnikeenId
     /**
      * Build query & execute.
      *
+     * @param array<string, string> $headers Extra request headers, e.g. `If-Match` for conditional
+     *     writes; they are sent in addition to (and may not replace) Client-ID, Accept and Authorization.
      * @throws GuzzleException
      * @throws RequestRequiresClientIdException
      */
-    public function request(string $method, string $path, null|array $payload = null, array $parameters = [], ?Paginator $paginator = null, bool $useClientSecret = false): Result
+    public function request(string $method, string $path, null|array $payload = null, array $parameters = [], ?Paginator $paginator = null, bool $useClientSecret = false, array $headers = []): Result
     {
         if ($paginator !== null) {
             $parameters[$paginator->action] = $paginator->cursor();
@@ -380,7 +384,7 @@ class AnikeenId
 
         try {
             $response = $this->client->request($method, $path, [
-                'headers' => $this->buildHeaders((bool)$payload, $useClientSecret),
+                'headers' => $this->buildHeaders((bool)$payload, $useClientSecret) + $headers,
                 'query' => Query::build($parameters),
                 'json' => $payload ?: null,
             ]);
@@ -419,35 +423,35 @@ class AnikeenId
      * @throws GuzzleException
      * @throws RequestRequiresClientIdException
      */
-    public function get(string $path, array $parameters = [], ?Paginator $paginator = null): Result
+    public function get(string $path, array $parameters = [], ?Paginator $paginator = null, array $headers = []): Result
     {
-        return $this->request('GET', $path, null, $parameters, $paginator);
+        return $this->request('GET', $path, null, $parameters, $paginator, false, $headers);
     }
 
     /**
      * @throws GuzzleException
      * @throws RequestRequiresClientIdException
      */
-    public function post(string $path, array $payload = [], array $parameters = [], ?Paginator $paginator = null): Result
+    public function post(string $path, array $payload = [], array $parameters = [], ?Paginator $paginator = null, array $headers = []): Result
     {
-        return $this->request('POST', $path, $payload, $parameters, $paginator);
+        return $this->request('POST', $path, $payload, $parameters, $paginator, false, $headers);
     }
 
     /**
      * @throws GuzzleException
      * @throws RequestRequiresClientIdException
      */
-    public function put(string $path, array $payload = [], array $parameters = [], ?Paginator $paginator = null): Result
+    public function put(string $path, array $payload = [], array $parameters = [], ?Paginator $paginator = null, array $headers = []): Result
     {
-        return $this->request('PUT', $path, $payload, $parameters, $paginator);
+        return $this->request('PUT', $path, $payload, $parameters, $paginator, false, $headers);
     }
 
     /**
      * @throws GuzzleException
      * @throws RequestRequiresClientIdException
      */
-    public function delete(string $path, array $payload = [], array $parameters = [], ?Paginator $paginator = null): Result
+    public function delete(string $path, array $payload = [], array $parameters = [], ?Paginator $paginator = null, array $headers = []): Result
     {
-        return $this->request('DELETE', $path, $payload, $parameters, $paginator);
+        return $this->request('DELETE', $path, $payload, $parameters, $paginator, false, $headers);
     }
 }

src/Id/Auth/TokenGuard.php

@@ -9,38 +9,39 @@ use Exception;
 use Firebase\JWT\JWT;
 use Firebase\JWT\Key;
 use Illuminate\Auth\AuthenticationException;
-use Illuminate\Auth\GuardHelpers;
+use Illuminate\Contracts\Auth\Authenticatable;
-use Illuminate\Container\Container;
-use Illuminate\Contracts\Container\BindingResolutionException;
-use Illuminate\Contracts\Debug\ExceptionHandler;
 use Illuminate\Contracts\Encryption\Encrypter;
 use Illuminate\Cookie\CookieValuePrefix;
 use Illuminate\Cookie\Middleware\EncryptCookies;
-use Illuminate\Foundation\Auth\User as Authenticatable;
 use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Cache;
 use stdClass;
 use Throwable;
 
+/**
+ * Resolves the user of a request from an Anikeen ID access token (JWT, "Authorization: Bearer …")
+ * or from the encrypted token cookie of CreateFreshApiToken.
+ *
+ * A bearer token is verified with the JwtParser (signature, expiry). Its `sub` is the user's
+ * Anikeen ID, looked up by the provider (AnikeenIdUserProvider::retrieveByAnikeenId(), column
+ * `anikeen_id` by default). The token is attached to the user: `$user->anikeenTokenCan('scope')`.
+ *
+ * With `services.anikeen.verify_revocation` the token is also checked against Anikeen ID
+ * (GET v1/user, cached per token for `services.anikeen.revocation_cache_ttl` seconds), so
+ * revoked tokens stop working before they expire.
+ */
 class TokenGuard
 {
-    use GuardHelpers;
+    public function __construct(
-
+        protected UserProvider $provider,
-    private Encrypter $encrypter;
+        private Encrypter $encrypter,
-
+        private JwtParser $jwtParser
-    private JwtParser $jwtParser;
+    ) {
-
+        //
-    public function __construct(UserProvider $provider, Encrypter $encrypter, JwtParser $jwtParser)
-    {
-        $this->provider = $provider;
-        $this->encrypter = $encrypter;
-        $this->jwtParser = $jwtParser;
     }
 
     /**
      * Get the user for the incoming request.
-     *
-     * @throws BindingResolutionException
-     * @throws Throwable
      */
     public function user(Request $request): ?Authenticatable
     {
@@ -55,9 +56,6 @@ class TokenGuard
 
     /**
      * Authenticate the incoming request via the Bearer token.
-     *
-     * @throws BindingResolutionException
-     * @throws Throwable
      */
     protected function authenticateViaBearerToken(Request $request): ?Authenticatable
     {
@@ -65,51 +63,97 @@ class TokenGuard
             return null;
         }
 
-        // If the access token is valid we will retrieve the user according to the user ID
+        // client credentials tokens have no user
-        // associated with the token. We will use the provider implementation which may
+        if (!is_scalar($token->sub ?? null) || (string) $token->sub === '') {
-        // be used to retrieve users from Eloquent. Next, we'll be ready to continue.
+            return null;
-        /** @var Authenticatable|HasAnikeenTokens $user */
+        }
-        $user = $this->provider->retrieveById(
-            $request->attributes->get('oauth_user_id') ?: null
-        );
 
-        return $user?->withAnikeenAccessToken($token);
+        if (!$this->tokenIsActive($token, (string) $request->bearerToken())) {
+            return null;
+        }
 
+        /** @var Authenticatable|HasAnikeenTokens|null $user */
+        $user = $this->retrieveUser((string) $token->sub);
+
+        return $user && method_exists($user, 'withAnikeenAccessToken')
+            ? $user->withAnikeenAccessToken($token)
+            : $user;
     }
 
     /**
-     * Authenticate and get the incoming request via the Bearer token.
+     * Verify the Bearer token and expose its claims as request attributes.
-     *
-     * @throws BindingResolutionException
-     * @throws Throwable
      */
     protected function validateRequestViaBearerToken(Request $request): ?stdClass
     {
         try {
             $decoded = $this->jwtParser->decode($request);
-
+        } catch (AuthenticationException) {
-            $request->attributes->set('oauth_access_token_id', $decoded->jti);
-            $request->attributes->set('oauth_client_id', $decoded->aud);
-            $request->attributes->set('oauth_client_trusted', $decoded->client->trusted);
-            $request->attributes->set('oauth_user_id', $decoded->sub);
-            $request->attributes->set('oauth_scopes', $decoded->scopes);
-
-            return $decoded;
-        } catch (AuthenticationException $e) {
-            $request->headers->set('Authorization', '', true);
-
-            Container::getInstance()->make(
-                ExceptionHandler::class
-            )->report($e);
-
             return null;
         }
+
+        $decoded->scopes = array_values(array_filter((array) ($decoded->scopes ?? []), 'is_string'));
+
+        $request->attributes->set('oauth_access_token_id', $decoded->jti ?? null);
+        $request->attributes->set('oauth_client_id', $decoded->aud ?? null);
+        $request->attributes->set('oauth_client_trusted', $decoded->client->trusted ?? null);
+        $request->attributes->set('oauth_user_id', $decoded->sub ?? null);
+        $request->attributes->set('oauth_scopes', $decoded->scopes);
+
+        return $decoded;
+    }
+
+    /**
+     * Whether Anikeen ID still accepts the token (only with services.anikeen.verify_revocation).
+     */
+    protected function tokenIsActive(stdClass $token, string $jwt): bool
+    {
+        if (!config('services.anikeen.verify_revocation')) {
+            return true;
+        }
+
+        $key = 'anikeen-id:token-active:' . hash('sha256', $jwt);
+
+        if (($cached = Cache::get($key)) !== null) {
+            return (bool) $cached;
+        }
+
+        try {
+            $result = (clone app(AnikeenId::class))->withToken($jwt)->getAuthedUser();
+        } catch (Throwable) {
+            return false; // Anikeen ID unreachable: fail closed, ask again next time
+        }
+
+        $status = $result->response?->getStatusCode();
+
+        if ($result->success()) {
+            $active = true;
+        } elseif (in_array($status, [401, 403], true)) {
+            $active = false;
+        } else {
+            return false; // server error: fail closed without caching
+        }
+
+        $ttl = (int) config('services.anikeen.revocation_cache_ttl', 300);
+        if (isset($token->exp)) {
+            $ttl = max(1, min($ttl, (int) $token->exp - time()));
+        }
+        Cache::put($key, $active, $ttl);
+
+        return $active;
+    }
+
+    /**
+     * Find the local user of an Anikeen ID.
+     */
+    protected function retrieveUser(string $anikeenId): ?Authenticatable
+    {
+        return $this->provider->retrieveByAnikeenId($anikeenId);
     }
 
     /**
      * Authenticate the incoming request via the token cookie.
      */
-    protected function authenticateViaCookie(Request $request): mixed
+    protected function authenticateViaCookie(Request $request): ?Authenticatable
     {
         if (!$token = $this->getTokenViaCookie($request)) {
             return null;
@@ -118,9 +162,11 @@ class TokenGuard
         // If this user exists, we will return this user and attach a "transient" token to
         // the user model. The transient token assumes it has all scopes since the user
         // is physically logged into the application via the application's interface.
-        /** @var Authenticatable|HasAnikeenTokens $user */
+        /** @var Authenticatable|HasAnikeenTokens|null $user */
-        if ($user = $this->provider->retrieveById($token['sub'])) {
+        if ($user = $this->retrieveUser((string) $token['sub'])) {
-            return $user->withAnikeenAccessToken((object)['scopes' => ['*']]);
+            return method_exists($user, 'withAnikeenAccessToken')
+                ? $user->withAnikeenAccessToken((object) ['scopes' => ['*']])
+                : $user;
         }
 
         return null;
@@ -136,15 +182,18 @@ class TokenGuard
         // database. If we can't decrypt the value we'll bail out with a null return.
         try {
             $token = $this->decodeJwtTokenCookie($request);
-        } catch (Exception $e) {
+        } catch (Exception) {
+            return null;
+        }
+
+        if (!isset($token['sub'], $token['expiry'])) {
             return null;
         }
 
         // We will compare the CSRF token in the decoded API token against the CSRF header
         // sent with the request. If they don't match then this request isn't sent from
         // a valid source and we won't authenticate the request for further handling.
-        if (!AnikeenId::$ignoreCsrfToken && (!$this->validCsrf($token, $request) ||
+        if (time() >= $token['expiry'] || (!AnikeenId::$ignoreCsrfToken && !$this->validCsrf($token, $request))) {
-                time() >= $token['expiry'])) {
             return null;
         }
 
@@ -156,7 +205,7 @@ class TokenGuard
      */
     protected function decodeJwtTokenCookie(Request $request): array
     {
-        return (array)JWT::decode(
+        return (array) JWT::decode(
             CookieValuePrefix::remove($this->encrypter->decrypt($request->cookie(AnikeenId::cookie()), AnikeenId::$unserializesCookies)),
             new Key(
                 $this->encrypter->getKey(),
@@ -171,8 +220,8 @@ class TokenGuard
     protected function validCsrf(array $token, Request $request): bool
     {
         return isset($token['csrf']) && hash_equals(
-                $token['csrf'], $this->getTokenFromRequest($request)
+            $token['csrf'], $this->getTokenFromRequest($request)
-            );
+        );
     }
 
     /**
@@ -186,7 +235,7 @@ class TokenGuard
             $token = CookieValuePrefix::remove($this->encrypter->decrypt($header, static::serialized()));
         }
 
-        return $token;
+        return (string) $token;
     }
 
     /**
@@ -196,4 +245,4 @@ class TokenGuard
     {
         return EncryptCookies::serialized('XSRF-TOKEN');
     }
-}
+}

src/Id/Auth/UserProvider.php

@@ -2,6 +2,7 @@
 
 namespace Anikeen\Id\Auth;
 
+use Anikeen\Id\AnikeenId;
 use Illuminate\Contracts\Auth\Authenticatable;
 use Illuminate\Contracts\Auth\UserProvider as Base;
 
@@ -10,11 +11,33 @@ class UserProvider implements Base
     /**
      * Create a new AnikeenId user provider.
      */
-    public function __construct(protected Base $provider, protected string $providerName)
+    public function __construct(protected Base $provider, protected string $providerName, protected ?string $column = null)
     {
         //
     }
 
+    /**
+     * The column that holds a user's Anikeen ID: the provider's `column`, else
+     * `services.anikeen.user_id_column`, else AnikeenId::getUserIdField() (`anikeen_id`).
+     */
+    public function column(): string
+    {
+        return $this->column ?: (config('services.anikeen.user_id_column') ?: AnikeenId::getUserIdField());
+    }
+
+    /**
+     * Find the user of an Anikeen ID (the `sub` of an access token).
+     */
+    public function retrieveByAnikeenId(string $anikeenId): ?Authenticatable
+    {
+        if (method_exists($this->provider, 'retrieveByAnikeenId')) {
+            return $this->provider->retrieveByAnikeenId($anikeenId);
+        }
+
+        // eloquent / database providers: a plain where on the column
+        return $this->provider->retrieveByCredentials([$this->column() => $anikeenId]);
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -65,6 +88,6 @@ class UserProvider implements Base
 
     public function rehashPasswordIfRequired(Authenticatable $user, #[\SensitiveParameter] array $credentials, bool $force = false)
     {
-        // TODO: Implement rehashPasswordIfRequired() method.
+        $this->provider->rehashPasswordIfRequired($user, $credentials, $force);
     }
 }

src/Id/Billable.php

@@ -9,6 +9,7 @@ use Anikeen\Id\Concerns\ManagesInvoices;
 use Anikeen\Id\Concerns\ManagesOrders;
 use Anikeen\Id\Concerns\ManagesPaymentMethods;
 use Anikeen\Id\Concerns\ManagesProfile;
+use Anikeen\Id\Concerns\ManagesUserPreferences;
 use Anikeen\Id\Concerns\ManagesSubscriptions;
 use Anikeen\Id\Concerns\ManagesTaxation;
 use Anikeen\Id\Concerns\ManagesTransactions;
@@ -27,8 +28,26 @@ trait Billable
     use ManagesSubscriptions;
     use ManagesTaxation;
     use ManagesTransactions;
+    use ManagesUserPreferences;
     use ManagesUserSshKeys;
 
+    /*
+     * API results cached per instance. Declared, so Eloquent models don't take them for
+     * attributes (an undeclared property goes through Model::__set and save() then fails
+     * with "no such column").
+     */
+    protected mixed $addressesCache = null;
+    protected mixed $countriesCache = null;
+    protected mixed $defaultPaymentMethodCache = null;
+    protected mixed $invoicesCache = null;
+    protected mixed $ordersCache = null;
+    protected mixed $paymentMethodsCache = null;
+    /** @var array<string, \Anikeen\Id\Resources\Preferences> by namespace */
+    protected array $preferencesCache = [];
+    protected mixed $subscriptionsCache = null;
+    protected mixed $transactionsCache = null;
+    protected mixed $userDataCache = null;
+
     /**
      * Get the currently authenticated user.
      *

src/Id/Concerns/HasConfirmationUrl.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Anikeen\Id\Concerns;
+
+/**
+ * Orders and subscriptions created by third-party apps are confirmed by the user on Anikeen ID.
+ */
+trait HasConfirmationUrl
+{
+    /**
+     * Where the user confirms (or cancels) this booking, or null once it was checked out.
+     *
+     * Afterwards the user is sent back to $returnUrl with `status` (completed, pending or
+     * cancelled) and `order` or `subscription`. The return URL must have the origin of one of
+     * the app's redirect URIs. Check the status through the API; don't trust the query string.
+     */
+    public function confirmationUrl(?string $returnUrl = null): ?string
+    {
+        $url = $this->confirmation_url ?? null;
+
+        if (!$url || !$returnUrl) {
+            return $url ?: null;
+        }
+
+        return $url . (str_contains($url, '?') ? '&' : '?') . http_build_query(['return_url' => $returnUrl]);
+    }
+}

src/Id/Concerns/HasSubscriptionStatus.php

@@ -0,0 +1,90 @@
+<?php
+
+namespace Anikeen\Id\Concerns;
+
+use Anikeen\Id\Enums\SubscriptionStatus;
+
+/**
+ * The state of a subscription, derived from its fields the same way Anikeen ID derives `status`
+ * (so it also works with responses that only carry the fields).
+ */
+trait HasSubscriptionStatus
+{
+    /**
+     * One of the SubscriptionStatus constants: draft, trial, active, paused, cancelling, expired
+     * or cancelled.
+     */
+    public function status(): string
+    {
+        $active = (bool) $this->active;
+        $started = !empty($this->starts_at);
+
+        return match (true) {
+            (bool) $this->cancelled => SubscriptionStatus::CANCELLED,
+            !$active && !$started => SubscriptionStatus::DRAFT,
+            $active && !empty($this->cancels_at) => SubscriptionStatus::CANCELLING,
+            $active && !$this->autorenew => SubscriptionStatus::PAUSED,
+            $active && !empty($this->trial_ends_at) && strtotime($this->trial_ends_at) > time() => SubscriptionStatus::TRIAL,
+            $active => SubscriptionStatus::ACTIVE,
+            !$this->autorenew && $started => SubscriptionStatus::EXPIRED,
+            default => SubscriptionStatus::INACTIVE,
+        };
+    }
+
+    /**
+     * Not checked out or confirmed yet (third-party apps: send the user to confirmationUrl()).
+     */
+    public function isDraft(): bool
+    {
+        return $this->status() === SubscriptionStatus::DRAFT;
+    }
+
+    /**
+     * Running and paid: active, in trial, paused or with a scheduled cancellation. Grant access
+     * while this is true.
+     */
+    public function isActive(): bool
+    {
+        return in_array($this->status(), [SubscriptionStatus::TRIAL, SubscriptionStatus::ACTIVE, SubscriptionStatus::PAUSED, SubscriptionStatus::CANCELLING], true);
+    }
+
+    /**
+     * In its free trial: running, nothing billed until trial_ends_at.
+     */
+    public function isTrial(): bool
+    {
+        return $this->status() === SubscriptionStatus::TRIAL;
+    }
+
+    /**
+     * Paused: runs until the paid period ends, then expires (resume() to continue).
+     */
+    public function isPaused(): bool
+    {
+        return $this->status() === SubscriptionStatus::PAUSED;
+    }
+
+    /**
+     * Running until a scheduled cancellation takes effect.
+     */
+    public function isCancelling(): bool
+    {
+        return $this->status() === SubscriptionStatus::CANCELLING;
+    }
+
+    /**
+     * Paused and ran out: resume() starts a new period.
+     */
+    public function isExpired(): bool
+    {
+        return $this->status() === SubscriptionStatus::EXPIRED;
+    }
+
+    /**
+     * Cancelled for good.
+     */
+    public function isCancelled(): bool
+    {
+        return $this->status() === SubscriptionStatus::CANCELLED;
+    }
+}

src/Id/Concerns/IsCheckoutSession.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Anikeen\Id\Concerns;
+
+/**
+ * Reading a checkout session (see AppCheckoutSession and CheckoutSession).
+ */
+trait IsCheckoutSession
+{
+    /**
+     * Where the user confirms (or cancels) all of the session's subscriptions, or null once the
+     * session is no longer open. The user then returns to the session's `return_url` with
+     * `status` (completed or cancelled when confirming or cancelling; expired only from the
+     * "back to app" link of a session that had expired) and `checkout_session` (the id). Check the
+     * status through the API or the checkout.* webhooks; don't trust the query string.
+     */
+    public function confirmationUrl(): ?string
+    {
+        return $this->confirmation_url ?: null;
+    }
+
+    public function isOpen(): bool
+    {
+        return $this->status === self::STATUS_OPEN;
+    }
+
+    /**
+     * Confirmed: all of its subscriptions are running.
+     */
+    public function isCompleted(): bool
+    {
+        return $this->status === self::STATUS_COMPLETED;
+    }
+
+    /**
+     * Cancelled or expired: all of its drafts were cancelled.
+     */
+    public function isCancelled(): bool
+    {
+        return in_array($this->status, [self::STATUS_CANCELLED, self::STATUS_EXPIRED], true);
+    }
+
+    /**
+     * @return list<string>
+     */
+    public function subscriptionIds(): array
+    {
+        return array_values((array) ($this->subscription_ids ?? []));
+    }
+}

src/Id/Concerns/ManagesBalance.php

@@ -31,7 +31,13 @@ trait ManagesBalance
 
     /**
      * Billing overview of the current user: current_balance, current_charges, vat_rate,
-     * has_billing_address, has_default_payment_method, open_orders.
+     * has_billing_address, has_default_payment_method, open_orders and billing_limit.
+     *
+     * billing_limit is the user's monthly billing limit {object: "billing_limit", user_id,
+     * currency, basis, limit, used, remaining, remaining_net, vat_rate, reached, resets_at,
+     * version} (`limit`, `remaining` and `remaining_net` null without a limit; wrap it in
+     * `new \Anikeen\Id\Resources\BillingLimit(…)` for its helpers), or null while the user has no
+     * limit and can't set one yet. Older Anikeen ID releases don't send the key.
      *
      * @throws Throwable
      */

src/Id/Concerns/ManagesPreferences.php

@@ -0,0 +1,107 @@
+<?php
+
+namespace Anikeen\Id\Concerns;
+
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Exceptions\PreconditionFailedException;
+use Anikeen\Id\Resources\Preference;
+use Anikeen\Id\Resources\Preferences;
+use Anikeen\Id\Support\AppRequest;
+use Anikeen\Id\Support\PreferenceRequest;
+
+/**
+ * Preferences of any user, with the app's own token (client credentials, scope
+ * `preferences:client`). Anikeen has to register the app for each namespace it uses: its own
+ * namespaces (read, write, lookup), read access to another app's namespace, or access to `global`.
+ * Without it every call fails with 403 "client_not_trusted" or 404 "namespace_not_found".
+ */
+trait ManagesPreferences
+{
+    /**
+     * All preferences of a user in a namespace, sorted by key.
+     *
+     * @throws ApiException 404 "namespace_not_found", "user_not_found" (also deleted users), …
+     */
+    public function preferencesByUserId(string $userId, string $namespace): Preferences
+    {
+        return Preferences::builder(fn () => AppRequest::send('GET', $this->userPreferencePath($userId, $namespace)));
+    }
+
+    /**
+     * One preference of a user.
+     *
+     * @throws ApiException 404 "preference_not_found" when the key isn't set, "user_not_found", …
+     */
+    public function preferenceByUserId(string $userId, string $namespace, string $key): Preference
+    {
+        return new Preference(fn () => AppRequest::send('GET', $this->userPreferencePath($userId, $namespace, $key)));
+    }
+
+    /**
+     * Set a preference of a user. The value is any JSON value (pass `(object) []` for `{}`), at
+     * most 2048 bytes and 4 levels deep. Writing the value already stored changes nothing and
+     * succeeds, also when a precondition would fail, so a retried write is safe.
+     *
+     * @param int|null $ifVersion only if the stored version is this one (`If-Match`)
+     * @param bool $createOnly only if the key isn't set yet (`If-None-Match: *`); not with $ifVersion
+     * @throws PreconditionFailedException 412 "preference_version_mismatch" / "preference_exists",
+     *     with currentVersion()
+     * @throws ApiException 403 "namespace_read_only", 409 "preference_value_taken" (a unique key),
+     *     422 "invalid_key", "forbidden_key", "value_too_large", "preference_limit_exceeded", …
+     */
+    public function setPreferenceByUserId(string $userId, string $namespace, string $key, mixed $value, ?int $ifVersion = null, bool $createOnly = false): Preference
+    {
+        $headers = PreferenceRequest::conditions($ifVersion, $createOnly);
+
+        return new Preference(fn () => AppRequest::send('PUT', $this->userPreferencePath($userId, $namespace, $key), ['value' => $value], [], $headers));
+    }
+
+    /**
+     * Delete a preference of a user.
+     *
+     * @param int|null $ifVersion only if the stored version is this one (`If-Match`)
+     * @throws PreconditionFailedException 412 "preference_version_mismatch", with currentVersion()
+     * @throws ApiException 404 "preference_not_found" when the key isn't set, …
+     */
+    public function deletePreferenceByUserId(string $userId, string $namespace, string $key, ?int $ifVersion = null): void
+    {
+        AppRequest::send('DELETE', $this->userPreferencePath($userId, $namespace, $key), null, [], PreferenceRequest::conditions($ifVersion));
+    }
+
+    /**
+     * The ID of the user holding a value of a unique key in one of the app's own namespaces, e.g.
+     * the user of a payment provider's customer ID. The value is sent in the body, never in the URL.
+     *
+     * @return string|null null when no (not deleted) user holds the value
+     * @throws ApiException 422 "key_not_unique", "invalid_unique_value", 403 "lookup_not_allowed", …
+     */
+    public function findUserIdByPreference(string $namespace, string $key, string $value): ?string
+    {
+        try {
+            $result = AppRequest::send('POST', PreferenceRequest::path('v1/client/preferences', $namespace, 'lookup'), [
+                'key' => $key,
+                'value' => $value,
+            ]);
+        } catch (ApiException $e) {
+            // only Anikeen ID's own answer means "nobody holds it", not e.g. an unknown namespace
+            if ($e->isNotFound() && $e->error === 'preference_not_found') {
+                return null;
+            }
+
+            throw $e;
+        }
+
+        return $result->data->user_id;
+    }
+
+    private function userPreferencePath(string $userId, string $namespace, ?string $key = null): string
+    {
+        $segments = [$userId, 'preferences', $namespace];
+
+        if ($key !== null) {
+            $segments[] = $key;
+        }
+
+        return PreferenceRequest::path('v1/client/users', ...$segments);
+    }
+}

src/Id/Concerns/ManagesSubscriptions.php

@@ -2,8 +2,12 @@
 
 namespace Anikeen\Id\Concerns;
 
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Resources\AppCheckoutSessions;
 use Anikeen\Id\Resources\AppOrders;
 use Anikeen\Id\Resources\AppSubscriptions;
+use Anikeen\Id\Resources\CheckoutSessions;
 use Anikeen\Id\Resources\Subscriptions;
 use Throwable;
 
@@ -37,6 +41,24 @@ trait ManagesSubscriptions
         return new AppSubscriptions($this);
     }
 
+    /**
+     * Checkout sessions for the user, created with the app's own token (trusted apps only, scope
+     * subscriptions:client): the user confirms several subscriptions at once on Anikeen ID.
+     */
+    public function appCheckoutSessions(): AppCheckoutSessions
+    {
+        return new AppCheckoutSessions($this);
+    }
+
+    /**
+     * Checkout sessions with the user's own access token (any app): the user confirms several
+     * subscriptions at once on Anikeen ID.
+     */
+    public function checkoutSessions(): CheckoutSessions
+    {
+        return new CheckoutSessions($this);
+    }
+
     /**
      * The user's orders that bill the app's subscriptions, read with the app's own token
      * (trusted apps only, scope orders:client), e.g. ->pending() for unpaid ones.
@@ -45,4 +67,20 @@ trait ManagesSubscriptions
     {
         return new AppOrders($this);
     }
-}␍
+
+    /**
+     * A link to the user's billing pages on Anikeen ID that needs no login, created with the app's
+     * own token (trusted apps only, scope subscriptions:client or orders:client), e.g. for a
+     * "Manage billing" button; see AnikeenId::createBillingPortalLinkForUser() for the attributes
+     * (return_url, group, flow). Single use and valid for about 15 minutes: create it when the
+     * user clicks and redirect right away.
+     *
+     * @param array{return_url?: null|string, group?: null|string, flow?: null|string} $attributes
+     *
+     * @throws ApiException
+     */
+    public function appBillingPortalUrl(array $attributes = []): string
+    {
+        return app(AnikeenId::class)->createBillingPortalLinkForUser($this->appSubscriptions()->userId(), $attributes)->url;
+    }
+}

src/Id/Concerns/ManagesUserBilling.php

@@ -2,8 +2,13 @@
 
 namespace Anikeen\Id\Concerns;
 
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Resources\AppCharge;
+use Anikeen\Id\Resources\AppCheckoutSessions;
 use Anikeen\Id\Resources\AppOrders;
+use Anikeen\Id\Resources\BillingLimit;
 use Anikeen\Id\Result;
+use Anikeen\Id\Support\AppRequest;
 use Throwable;
 
 /**
@@ -19,11 +24,57 @@ trait ManagesUserBilling
         return new AppOrders();
     }
 
+    /**
+     * Checkout sessions of the app for any user, e.g. to look one up from a checkout.* webhook
+     * (create() then needs a user_id).
+     */
+    public function appCheckoutSessions(): AppCheckoutSessions
+    {
+        return new AppCheckoutSessions();
+    }
+
+    /**
+     * A link to a user's billing pages on Anikeen ID that needs no login, like Stripe's customer
+     * portal, e.g. for a "Manage billing" button of an app that bills another user's account (a
+     * team owner) without that user's token (trusted apps, scope subscriptions:client or
+     * orders:client). The link is single use and valid for about 15 minutes: create it when the
+     * user clicks and redirect right away, don't store it. It opens a portal session for that user
+     * only (no login, nobody signed in) with only the flow's billing pages and only what bills the
+     * app's subscriptions (of the group), leading back to return_url; it ends after an hour
+     * without activity.
+     *
+     * @param string $userId The user's Anikeen ID.
+     * @param array{
+     *     return_url?: null|string,
+     *     group?: null|string,
+     *     flow?: null|string
+     * } $attributes return_url: "Back to the app" (same origin as one of the app's redirect URIs,
+     *               422 otherwise).
+     *               group: only this group's subscriptions and the orders, invoices and
+     *               transactions billing them.
+     *               flow: overview (default), payment_method, payment_method_update (straight to
+     *               replacing the payment method, e.g. after a failed payment), invoices,
+     *               subscriptions or orders.
+     * @return object {object: "billing_portal_link", url, user_id, flow, group, return_url, expires_at}
+     *
+     * @throws ApiException 403 untrusted app or missing scope, 404 unknown user, 422 validation
+     */
+    public function createBillingPortalLinkForUser(string $userId, array $attributes = []): object
+    {
+        return AppRequest::send('POST', sprintf('v1/client/users/%s/billing-portal', $userId), $attributes)->data;
+    }
+
     /**
      * Create an order for a user (VAT from the billing address). With `checkout`, it is paid right
      * away: with the given `transaction` (a payment captured elsewhere) or by charging the user's
      * default payment method (402 when declined; the order stays pending and is retried).
      *
+     * With `confirm`, the user confirms and pays it on Anikeen ID instead (e.g. a top-up): the
+     * order stays a draft with `confirmation_url` (send the user there) and is cancelled if not
+     * confirmed within 24 hours (`expires_at`; afterwards checking it out answers 409
+     * "confirmation_expired"). Webhooks: order.created, order.completed once paid, or
+     * order.cancelled when the user declines or it expires.
+     *
      * @param string $userId The user's Anikeen ID.
      * @param array{
      *     group?: string,
@@ -31,13 +82,20 @@ trait ManagesUserBilling
      *     billing_address?: array,
      *     shipping_address_id?: string,
      *     shipping_address?: array,
-     *     items: array<array{type: string, name: string, description?: string, price?: float|string, gross_price?: float|string, unit: string, units: int}>,
+     *     items: array<array{type: string, name: string, description?: string, image_url?: string, price?: float|string, gross_price?: float|string, unit: string, units: int}>,
      *     checkout?: bool,
+     *     confirm?: bool,
+     *     return_url?: null|string,
+     *     metadata?: null|array,
      *     transaction_id?: string,
      *     transaction?: array,
      *     invoice_date?: string,
      *     currency_iso?: string
-     * } $attributes
+     * } $attributes confirm: needs items, can't be combined with checkout or a transaction.
+     *               return_url: where the user returns after confirming, with `status` and
+     *               `order` (same origin as one of the app's redirect URIs, 422 otherwise).
+     *               metadata: the app's own data (max. 50 keys), returned as is in the API and
+     *               the order webhooks.
      * @throws Throwable
      */
     public function createOrderForUser(string $userId, array $attributes): Result
@@ -67,4 +125,101 @@ trait ManagesUserBilling
     {
         return $this->asApp()->request('POST', 'v1/admin/transactions', [...$attributes, 'user_id' => $userId]);
     }
+
+    /**
+     * Book a charge onto a user's open monthly bill of the app, e.g. a shipped item: one line,
+     * no subscription, charged with the bill on the 1st. Trusted apps that Anikeen allowed to
+     * charge (with a maximum per charge), for users connected to the app (they authorised it or
+     * the app bills them). The user's billing limit is checked when it is booked.
+     *
+     * Retrying with the same idempotency key and the same fields returns the existing charge
+     * (also after the limit was reached); other fields with that key: 409
+     * "idempotency_key_conflict" (`charge_id` in body()).
+     *
+     * @param string $userId The user's Anikeen ID.
+     * @param array{
+     *     idempotency_key: string,
+     *     name: string,
+     *     description?: null|string,
+     *     type?: string,
+     *     quantity: int,
+     *     unit_price: float|int|string,
+     *     currency_iso?: string,
+     *     group?: null|string,
+     *     occurred_at?: string,
+     *     reference?: null|string,
+     *     metadata?: null|array<string, string>,
+     *     image_url?: null|string
+     * } $attributes idempotency_key: unique per app and user, ≤ 255 (e.g. "shipment-123").
+     *               name: the line on the bill, ≤ 255. description: ≤ 255.
+     *               type: digital (default), physical or physical-reduced (the VAT treatment).
+     *               quantity: 1–10000 pieces. unit_price: net per piece, > 0, ≤ 100000, up to 6
+     *               decimals; quantity × unit_price rounded to cents must be at least 0.01.
+     *               currency_iso: EUR only (default).
+     *               group: null, or a group in which the app already bills the user (a running
+     *               subscription or an open monthly bill of the app).
+     *               occurred_at: the service date, not in the future, at most 31 days ago
+     *               (default now).
+     *               reference: the app's own id (≤ 255). metadata: ≤ 20 keys (≤ 40 characters),
+     *               string values ≤ 500. Both are not on the bill; put nothing sensitive there.
+     *               image_url: http(s) URL of an image for the line.
+     *
+     * @throws ApiException 403 "client_not_allowed" (not a trusted app), "charges_not_enabled";
+     *     404 "user_not_found" (unknown, deleted or not connected); 409 "billing_limit_reached"
+     *     (isBillingLimitReached(); body() has limit, used, remaining, remaining_net, required,
+     *     currency, resets_at), "charge_exceeds_maximum" (+ max_charge_net),
+     *     "group_not_allowed", "idempotency_key_conflict" (+ charge_id),
+     *     "billing_address_missing"; 422 validation; 429 "too_many_requests"
+     */
+    public function createChargeForUser(string $userId, array $attributes): AppCharge
+    {
+        return new AppCharge(AppRequest::send('POST', $this->chargesPath($userId), $attributes)->data);
+    }
+
+    /**
+     * A charge of the app (or of a client delegated to the same app) for a user.
+     *
+     * @throws ApiException 403 "client_not_allowed", "charges_not_enabled"; 404 "user_not_found",
+     *     "charge_not_found"; 429 "too_many_requests"
+     */
+    public function findChargeForUser(string $userId, string $chargeId): AppCharge
+    {
+        return new AppCharge(AppRequest::send('GET', $this->chargesPath($userId, $chargeId))->data);
+    }
+
+    /**
+     * Void a charge while its bill is open: the line is removed and the bill's total drops. An
+     * already voided charge is returned as it is. Once the bill is closed only a refund of the
+     * order by Anikeen credits it.
+     *
+     * @param string|null $reason why (≤ 255), stored with the charge
+     * @throws ApiException 409 "charge_already_billed" (+ charge_id); 404 "charge_not_found",
+     *     "user_not_found"; 403 "client_not_allowed", "charges_not_enabled"; 429 "too_many_requests"
+     */
+    public function voidChargeForUser(string $userId, string $chargeId, ?string $reason = null): AppCharge
+    {
+        $payload = $reason === null ? null : ['reason' => $reason];
+
+        return new AppCharge(AppRequest::send('POST', $this->chargesPath($userId, $chargeId) . '/void', $payload)->data);
+    }
+
+    /**
+     * A user's monthly billing limit as the app sees it, e.g. to pause paid features while it is
+     * reached. Advisory only: it reserves nothing; a charge is checked when it is booked. Trusted
+     * apps that may charge or that Anikeen allowed to read limits, for users connected to the app.
+     *
+     * @throws ApiException 403 "client_not_allowed", "billing_limit_not_enabled"; 404
+     *     "user_not_found"; 429 "too_many_requests"
+     */
+    public function billingLimitForUser(string $userId): BillingLimit
+    {
+        return new BillingLimit(AppRequest::send('GET', sprintf('v1/client/users/%s/billing-limit', rawurlencode($userId)))->data);
+    }
+
+    private function chargesPath(string $userId, ?string $chargeId = null): string
+    {
+        $path = sprintf('v1/client/users/%s/charges', rawurlencode($userId));
+
+        return $chargeId === null ? $path : $path . '/' . rawurlencode($chargeId);
+    }
 }

src/Id/Concerns/ManagesUserPreferences.php

@@ -0,0 +1,96 @@
+<?php
+
+namespace Anikeen\Id\Concerns;
+
+use Anikeen\Id\Enums\SharedPreference;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Exceptions\PreconditionFailedException;
+use Anikeen\Id\Resources\Preference;
+use Anikeen\Id\Resources\Preferences;
+use Anikeen\Id\Support\PreferenceRequest;
+use GuzzleHttp\Exception\GuzzleException;
+
+/**
+ * The user's shared preferences (`global`, e.g. SharedPreference::APPEARANCE), with the user's
+ * token (scope `preferences` or `preferences:read`). User tokens reach `global` only; an app's
+ * own namespace needs the app token (AnikeenId::preferencesByUserId()).
+ */
+trait ManagesUserPreferences
+{
+    /**
+     * The user's shared preferences, sorted by key. Cached on this instance; set and delete clear it.
+     *
+     * @throws ApiException
+     */
+    public function globalPreferences(): Preferences
+    {
+        $namespace = SharedPreference::NAMESPACE;
+
+        if (!isset($this->preferencesCache[$namespace])) {
+            $anikeenId = $this->anikeenId();
+
+            $this->preferencesCache[$namespace] = Preferences::builder(
+                fn () => $anikeenId->get(PreferenceRequest::path('v1/preferences', $namespace))
+            );
+        }
+
+        return $this->preferencesCache[$namespace];
+    }
+
+    /**
+     * The value of a shared preference, or $default when the user hasn't set it.
+     *
+     * @throws ApiException
+     */
+    public function globalPreference(string $key, mixed $default = null): mixed
+    {
+        return $this->globalPreferences()->get($key, $default);
+    }
+
+    /**
+     * Set a shared preference of the user, e.g. setGlobalPreference(SharedPreference::APPEARANCE,
+     * Appearance::DARK). Only registered keys and values are accepted (422 "unknown_shared_key",
+     * "invalid_shared_value").
+     *
+     * @param int|null $ifVersion only if the stored version is this one (`If-Match`)
+     * @throws PreconditionFailedException 412 "preference_version_mismatch", with currentVersion()
+     * @throws ApiException
+     */
+    public function setGlobalPreference(string $key, mixed $value, ?int $ifVersion = null): Preference
+    {
+        $namespace = SharedPreference::NAMESPACE;
+        $headers = PreferenceRequest::conditions($ifVersion);
+        $anikeenId = $this->anikeenId();
+
+        try {
+            return new Preference(fn () => $anikeenId->put(PreferenceRequest::path('v1/preferences', $namespace, $key), ['value' => $value], [], null, $headers));
+        } finally {
+            unset($this->preferencesCache[$namespace]);
+        }
+    }
+
+    /**
+     * Delete a shared preference of the user.
+     *
+     * @param int|null $ifVersion only if the stored version is this one (`If-Match`)
+     * @throws PreconditionFailedException 412 "preference_version_mismatch", with currentVersion()
+     * @throws ApiException 404 "preference_not_found" when the key isn't set, …
+     */
+    public function deleteGlobalPreference(string $key, ?int $ifVersion = null): void
+    {
+        $namespace = SharedPreference::NAMESPACE;
+        $headers = PreferenceRequest::conditions($ifVersion);
+
+        try {
+            $result = $this->anikeenId()->delete(PreferenceRequest::path('v1/preferences', $namespace, $key), [], [], null, $headers);
+        } catch (GuzzleException $e) {
+            throw ApiException::unreachable($e);
+        } finally {
+            unset($this->preferencesCache[$namespace]);
+        }
+
+        if (!$result->success()) {
+            throw ApiException::fromResult($result);
+        }
+    }
+}

src/Id/Concerns/ManagesUsers.php

@@ -5,7 +5,9 @@ namespace Anikeen\Id\Concerns;
 
 use Anikeen\Id\ApiOperations\Get;
 use Anikeen\Id\ApiOperations\Post;
+use Anikeen\Id\Exceptions\ApiException;
 use Anikeen\Id\Result;
+use Anikeen\Id\Support\AppRequest;
 use Throwable;
 
 trait ManagesUsers
@@ -24,20 +26,32 @@ trait ManagesUsers
     }
 
     /**
-     * Creates a new user on behalf of the current user.
+     * Finds the account of an email address or creates it (trusted apps, app token). The email
+     * address is matched regardless of case; a new account stores it in lower case, unverified.
+     * An existing account is returned unchanged (only a missing name is filled in).
      *
      * @param array{
-     *       first_name: null|string,
+     *       name?: null|string,
-     *       last_name: null|string,
+     *       first_name?: null|string,
-     *       username: null|string,
+     *       last_name?: null|string,
+     *       username?: null|string,
      *       email: string,
-     *       password: null|string
+     *       password?: null|string,
+     *       password_confirmation?: null|string,
+     *       send_invitation?: bool
      *   } $attributes The user data
-     *     - first_name:  The first name (optional)
+     *     - name:                  The display name (optional)
-     *     - last_name:   The last name (optional)
+     *     - first_name:            The first name (optional, joined with last_name into name)
-     *     - username:    The username (optional)
+     *     - last_name:             The last name (optional, joined with first_name into name)
-     *     - email:       The email (required)
+     *     - username:              The username (optional)
-     *     - password:    The password (optional, can be reset by the user if not provided)
+     *     - email:                 The email (required)
+     *     - password:              The password (optional, can be reset by the user if not provided)
+     *     - password_confirmation: Defaults to password
+     *     - send_invitation:       Send the user an invitation mail with a link to set a password
+     *                              (optional, only when this call created the account without a
+     *                              password, never for an existing account)
+     * @return Result `data` is the user plus `created` (this call created the account) and
+     *     `invitation_sent` (the invitation mail was sent); 201 when created, 200 when it existed
      * @throws Throwable
      */
     public function createUser(array $attributes): Result
@@ -57,6 +71,30 @@ trait ManagesUsers
         return $this->asApp()->post('v1/admin/users', $attributes);
     }
 
+    /**
+     * Looks up the account of an email address without creating or changing anything (trusted
+     * apps, app token). The email address is matched regardless of case.
+     *
+     * `data` is `object{id: string, name: ?string, email: string, email_verified: bool,
+     * has_billing_address: bool}`.
+     *
+     * @return Result|null null when no account uses the email address
+     * @throws ApiException when the request fails for another reason
+     */
+    public function findUserByEmail(string $email): ?Result
+    {
+        try {
+            return AppRequest::send('POST', 'v1/admin/users/lookup', ['email' => $email]);
+        } catch (ApiException $e) {
+            // only Anikeen ID's own answer means "no account", not e.g. an unknown route
+            if ($e->isNotFound() && $e->error === 'user_not_found') {
+                return null;
+            }
+
+            throw $e;
+        }
+    }
+
     /**
      * Find the user of a social login or create it (trusted apps, app token).
      *

src/Id/Enums/Appearance.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Anikeen\Id\Enums;
+
+/**
+ * The values of the shared preference SharedPreference::APPEARANCE.
+ */
+class Appearance
+{
+    /** Follow the operating system. */
+    const SYSTEM = 'system';
+    const LIGHT = 'light';
+    const DARK = 'dark';
+
+    /**
+     * @return list<string>
+     */
+    public static function all(): array
+    {
+        return [self::SYSTEM, self::LIGHT, self::DARK];
+    }
+}

src/Id/Enums/CancellationReason.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Anikeen\Id\Enums;
+
+/**
+ * `cancellation_reason` of a subscription (and `data.reason` of `subscription.cancelled`): why
+ * Anikeen ID's billing ended it. Null when the user, the app or an admin cancelled it.
+ */
+class CancellationReason
+{
+    /** Its free trial (`trial_payment_method` optional) ended without a payment method: cancelled at the trial's end, nothing billed. */
+    const TRIAL_ENDED_WITHOUT_PAYMENT_METHOD = 'trial_ended_without_payment_method';
+}

src/Id/Enums/Scope.php

@@ -33,8 +33,25 @@ class Scope
     const TRANSACTIONS_READ = 'transactions:read';
     const TRANSACTIONS_CLIENT = 'transactions:client';
 
+    // The user's own shared preferences (`global`). PREFERENCES_CLIENT labels an app token for
+    // the preferences of any user; access to a namespace is granted by Anikeen, not by the scope.
+    const PREFERENCES = 'preferences';
+    const PREFERENCES_READ = 'preferences:read';
+    const PREFERENCES_CLIENT = 'preferences:client';
+
     const SSH_KEYS = 'ssh-keys';
     const SSH_KEYS_READ = 'ssh-keys:read';
 
+    // Products of the Anikeen Console (servers, floating IPs, hosting, domains, zones, object storage),
+    // read-only. Changing products needs `user`; there is no full `products` scope.
+    const PRODUCTS_READ = 'products:read';
+
+    // Reseller API of the Anikeen Console. A full scope includes reading; `user` and `*` do not
+    // open these endpoints, a token must carry the reseller scope itself.
+    const RESELLER_CUSTOMERS = 'reseller-customers';
+    const RESELLER_CUSTOMERS_READ = 'reseller-customers:read';
+    const RESELLER_GRANTS = 'reseller-grants';
+    const RESELLER_ORDERS = 'reseller-orders';
+
     const ADMIN = 'admin';
 }

src/Id/Enums/SharedPreference.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Anikeen\Id\Enums;
+
+/**
+ * The keys of the `global` preferences namespace, shared by all apps. Anikeen ID accepts only
+ * these keys there, each with its own values.
+ */
+class SharedPreference
+{
+    /** The namespace of the shared preferences. */
+    const NAMESPACE = 'global';
+
+    /** Light or dark mode: one of the Appearance constants. */
+    const APPEARANCE = 'appearance';
+}

src/Id/Enums/SubscriptionStatus.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Anikeen\Id\Enums;
+
+/**
+ * The state of a subscription, see Subscription::status() and AppSubscription::status().
+ */
+class SubscriptionStatus
+{
+    /** Created, not checked out or confirmed by the user yet. */
+    const DRAFT = 'draft';
+
+    /** Running and billed, in its trial period. */
+    const TRIAL = 'trial';
+
+    /** Running and billed. */
+    const ACTIVE = 'active';
+
+    /** Paused: runs until its paid period ends, then expires. */
+    const PAUSED = 'paused';
+
+    /** Running until a scheduled cancellation takes effect. */
+    const CANCELLING = 'cancelling';
+
+    /** Paused and ran out: can be resumed (new period) or cancelled. */
+    const EXPIRED = 'expired';
+
+    /** Cancelled for good. */
+    const CANCELLED = 'cancelled';
+
+    /** None of the above. */
+    const INACTIVE = 'inactive';
+}

src/Id/Enums/TrialPaymentMethod.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Anikeen\Id\Enums;
+
+/**
+ * `trial_payment_method` of a subscription with a free trial: whether the user needs a payment
+ * method to confirm it. Null on subscriptions without a trial.
+ */
+class TrialPaymentMethod
+{
+    /** A payment method is needed to confirm the trial (the default). */
+    const REQUIRED = 'required';
+
+    /**
+     * The trial can be confirmed without a payment method (if nothing else has to be paid). If the
+     * user still has none when the trial ends, the subscription is cancelled then instead of billed
+     * (`cancellation_reason` CancellationReason::TRIAL_ENDED_WITHOUT_PAYMENT_METHOD).
+     */
+    const OPTIONAL = 'optional';
+}

src/Id/Exceptions/ApiException.php

@@ -2,6 +2,8 @@
 
 namespace Anikeen\Id\Exceptions;
 
+use Anikeen\Id\Result;
+use Psr\Http\Message\ResponseInterface;
 use Throwable;
 
 /**
@@ -19,6 +21,54 @@ class ApiException extends ResourceException
         parent::__construct($message, $status, $previous);
     }
 
+    /**
+     * The exception for a failed request: Anikeen ID's message and error code, the HTTP status
+     * (0 when there was no response).
+     */
+    public static function fromResult(Result $result): static
+    {
+        $body = is_object($result->data) ? $result->data : null;
+        $status = $result->response()?->getStatusCode() ?? 0;
+
+        // a failed conditional write; subclasses (CollectionException) keep their own type
+        if ($status === 412 && static::class === self::class) {
+            return PreconditionFailedException::fromResult($result);
+        }
+
+        return new static(
+            rtrim((string) ($body->message ?? $result->error()), '.'),
+            $status,
+            $body->error ?? null,
+            $result->exception,
+        );
+    }
+
+    /**
+     * The exception for a request that got no response (network error, timeout).
+     */
+    public static function unreachable(Throwable $previous): static
+    {
+        return new static(sprintf('Anikeen ID is not reachable: %s', $previous->getMessage()), 0, null, $previous);
+    }
+
+    /**
+     * The JSON body of Anikeen ID's error response, null without one. Some errors carry details,
+     * e.g. `net_amount` of "elapsed_amount_exceeded".
+     */
+    public function body(): ?object
+    {
+        $previous = $this->getPrevious();
+        $response = $previous !== null && method_exists($previous, 'getResponse') ? $previous->getResponse() : null;
+
+        if (!$response instanceof ResponseInterface) {
+            return null;
+        }
+
+        $body = json_decode((string) $response->getBody());
+
+        return is_object($body) ? $body : null;
+    }
+
     public function isNotFound(): bool
     {
         return $this->status === 404;
@@ -29,6 +79,16 @@ class ApiException extends ResourceException
         return $this->status === 409;
     }
 
+    /**
+     * A charge was refused because it would take the user's open monthly bill above their billing
+     * limit (409 "billing_limit_reached"). body() has limit, used, remaining, remaining_net,
+     * required, currency and resets_at.
+     */
+    public function isBillingLimitReached(): bool
+    {
+        return $this->status === 409 && $this->error === 'billing_limit_reached';
+    }
+
     /**
      * The ID service could not be reached (network error, timeout) or failed (5xx): retry later.
      */

src/Id/Exceptions/CollectionException.php

@@ -2,10 +2,10 @@
 
 namespace Anikeen\Id\Exceptions;
 
-use Anikeen\Id\Result;
+/**
-use Exception;
+ * A list request failed. Like ApiException it carries the HTTP status (also as getCode()) and
-
+ * Anikeen ID's error code.
-class CollectionException extends Exception
+ */
+class CollectionException extends ApiException
 {
-
+}
-}

src/Id/Exceptions/ConfirmationRequiredException.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Anikeen\Id\Exceptions;
+
+use Throwable;
+
+/**
+ * Thrown when a third-party app tries to check out an order or subscription itself: the user has
+ * to confirm it on Anikeen ID. Send them to the confirmation URL instead.
+ */
+class ConfirmationRequiredException extends ResourceException
+{
+    public function __construct(string $message, int $code, public readonly ?string $confirmationUrl = null, ?Throwable $previous = null)
+    {
+        parent::__construct($message, $code, $previous);
+    }
+}

src/Id/Exceptions/PreconditionFailedException.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Anikeen\Id\Exceptions;
+
+/**
+ * A conditional write failed (412): the stored version wasn't the one sent with `If-Match`
+ * ("preference_version_mismatch"), or the key was already set and the write was create-only
+ * ("preference_exists"). Reload, merge and retry with currentVersion().
+ */
+class PreconditionFailedException extends ApiException
+{
+    /**
+     * The version stored now, null when the key isn't set (or Anikeen ID didn't send one).
+     */
+    public function currentVersion(): ?int
+    {
+        $version = $this->body()->current_version ?? null;
+
+        return is_numeric($version) ? (int) $version : null;
+    }
+}

src/Id/Exceptions/SignatureVerificationException.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Anikeen\Id\Exceptions;
+
+use Exception;
+
+/**
+ * The webhook request was not signed by Anikeen ID with your endpoint's secret, or is too old.
+ */
+class SignatureVerificationException extends Exception
+{
+    //
+}

src/Id/HasAnikeenTokens.php

@@ -26,9 +26,23 @@ trait HasAnikeenTokens
      */
     public function anikeenTokenCan(string $scope): bool
     {
-        $scopes = $this->accessToken ? $this->accessToken->scopes : [];
+        $scopes = (array) ($this->accessToken->scopes ?? []);
 
-        return in_array('*', $scopes) || in_array($scope, $this->accessToken->scopes);
+        return in_array('*', $scopes, true) || in_array($scope, $scopes, true);
+    }
+
+    /**
+     * Determine if the current API token has any of the given scopes.
+     */
+    public function anikeenTokenCanAny(array $scopes): bool
+    {
+        foreach ($scopes as $scope) {
+            if ($this->anikeenTokenCan($scope)) {
+                return true;
+            }
+        }
+
+        return false;
     }
 
     /**

src/Id/Helpers/JwtParser.php

@@ -7,32 +7,74 @@ use Firebase\JWT\JWT;
 use Firebase\JWT\Key;
 use Illuminate\Auth\AuthenticationException;
 use Illuminate\Http\Request;
+use RuntimeException;
 use stdClass;
 use Throwable;
 
+/**
+ * Verifies access tokens issued by Anikeen ID (Passport, RS256): signature against
+ * Anikeen ID's public key plus the time claims (exp, nbf, iat; 60 seconds leeway).
+ *
+ * The key is `services.anikeen.public_key` (PEM, "\n" escapes allowed) or the file at
+ * `services.anikeen.public_key_path`, else the key shipped with this package for the
+ * configured mode (production / staging). It is read once per process.
+ */
 class JwtParser
 {
+    /**
+     * Public keys already read, by source.
+     *
+     * @var array<string, string>
+     */
+    private static array $keys = [];
+
     /**
      * @throws AuthenticationException
      */
     public function decode(Request $request): stdClass
     {
+        return $this->decodeToken((string) $request->bearerToken());
+    }
+
+    /**
+     * @throws AuthenticationException
+     */
+    public function decodeToken(string $token): stdClass
+    {
+        if ($token === '') {
+            throw new AuthenticationException('No access token given.');
+        }
+
         JWT::$leeway = 60;
 
+        // outside the try: a missing key is a configuration error, not an invalid token
+        $key = new Key($this->getOauthPublicKey(), 'RS256');
+
         try {
-            return JWT::decode(
+            return JWT::decode($token, $key);
-                $request->bearerToken(),
+        } catch (Throwable) {
-                new Key($this->getOauthPublicKey(), 'RS256')
+            throw new AuthenticationException('The access token is invalid or expired.');
-            );
-        } catch (Throwable $exception) {
-            throw (new AuthenticationException());
         }
     }
 
-    private function getOauthPublicKey(): bool|string
+    /**
+     * Forget the keys read so far (e.g. after changing the configuration in tests).
+     */
+    public static function flushKeys(): void
     {
-        return AnikeenId::getMode() === 'staging'
+        self::$keys = [];
-            ? file_get_contents(dirname(__DIR__, 3) . '/oauth-public.staging.key')
+    }
-            : file_get_contents(dirname(__DIR__, 3) . '/oauth-public.key');
+
+    protected function getOauthPublicKey(): string
+    {
+        if ($key = config('services.anikeen.public_key')) {
+            return self::$keys['config:' . md5($key)] ??= str_replace('\\n', "\n", $key);
+        }
+
+        $path = config('services.anikeen.public_key_path') ?: (AnikeenId::getMode() === 'staging'
+            ? dirname(__DIR__, 3) . '/oauth-public.staging.key'
+            : dirname(__DIR__, 3) . '/oauth-public.key');
+
+        return self::$keys['file:' . $path] ??= (is_readable($path) ? (string) file_get_contents($path) : throw new RuntimeException("Anikeen ID public key [$path] is not readable."));
     }
 }

src/Id/Http/Middleware/CheckForAnyScope.php

@@ -6,7 +6,7 @@ use Anikeen\Id\Exceptions\MissingScopeException;
 use Closure;
 use Illuminate\Auth\AuthenticationException;
 use Illuminate\Http\Request;
-use Illuminate\Http\Response;
+use Symfony\Component\HttpFoundation\Response;
 
 class CheckForAnyScope extends UseParameters
 {
@@ -17,7 +17,7 @@ class CheckForAnyScope extends UseParameters
      */
     public function handle(Request $request, Closure $next, ...$scopes): Response
     {
-        if (!$request->user() || !$request->user()->anikeenToken()) {
+        if (!$request->user() || !method_exists($request->user(), 'anikeenToken') || !$request->user()->anikeenToken()) {
             throw new AuthenticationException;
         }
 

src/Id/Http/Middleware/CheckScopes.php

@@ -6,7 +6,7 @@ use Anikeen\Id\Exceptions\MissingScopeException;
 use Closure;
 use Illuminate\Auth\AuthenticationException;
 use Illuminate\Http\Request;
-use Illuminate\Http\Response;
+use Symfony\Component\HttpFoundation\Response;
 
 class CheckScopes extends UseParameters
 {
@@ -17,7 +17,7 @@ class CheckScopes extends UseParameters
      */
     public function handle(Request $request, Closure $next, ...$scopes): Response
     {
-        if (!$request->user() || !$request->user()->anikeenToken()) {
+        if (!$request->user() || !method_exists($request->user(), 'anikeenToken') || !$request->user()->anikeenToken()) {
             throw new AuthenticationException;
         }
 

src/Id/Providers/AnikeenIdServiceProvider.php

@@ -8,8 +8,11 @@ use Anikeen\Id\Auth\UserProvider;
 use Anikeen\Id\Contracts;
 use Anikeen\Id\Helpers\JwtParser;
 use Anikeen\Id\Repository;
+use Illuminate\Auth\AuthManager;
 use Illuminate\Auth\RequestGuard;
-use Illuminate\Support\Facades\Auth;
+use Illuminate\Contracts\Foundation\Application;
+use Illuminate\Http\Request;
+use InvalidArgumentException;
 use Illuminate\Support\ServiceProvider;
 
 class AnikeenIdServiceProvider extends ServiceProvider
@@ -38,15 +41,28 @@ class AnikeenIdServiceProvider extends ServiceProvider
     }
 
     /**
-     * Register the token guard.
+     * Register the `anikeen` guard driver and user provider.
+     *
+     * Laravel binds non-static extend() closures to the AuthManager, so these closures are
+     * static and use nothing but their arguments.
      */
     protected function registerGuard(): void
     {
-        Auth::resolved(function ($auth) {
+        $this->callAfterResolving('auth', static function (AuthManager $auth): void {
-            $auth->extend('anikeen', function ($app, $name, array $config) {
+            $auth->provider('anikeen', static fn (Application $app, array $config) => new AnikeenIdUserProvider(
-                return tap($this->makeGuard($config), function ($guard) {
+                $app->make(AnikeenId::class),
-                    $this->app->refresh('request', $guard, 'setRequest');
+                $app->make('request'),
-                });
+                $config['model'] ?? $app['config']->get('auth.providers.users.model'),
+                $config['fields'] ?? [],
+                $config['column'] ?? null,
+            ));
+
+            $auth->extend('anikeen', static function (Application $app, string $name, array $config): RequestGuard {
+                $guard = AnikeenIdServiceProvider::makeGuard($app, $config);
+
+                $app->refresh('request', $guard, 'setRequest');
+
+                return $guard;
             });
         });
     }
@@ -54,15 +70,20 @@ class AnikeenIdServiceProvider extends ServiceProvider
     /**
      * Make an instance of the token guard.
      */
-    protected function makeGuard(array $config): RequestGuard
+    public static function makeGuard(Application $app, array $config): RequestGuard
     {
-        return new RequestGuard(function ($request) use ($config) {
+        $providerName = $config['provider'] ?? $app['config']->get('auth.defaults.provider', 'users');
+        $provider = $app['auth']->createUserProvider($providerName)
+            ?? throw new InvalidArgumentException("Authentication user provider [$providerName] is not configured.");
+        $providerConfig = $app['config']->get("auth.providers.$providerName", []);
+
+        return new RequestGuard(static function (Request $request) use ($app, $provider, $providerName, $providerConfig, $config) {
             return (new TokenGuard(
-                new UserProvider(Auth::createUserProvider($config['provider']), $config['provider']),
+                new UserProvider($provider, $providerName, $config['column'] ?? $providerConfig['column'] ?? null),
-                $this->app->make('encrypter'),
+                $app->make('encrypter'),
-                $this->app->make(JwtParser::class)
+                $app->make(JwtParser::class)
             ))->user($request);
-        }, $this->app['request']);
+        }, $app['request'], $provider);
     }
 
     /**

src/Id/Providers/AnikeenIdUserProvider.php

@@ -18,7 +18,8 @@ class AnikeenIdUserProvider implements UserProvider
         private AnikeenId $anikeenId,
         private Request   $request,
         private string    $model,
-        private array     $fields = []
+        private array     $fields = [],
+        private ?string   $column = null,
     ) {
         $this->accessTokenField = AnikeenId::getAccessTokenField();
     }
@@ -97,6 +98,17 @@ class AnikeenIdUserProvider implements UserProvider
             ->first();
     }
 
+    /**
+     * Find the user of an Anikeen ID (the `sub` of an access token) by the provider's `column`,
+     * else `services.anikeen.user_id_column`, else AnikeenId::getUserIdField() (`anikeen_id`).
+     */
+    public function retrieveByAnikeenId(string $anikeenId): ?Authenticatable
+    {
+        $column = $this->column ?: (config('services.anikeen.user_id_column') ?: AnikeenId::getUserIdField());
+
+        return $this->newModelQuery()->where($column, $anikeenId)->first();
+    }
+
     /**
      * {@inheritDoc}
      */

src/Id/Resources/AppCharge.php

@@ -0,0 +1,139 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use DateTimeImmutable;
+use JsonSerializable;
+
+/**
+ * A charge a trusted app booked onto a user's open monthly bill, see
+ * AnikeenId::createChargeForUser(). Amounts are decimal strings (`unit_price` with six decimals,
+ * the others with two).
+ *
+ * @property string $object "charge"
+ * @property string $id
+ * @property string $user_id
+ * @property string $status open (its bill is open), billed (the bill was closed) or voided
+ * @property string $idempotency_key
+ * @property string $name the line on the bill
+ * @property ?string $description
+ * @property string $type digital, physical or physical-reduced (the VAT treatment)
+ * @property int $quantity
+ * @property string $unit "piece"
+ * @property string $unit_price net per piece
+ * @property string $net_amount
+ * @property string $gross_amount what the charge added to the bill, VAT included
+ * @property string $currency_iso
+ * @property ?string $group
+ * @property string $occurred_at the line's service date (ISO 8601)
+ * @property ?string $reference the app's own id
+ * @property object $metadata the app's own data (string values)
+ * @property ?string $order_id the monthly bill (order) the line is on; follows the line when a rollover moves it
+ * @property ?string $voided_at
+ * @property ?string $void_reason
+ * @property string $created_at
+ */
+class AppCharge implements JsonSerializable
+{
+    public const STATUS_OPEN = 'open';
+
+    public const STATUS_BILLED = 'billed';
+
+    public const STATUS_VOIDED = 'voided';
+
+    public function __construct(protected object $data)
+    {
+    }
+
+    public function __get(string $name): mixed
+    {
+        return $this->data->{$name} ?? null;
+    }
+
+    public function __isset(string $name): bool
+    {
+        return isset($this->data->{$name});
+    }
+
+    public function id(): string
+    {
+        return $this->data->id;
+    }
+
+    /**
+     * open, billed or voided (the STATUS_* constants).
+     */
+    public function status(): string
+    {
+        return $this->data->status;
+    }
+
+    /**
+     * Its bill is still open: the charge can be voided.
+     */
+    public function isOpen(): bool
+    {
+        return $this->status() === self::STATUS_OPEN;
+    }
+
+    /**
+     * Its bill was closed (paid, waiting for payment or cancelled): only a refund of the order by
+     * Anikeen credits it.
+     */
+    public function isBilled(): bool
+    {
+        return $this->status() === self::STATUS_BILLED;
+    }
+
+    public function isVoided(): bool
+    {
+        return $this->status() === self::STATUS_VOIDED;
+    }
+
+    /**
+     * Net, e.g. "8.00".
+     */
+    public function netAmount(): string
+    {
+        return $this->data->net_amount;
+    }
+
+    /**
+     * Gross, what the charge added to the bill, e.g. "9.52".
+     */
+    public function grossAmount(): string
+    {
+        return $this->data->gross_amount;
+    }
+
+    /**
+     * The monthly bill (order) the charge is on, null once its line is gone (voided).
+     */
+    public function orderId(): ?string
+    {
+        return $this->data->order_id ?? null;
+    }
+
+    /**
+     * @return array<string, string>
+     */
+    public function metadata(): array
+    {
+        return (array) ($this->data->metadata ?? []);
+    }
+
+    public function occurredAt(): ?DateTimeImmutable
+    {
+        return isset($this->data->occurred_at) ? new DateTimeImmutable($this->data->occurred_at) : null;
+    }
+
+    public function toArray(): array
+    {
+        return (array) $this->data;
+    }
+
+    public function jsonSerialize(): array
+    {
+        return $this->toArray();
+    }
+}

src/Id/Resources/AppCheckoutSession.php

@@ -0,0 +1,97 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use Anikeen\Id\Concerns\IsCheckoutSession;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Support\AppRequest;
+use JsonSerializable;
+
+/**
+ * A checkout session created with the app's own token, see AppCheckoutSessions.
+ *
+ * @property string $id
+ * @property string $user_id
+ * @property ?string $oauth_client_id
+ * @property string $status open, completed, cancelled or expired
+ * @property ?string $return_url
+ * @property ?object $metadata
+ * @property ?string $confirmation_url
+ * @property list<string> $subscription_ids
+ * @property list<object> $subscriptions
+ * @property ?string $expires_at
+ * @property ?string $completed_at
+ * @property ?string $cancelled_at
+ * @property ?string $created_at
+ */
+class AppCheckoutSession implements JsonSerializable
+{
+    use IsCheckoutSession;
+
+    public const STATUS_OPEN = 'open';
+    public const STATUS_COMPLETED = 'completed';
+    public const STATUS_CANCELLED = 'cancelled';
+    public const STATUS_EXPIRED = 'expired';
+
+    public function __construct(protected object $data)
+    {
+    }
+
+    public function __get(string $name): mixed
+    {
+        return $this->data->{$name} ?? null;
+    }
+
+    public function __isset(string $name): bool
+    {
+        return isset($this->data->{$name});
+    }
+
+    /**
+     * The session's subscriptions (drafts until the user confirms).
+     *
+     * @return list<AppSubscription>
+     */
+    public function subscriptions(): array
+    {
+        return array_map(fn (object $subscription) => new AppSubscription($subscription), array_values((array) ($this->data->subscriptions ?? [])));
+    }
+
+    /**
+     * Withdraw an open session (e.g. the cart changed): it and its drafts are cancelled.
+     *
+     * @throws ApiException 409 "checkout_session_completed", "checkout_session_cancelled", "checkout_session_expired"
+     */
+    public function cancel(): self
+    {
+        return $this->send('POST', '/cancel');
+    }
+
+    /**
+     * @throws ApiException
+     */
+    public function refresh(): self
+    {
+        return $this->send('GET', '');
+    }
+
+    public function toArray(): array
+    {
+        return (array) $this->data;
+    }
+
+    public function jsonSerialize(): array
+    {
+        return $this->toArray();
+    }
+
+    /**
+     * @throws ApiException
+     */
+    private function send(string $method, string $action): self
+    {
+        $this->data = AppRequest::send($method, sprintf('v1/client/checkout-sessions/%s%s', $this->id, $action))->data;
+
+        return $this;
+    }
+}

src/Id/Resources/AppCheckoutSessions.php

@@ -0,0 +1,91 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use Anikeen\Id\Contracts\Billable;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Support\AppRequest;
+use Illuminate\Database\Eloquent\Model;
+use InvalidArgumentException;
+
+/**
+ * Checkout sessions created with the app's own token (trusted apps, scope `subscriptions:client`):
+ * several subscriptions of one user that the user confirms together on Anikeen ID, instead of the
+ * app checking them out itself. For one user ($user->appCheckoutSessions()) or, to look sessions
+ * up e.g. from a webhook, for all users (app(AnikeenId::class)->appCheckoutSessions()).
+ * Nothing is requested until a method is called.
+ */
+class AppCheckoutSessions
+{
+    public function __construct(protected Billable|Model|null $billable = null)
+    {
+    }
+
+    /**
+     * Open a checkout session with new subscriptions (their attributes, like
+     * AppSubscriptions::create()) and/or existing drafts of the app (`['id' => …]`).
+     *
+     * @param array{
+     *     subscriptions: list<array{id: string}|array{
+     *         group?: null|string,
+     *         name: string,
+     *         description?: null|string,
+     *         unit: string,
+     *         price: float|string,
+     *         monthly_cap?: null|float|string,
+     *         predecessor_id?: null|string,
+     *         vat_rate?: float,
+     *         payload?: null|array,
+     *         ends_at?: null|string,
+     *         trial_days?: null|int,
+     *         trial_ends_at?: null|string,
+     *         trial_once?: bool,
+     *         trial_payment_method?: null|string,
+     *         discount?: null|array{label: string, percent_off?: float|string, amount_off?: float|string, duration: string, duration_in_periods?: int}
+     *     }>,
+     *     return_url?: null|string,
+     *     metadata?: null|array,
+     *     idempotency_key?: null|string,
+     *     user_id?: string
+     * } $attributes return_url must share scheme, host and port with one of the app's redirect
+     *               URIs; the user comes back to it with `status` and `checkout_session`. A
+     *               repeated idempotency_key returns the first session instead of a new one.
+     *               trial_days / trial_ends_at give a subscription a free trial from the user's
+     *               confirmation on; trial_once is allowed on one subscription per group.
+     *               trial_payment_method `optional`: the session can be confirmed without a
+     *               payment method only if all of its subscriptions are such trials.
+     *               discount: see AppSubscriptions::create(); the confirmation page shows it.
+     *
+     * @throws ApiException 422 validation (e.g. return_url), 409 "idempotency_key_conflict"
+     */
+    public function create(array $attributes): AppCheckoutSession
+    {
+        if ($this->billable) {
+            $attributes['user_id'] = (new AppSubscriptions($this->billable))->userId();
+        } elseif (empty($attributes['user_id'])) {
+            throw new InvalidArgumentException('A checkout session needs a user: use $user->appCheckoutSessions() or pass user_id.');
+        }
+
+        return new AppCheckoutSession(AppRequest::send('POST', 'v1/client/checkout-sessions', $attributes)->data);
+    }
+
+    /**
+     * A session of the app; null when it doesn't exist (or belongs to another user).
+     *
+     * @throws ApiException
+     */
+    public function find(string $id): ?AppCheckoutSession
+    {
+        try {
+            $session = new AppCheckoutSession(AppRequest::send('GET', sprintf('v1/client/checkout-sessions/%s', $id))->data);
+        } catch (ApiException $e) {
+            if ($e->isNotFound()) {
+                return null;
+            }
+
+            throw $e;
+        }
+
+        return !$this->billable || $session->user_id === (new AppSubscriptions($this->billable))->userId() ? $session : null;
+    }
+}

src/Id/Resources/AppOrders.php

@@ -13,9 +13,22 @@ use Illuminate\Database\Eloquent\Model;
  * scope orders:client) - of one user ($user->appOrders()) or of all users
  * (app(AnikeenId::class)->appOrders()). Nothing is requested until a method is called.
  *
- * Each order is an object with id, user_id, group, status (processing|pending|completed|cancelled),
+ * Each order is an object with id, user_id, oauth_client_id (the app that bills it: collective
- * is_collective, net_total, vat_total, gross_total, currency_iso, created_at, paid_at,
+ * orders are kept per app, even for the same group; null on legacy orders that billed several
- * payment_attempts, next_payment_attempt_at and last_payment_error ({code, message} or null).
+ * apps), group, metadata, status (processing|pending|completed|cancelled), is_collective,
+ * net_total, vat_total, gross_total, currency_iso, created_at, paid_at, payment_attempts,
+ * next_payment_attempt_at, last_payment_error ({code, message} or null), and
+ *
+ * - items: the order's lines of the app's subscriptions (all lines, except on legacy orders that
+ *   also billed other apps), each {id, name, description, type, image_url, units, unit,
+ *   price, vat_rate, subscription_id, meter, monthly_cap, discount, period_start, period_end,
+ *   net_amount, vat_amount, gross_amount}. period_end is exclusive (the start of the next
+ *   period); both are null for lines without a period. discount ({label, percent_off,
+ *   amount_off}) marks the negative line of a subscription's discount, else null. The net amount
+ *   a subscription was billed is the sum of net_amount of its lines.
+ * - invoice: null until the order is paid, then {id, number, type, status (pending while the PDF
+ *   is being rendered, then completed), service_period_from, service_period_to, created_at,
+ *   pdf_url}; see invoicePdf().
  */
 class AppOrders
 {
@@ -81,6 +94,22 @@ class AppOrders
         return !$this->billable || $order->user_id === $this->userId() ? $order : null;
     }
 
+    /**
+     * The PDF of an order's invoice (binary string, with the embedded e-invoice), the same as its
+     * `invoice.pdf_url` with the app's token.
+     *
+     * @throws ApiException 404 "order_not_found", 404 "invoice_not_found" (not paid yet),
+     *                      409 "invoice_not_ready" (still being rendered, try again later)
+     */
+    public function invoicePdf(string $orderId): string
+    {
+        if ($this->billable && !$this->find($orderId)) {
+            throw new ApiException('Order not found.', 404, 'order_not_found');
+        }
+
+        return (string) AppRequest::send('GET', sprintf('v1/client/orders/%s/invoice', $orderId))->response()?->getBody();
+    }
+
     private function userId(): string
     {
         return (new AppSubscriptions($this->billable))->userId();

src/Id/Resources/AppSubscription.php

@@ -2,8 +2,11 @@
 
 namespace Anikeen\Id\Resources;
 
+use Anikeen\Id\Concerns\HasSubscriptionStatus;
 use Anikeen\Id\Exceptions\ApiException;
 use Anikeen\Id\Support\AppRequest;
+use DateTimeInterface;
+use InvalidArgumentException;
 use JsonSerializable;
 
 /**
@@ -16,11 +19,19 @@ use JsonSerializable;
  * @property ?string $description
  * @property string $unit
  * @property float $price
+ * @property ?float $monthly_cap net, at most this per calendar month (hour and day units)
+ * @property ?float $expected_monthly_price gross estimate for a month (720 hours, at most the monthly cap)
+ * @property ?string $predecessor_id the subscription this one replaced (a resize); they share the monthly cap
  * @property ?float $vat_rate
  * @property bool $active
  * @property bool $autorenew
  * @property bool $cancelled
- * @property ?string $status "active" or "inactive"
+ * @property ?string $status draft, trial, active, paused, cancelling, expired or cancelled, see status()
+ * @property ?string $cancels_at when a scheduled cancellation takes effect
+ * @property ?string $trial_ends_at
+ * @property ?string $trial_payment_method required or optional with a trial (TrialPaymentMethod), null without
+ * @property ?string $cancellation_reason why the billing cancelled it (CancellationReason), null otherwise
+ * @property ?object $discount {label, percent_off, amount_off, duration, duration_in_periods, periods_remaining}; periods_remaining is null for `forever`, 0 once it ended
  * @property ?string $starts_at
  * @property ?string $ends_at
  * @property ?string $accounting_at
@@ -28,9 +39,19 @@ use JsonSerializable;
  * @property int $failed_renewal_retries
  * @property ?array $payload
  * @property ?string $idempotency_key
+ * @property ?string $checkout_session_id the checkout session the user confirms it in, if any
+ * @property ?object $scheduled_change {applies_at, name, description, unit, price, discount, created_at}: a change() for the period end
  */
 class AppSubscription implements JsonSerializable
 {
+    use HasSubscriptionStatus;
+
+    /** change(): prorated, right away. */
+    public const APPLY_NOW = 'now';
+
+    /** change(): from the next period on (scheduled_change until then). */
+    public const APPLY_PERIOD_END = 'period_end';
+
     public function __construct(protected object $data)
     {
     }
@@ -46,7 +67,10 @@ class AppSubscription implements JsonSerializable
     }
 
     /**
-     * Change a subscription that wasn't checked out yet.
+     * Change a subscription (send only what changes). Before checkout everything can change;
+     * afterwards only the description, which names what the customer pays for and is shown
+     * on their bills, e.g. `$subscription->update(['description' => 'web-01.example.com'])`.
+     * Prices of running subscriptions change with change().
      *
      * @throws ApiException
      */
@@ -55,14 +79,97 @@ class AppSubscription implements JsonSerializable
         return $this->send('PUT', '', $attributes);
     }
 
+    /**
+     * Change a running subscription (send only what changes), like a plan change:
+     *
+     * - `apply: now`: prorated – the unused rest of the current period is credited at the rate it
+     *   was billed at and charged at the new price on the user's open bill. A new unit starts a
+     *   new, fully billed period now. A downgrade whose credit exceeds the open bill is refused
+     *   (409 "credit_exceeds_bill"): schedule it for the period end instead.
+     * - `apply: period_end`: nothing changes now; the subscription has `scheduled_change` and the
+     *   next period is billed at the new values. A new scheduled change replaces the previous one.
+     *
+     * During a free trial nothing was billed, so both just change what the trial ends in.
+     * Webhook `subscription.updated` (with `data.previous_attributes`) when the change takes effect.
+     *
+     * @param array{
+     *     apply: string,
+     *     price?: float|string,
+     *     unit?: string,
+     *     name?: string,
+     *     description?: null|string,
+     *     discount?: null|array{label: string, percent_off?: float|string, amount_off?: float|string, duration: string, duration_in_periods?: int}
+     * } $attributes apply: self::APPLY_NOW or self::APPLY_PERIOD_END.
+     *               unit: a recurring unit (hour, day, week, month, year).
+     *               discount: replaces the discount from the next billed period on, null ends it;
+     *               required with a new unit when the current one counts in periods or is an
+     *               amount_off. Subscriptions with a monthly cap change only at the period end.
+     *
+     * @throws ApiException 409 "not_changeable" (not running: draft, paused, cancelling, …),
+     *                      "proration_not_possible", "credit_exceeds_bill",
+     *                      "billing_address_missing"; 422 validation
+     */
+    public function change(array $attributes): self
+    {
+        return $this->send('PUT', '/change', $attributes);
+    }
+
+    /**
+     * Drop the change scheduled for the period end (nothing happens without one).
+     *
+     * @throws ApiException
+     */
+    public function cancelScheduledChange(): self
+    {
+        return $this->send('DELETE', '/change');
+    }
+
     /**
      * Activate the subscription and bill its first period.
      *
-     * @throws ApiException 409 "already_active", "billing_address_missing", …
+     * $startsAt (in the past) books a service that is already running, e.g. a domain registered
+     * earlier: the first period runs from $startsAt, is billed now and renews when it ends.
+     *
+     * A $startsAt older than one period is refused ("period_already_ended") unless
+     * $billElapsedPeriods is set: then the periods that have already ended are billed too, together
+     * with the running one, as long as they come to at most $maxNetAmount (net, up to two
+     * decimals) and $startsAt lies within the maximum age Anikeen ID accepts (about three years).
+     * The lines land on the current month's collective order, which is charged on the 1st of the
+     * next month. $billElapsedPeriods needs both $startsAt and $maxNetAmount.
+     *
+     * @throws ApiException 409 "already_active", "billing_address_missing", "period_already_ended",
+     *     "elapsed_periods_not_allowed" (the elapsed periods can't be billed for this subscription),
+     *     "elapsed_amount_exceeded" (they come to more than $maxNetAmount; the response body has
+     *     the booked `net_amount`), …; 422 invalid input (e.g. a start older than the maximum age)
+     * @throws InvalidArgumentException $billElapsedPeriods without $startsAt or $maxNetAmount
      */
-    public function checkout(): self
+    public function checkout(
-    {
+        DateTimeInterface|string|null $startsAt = null,
-        return $this->send('PUT', '/checkout');
+        bool $billElapsedPeriods = false,
+        float|string|null $maxNetAmount = null,
+    ): self {
+        if ($startsAt instanceof DateTimeInterface) {
+            $startsAt = $startsAt->format(DateTimeInterface::ATOM);
+        }
+
+        if (!$billElapsedPeriods) {
+            return $this->send('PUT', '/checkout', $startsAt === null ? null : ['starts_at' => $startsAt]);
+        }
+
+        if ($startsAt === null || $startsAt === '') {
+            throw new InvalidArgumentException('Billing elapsed periods needs a start date ($startsAt).');
+        }
+
+        if ($maxNetAmount === null || $maxNetAmount === '') {
+            throw new InvalidArgumentException('Billing elapsed periods needs a maximum net amount ($maxNetAmount).');
+        }
+
+        return $this->send('PUT', '/checkout', [
+            'starts_at' => $startsAt,
+            'bill_elapsed_periods' => true,
+            // floats from calculations may carry binary noise (e.g. 59.970000000000006)
+            'max_net_amount' => is_float($maxNetAmount) ? round($maxNetAmount, 2) : $maxNetAmount,
+        ]);
     }
 
     /**

src/Id/Resources/AppSubscriptions.php

@@ -44,16 +44,38 @@ class AppSubscriptions
      *     description?: null|string,
      *     unit: string,
      *     price: float|string,
+     *     monthly_cap?: null|float|string,
+     *     predecessor_id?: null|string,
      *     vat_rate?: float,
      *     payload?: null|array,
      *     ends_at?: null|string,
-     *     webhook_url?: null|string,
+     *     trial_days?: null|int,
-     *     webhook_secret?: null|string,
+     *     trial_ends_at?: null|string,
+     *     trial_once?: bool,
+     *     trial_payment_method?: null|string,
+     *     discount?: null|array{label: string, percent_off?: float|string, amount_off?: float|string, duration: string, duration_in_periods?: int},
      *     idempotency_key?: null|string
      * } $attributes With an idempotency_key (max. 191 characters), a retried call returns the
      *               subscription created by the first one instead of a duplicate.
+     *               monthly_cap: net, at most this per calendar month (hour and day units only,
+     *               at most 2 decimals, not below price; null = no cap).
+     *               predecessor_id: the subscription this one replaces (a resize; same user and
+     *               app, checked out, not cancelled): both share the monthly cap within a month.
+     *               trial_days: a free trial of 1–365 days from the checkout on (status `trial`,
+     *               nothing billed; the first period is billed when it ends), or
+     *               trial_ends_at: a fixed end of the trial (ISO 8601, in the future), not both.
+     *               trial_once: refuse the trial if the user already had one with the app in the
+     *               same group (422 here, 409 "trial_already_used" on checkout).
+     *               trial_payment_method: TrialPaymentMethod::REQUIRED (default) or ::OPTIONAL,
+     *               only with a trial: with `optional` the user may confirm it without a payment
+     *               method, and without one at the trial's end it is cancelled instead of billed.
+     *               discount: e.g. a coupon, as a negative line next to each billed period:
+     *               label (shown to the user, max. 100 characters), percent_off (0.01–100) or
+     *               amount_off (net per period, at most the price), duration `once` (the first
+     *               billed period), `repeating` (duration_in_periods billed periods) or
+     *               `forever`. Not combinable with a monthly_cap.
      *
-     * @throws ApiException
+     * @throws ApiException 422 validation, 409 "idempotency_key_conflict", …
      */
     public function create(array $attributes): AppSubscription
     {

src/Id/Resources/BaseCollection.php

@@ -7,6 +7,7 @@ use Anikeen\Id\Exceptions\CollectionException;
 use Anikeen\Id\Helpers\Paginator;
 use Anikeen\Id\Result;
 use Closure;
+use GuzzleHttp\Exception\GuzzleException;
 use GuzzleHttp\Psr7\Response;
 use JsonSerializable;
 use Throwable;
@@ -34,10 +35,15 @@ abstract class BaseCollection implements JsonSerializable
      */
     protected function __construct(callable $callable)
     {
-        $this->result = $callable();
+        try {
+            $this->result = $callable();
+        } catch (GuzzleException $e) {
+            // no response at all (connection refused, timeout)
+            throw CollectionException::unreachable($e);
+        }
 
         if (!$this->result->success()) {
-            throw new CollectionException(sprintf('%s for collection [%s]', rtrim($this->result->data->message, '.'), get_called_class()), $this->result->response->getStatusCode());
+            throw CollectionException::fromResult($this->result);
         }
     }
 

src/Id/Resources/BaseResource.php

@@ -2,8 +2,10 @@
 
 namespace Anikeen\Id\Resources;
 
-use Anikeen\Id\Exceptions\ResourceException;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Exceptions\ConfirmationRequiredException;
 use Anikeen\Id\Result;
+use GuzzleHttp\Exception\GuzzleException;
 use JsonSerializable;
 
 #[\AllowDynamicProperties]
@@ -12,14 +14,28 @@ abstract class BaseResource implements JsonSerializable
     public Result $result;
 
     /**
-     * @throws ResourceException
+     * @throws ApiException the request failed (status, error code; a ResourceException)
+     * @throws ConfirmationRequiredException the user has to confirm it on Anikeen ID
      */
     public function __construct(callable $callable)
     {
-        $this->result = $callable();
+        try {
+            $this->result = $callable();
+        } catch (GuzzleException $e) {
+            // no response at all (connection refused, timeout)
+            throw ApiException::unreachable($e);
+        }
 
         if (!$this->result->success()) {
-            throw new ResourceException(sprintf('%s for resource [%s]', rtrim($this->result->data->message, '.'), get_called_class()), $this->result->response->getStatusCode());
+            if (($this->result->data->error ?? null) === 'confirmation_required') {
+                throw new ConfirmationRequiredException(
+                    $this->result->data->message ?? 'The user has to confirm this on Anikeen ID.',
+                    $this->result->response->getStatusCode(),
+                    $this->result->data->confirmation_url ?? null,
+                );
+            }
+
+            throw ApiException::fromResult($this->result);
         }
 
         foreach ($this->result->data as $key => $value) {

src/Id/Resources/BillingLimit.php

@@ -0,0 +1,186 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use DateTimeImmutable;
+use JsonSerializable;
+
+/**
+ * A user's monthly billing limit: one gross limit for their whole open monthly bill across all
+ * Anikeen services, see AnikeenId::billingLimitForUser() and the `billing_limit` key of
+ * billingOverview(). Amounts are decimal strings with two decimals.
+ *
+ * Without a limit `limit`, `remaining` and `remaining_net` are null; for an app `used` is null
+ * too (an app sees the user's whole open bill only while they have set a limit). `used_by_app`
+ * (the open bills of your app) is there only when an app reads the limit.
+ *
+ * @property string $object "billing_limit"
+ * @property string $user_id
+ * @property string $currency "EUR"
+ * @property string $basis "gross"
+ * @property ?string $limit
+ * @property ?string $used the user's open monthly bills across all Anikeen services
+ * @property ?string $used_by_app the open monthly bills of your app (app reads only)
+ * @property ?string $remaining max(0, limit − used)
+ * @property ?string $remaining_net remaining at the user's VAT rate, rounded down (a hint)
+ * @property int|float|null $vat_rate null without a billing address
+ * @property bool $reached used >= limit: start no new paid service
+ * @property string $resets_at when this month's bills are closed (ISO 8601)
+ * @property int $version only goes up; keep the highest seen (also in the billing_limit.* webhooks)
+ */
+class BillingLimit implements JsonSerializable
+{
+    public function __construct(protected object $data)
+    {
+    }
+
+    public function __get(string $name): mixed
+    {
+        return $this->data->{$name} ?? null;
+    }
+
+    public function __isset(string $name): bool
+    {
+        return isset($this->data->{$name});
+    }
+
+    /**
+     * The user has set a limit (`0.00` is one too: no new charges at all).
+     */
+    public function hasLimit(): bool
+    {
+        return $this->limit() !== null;
+    }
+
+    /**
+     * Gross, null without a limit.
+     */
+    public function limit(): ?string
+    {
+        return $this->data->limit ?? null;
+    }
+
+    /**
+     * The user's open monthly bills across all Anikeen services (gross). Null for an app while the
+     * user has no limit.
+     */
+    public function used(): ?string
+    {
+        return $this->data->used ?? null;
+    }
+
+    /**
+     * The open monthly bills of your app (gross); null outside an app read (billingOverview()).
+     * `used − used_by_app` is what the user spends on their other Anikeen services.
+     */
+    public function usedByApp(): ?string
+    {
+        return $this->data->used_by_app ?? null;
+    }
+
+    /**
+     * Gross room left (never negative), null without a limit.
+     */
+    public function remaining(): ?string
+    {
+        return $this->data->remaining ?? null;
+    }
+
+    /**
+     * The room left as a net amount at the user's VAT rate, rounded down: a hint only (the VAT of
+     * a charge depends on its type). Null without a limit or a billing address.
+     */
+    public function remainingNet(): ?string
+    {
+        return $this->data->remaining_net ?? null;
+    }
+
+    /**
+     * The user's VAT rate in percent (e.g. 19.0), null without a billing address.
+     */
+    public function vatRate(): ?float
+    {
+        return isset($this->data->vat_rate) ? (float) $this->data->vat_rate : null;
+    }
+
+    public function currency(): string
+    {
+        return $this->data->currency ?? 'EUR';
+    }
+
+    /**
+     * The limit is reached (used >= limit): start no new paid service for the user.
+     */
+    public function isReached(): bool
+    {
+        return (bool) ($this->data->reached ?? false);
+    }
+
+    /**
+     * When this month's bills are closed and `used` drops.
+     */
+    public function resetsAt(): ?DateTimeImmutable
+    {
+        return isset($this->data->resets_at) ? new DateTimeImmutable($this->data->resets_at) : null;
+    }
+
+    /**
+     * Only goes up: keep the highest one seen and ignore webhooks with a lower or equal one.
+     */
+    public function version(): int
+    {
+        return (int) ($this->data->version ?? 0);
+    }
+
+    /**
+     * Whether a charge of $gross (gross, e.g. "4.76") would fit as of this read: always without a
+     * limit, else at most `remaining`. Advisory only: it reserves nothing, the binding check is
+     * the booking (409 "billing_limit_reached").
+     */
+    public function allows(string|int|float $gross): bool
+    {
+        if (!$this->hasLimit()) {
+            return true;
+        }
+
+        $remaining = $this->remaining();
+
+        return $remaining !== null && self::compare($gross, $remaining) <= 0;
+    }
+
+    public function toArray(): array
+    {
+        return (array) $this->data;
+    }
+
+    public function jsonSerialize(): array
+    {
+        return $this->toArray();
+    }
+
+    /**
+     * Compares two non-negative decimal amounts exactly (as digit strings, no float rounding);
+     * negative amounts count as zero.
+     */
+    private static function compare(string|int|float $a, string|int|float $b): int
+    {
+        return strcmp(self::micros($a), self::micros($b)) <=> 0;
+    }
+
+    /**
+     * The amount in millionths as a zero-padded digit string of a fixed width.
+     */
+    private static function micros(string|int|float $amount): string
+    {
+        $amount = is_float($amount) ? number_format($amount, 6, '.', '') : trim((string) $amount);
+
+        if (str_starts_with($amount, '-')) {
+            return str_repeat('0', 40);
+        }
+
+        [$whole, $fraction] = array_pad(explode('.', ltrim($amount, '+'), 2), 2, '');
+        $digits = preg_replace('/\D/', '', $whole) . substr(str_pad(preg_replace('/\D/', '', $fraction), 6, '0'), 0, 6);
+
+        return str_pad(ltrim($digits, '0'), 40, '0', STR_PAD_LEFT);
+    }
+}

src/Id/Resources/CheckoutSession.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use Anikeen\Id\Concerns\HasBillable;
+use Anikeen\Id\Concerns\IsCheckoutSession;
+use Throwable;
+
+/**
+ * A checkout session created with the user's access token, see CheckoutSessions.
+ *
+ * @property string $id
+ * @property string $user_id
+ * @property ?string $oauth_client_id
+ * @property string $status open, completed, cancelled or expired
+ * @property ?string $return_url
+ * @property ?object $metadata
+ * @property ?string $confirmation_url
+ * @property list<string> $subscription_ids
+ * @property list<object> $subscriptions
+ * @property ?string $expires_at
+ * @property ?string $completed_at
+ * @property ?string $cancelled_at
+ * @property ?string $created_at
+ */
+class CheckoutSession extends BaseResource
+{
+    use HasBillable;
+    use IsCheckoutSession;
+
+    public const STATUS_OPEN = 'open';
+    public const STATUS_COMPLETED = 'completed';
+    public const STATUS_CANCELLED = 'cancelled';
+    public const STATUS_EXPIRED = 'expired';
+
+    /**
+     * Withdraw an open session: it and its drafts are cancelled.
+     *
+     * @throws Throwable
+     */
+    public function cancel(): self
+    {
+        return (new self(fn () => $this->billable->anikeenId()
+            ->request('POST', sprintf('v1/checkout-sessions/%s/cancel', $this->id))))
+            ->setBillable($this->billable);
+    }
+
+    /**
+     * @throws Throwable
+     */
+    public function refresh(): self
+    {
+        return (new self(fn () => $this->billable->anikeenId()
+            ->request('GET', sprintf('v1/checkout-sessions/%s', $this->id))))
+            ->setBillable($this->billable);
+    }
+}

src/Id/Resources/CheckoutSessions.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use Anikeen\Id\Concerns\HasBillable;
+use Anikeen\Id\Contracts\Billable;
+use Anikeen\Id\Exceptions\ResourceException;
+use Illuminate\Database\Eloquent\Model;
+use Throwable;
+
+/**
+ * Checkout sessions of the signed-in user, with the user's access token (any app): several
+ * subscriptions the user confirms together on Anikeen ID. Nothing is requested until a method is
+ * called.
+ */
+class CheckoutSessions
+{
+    use HasBillable;
+
+    public function __construct(Billable|Model $billable)
+    {
+        $this->billable = $billable;
+    }
+
+    /**
+     * Open a checkout session with new subscriptions and/or existing drafts of the app
+     * (`['id' => …]`); see AppCheckoutSessions::create() for the attributes (no user_id here,
+     * vat_rate only for trusted apps).
+     *
+     * @throws Throwable
+     */
+    public function create(array $attributes): CheckoutSession
+    {
+        return (new CheckoutSession(fn () => $this->billable->anikeenId()
+            ->request('POST', 'v1/checkout-sessions', $attributes)))
+            ->setBillable($this->billable);
+    }
+
+    /**
+     * A session the app created for the user; null when it doesn't exist.
+     *
+     * @throws Throwable
+     */
+    public function find(string $id): ?CheckoutSession
+    {
+        try {
+            return (new CheckoutSession(fn () => $this->billable->anikeenId()
+                ->request('GET', sprintf('v1/checkout-sessions/%s', $id))))
+                ->setBillable($this->billable);
+        } catch (ResourceException $e) {
+            if ($e->getCode() === 404) {
+                return null;
+            }
+
+            throw $e;
+        }
+    }
+}

src/Id/Resources/Order.php

@@ -3,14 +3,24 @@
 namespace Anikeen\Id\Resources;
 
 use Anikeen\Id\Concerns\HasBillable;
+use Anikeen\Id\Concerns\HasConfirmationUrl;
 use Throwable;
 
 /**
  * @property string $id
+ * @property null|string $confirmation_url where the user confirms it (third-party apps, or `confirm`)
+ * @property null|string $oauth_client_id the app that bills the order: the app that created it, or for a monthly
+ *                                        (collective) order the app whose subscriptions it bills; collective orders
+ *                                        are kept per app. null for Anikeen's own (and legacy orders of several apps)
+ * @property null|string $group
+ * @property null|object $metadata the app's own data, returned as is
+ * @property null|string $return_url where the user returns after confirming
+ * @property null|string $expires_at when a draft created with `confirm` is cancelled unless confirmed
  */
 class Order extends BaseResource
 {
     use HasBillable;
+    use HasConfirmationUrl;
 
     /**
      * Update given order from the current user.
@@ -39,21 +49,25 @@ class Order extends BaseResource
      *      },
      *      shipping_address: null|array{
      *           company_name: null|string,
-     *           first_name:  string,
+     *           first_name: string,
      *           last_name: string,
-     *           address: null|string,
+     *           address: string,
-     *           address_2: string,
+     *           address_2: null|string,
      *           house_number: null|string,
      *           city: string,
-     *           state: string,
+     *           state: null|string,
      *           postal_code: string,
      *           country_iso: string,
      *           phone_number: null|string,
      *           email: null|string
-     *      }
+     *      },
+     *      group?: null|string,
+     *      metadata?: null|array
      *  } $attributes The order data:
      *    - billing_address:  Billing address (ISO 3166-1 alpha-2 country code)
-     *    - shipping_address: Shipping address (first name, last name, ISO 3166-1 alpha-2 country code)
+     *    - shipping_address: Shipping address for physical items (first name, last name, address, postal code, city, ISO 3166-1 alpha-2 country code)
+     *    - group:            The app's group (optional)
+     *    - metadata:         The app's own data (max. 50 keys), only while the order is a draft (optional)
      * @throws Throwable
      */
     public function update(array $attributes = []): self
@@ -66,6 +80,8 @@ class Order extends BaseResource
     /**
      * Checkout given order from the current user.
      *
+     * A draft created with `confirm` can't be checked out once it expired (409 "confirmation_expired").
+     *
      * @throws Throwable
      */
     public function checkout(): self
@@ -98,6 +114,19 @@ class Order extends BaseResource
             ->request('DELETE', sprintf('v1/orders/%s', $this->id))->success();
     }
 
+    /**
+     * Deliveries of this order's goods; `create()` ships them (see Shipments::create()).
+     *
+     * @throws Throwable
+     */
+    public function shipments(): Shipments
+    {
+        return Shipments::builder(fn() => $this->billable->anikeenId()
+            ->request('GET', sprintf('v1/orders/%s/shipments', $this->id)))
+            ->setBillable($this->billable)
+            ->setParent($this);
+    }
+
     /**
      * Get order items from given order.
      *

src/Id/Resources/Orders.php

@@ -36,30 +36,45 @@ class Orders extends BaseCollection
      *     },
      *     shipping_address: null|array{
      *          company_name: null|string,
-     *          first_name:  string,
+     *          first_name: string,
      *          last_name: string,
-     *          address: null|string,
+     *          address: string,
-     *          address_2: string,
+     *          address_2: null|string,
      *          house_number: null|string,
      *          city: string,
-     *          state: string,
+     *          state: null|string,
      *          postal_code: string,
      *          country_iso: string,
      *          phone_number: null|string,
      *          email: null|string
      *     },
+     *     group?: null|string,
+     *     confirm?: bool,
+     *     return_url?: null|string,
+     *     metadata?: null|array,
      *     items: array<array{
-     *         type:        string,
+     *         type:         string,
-     *         name:        string,
+     *         name:         string,
-     *         description: string,
+     *         description?: null|string,
-     *         price:       float|int,
+     *         image_url?:   null|string,
-     *         unit:        string,
+     *         price?:       float|int|string,
-     *         units:       int
+     *         gross_price?: float|int|string,
+     *         unit:         string,
+     *         units:        int
      *     }>
      * } $attributes The order data:
      *   - billing_address:  Billing address (ISO 3166-1 alpha-2 country code)
-     *   - shipping_address: Shipping address (first name, last name, ISO 3166-1 alpha-2 country code)
+     *   - shipping_address: Shipping address for physical items (first name, last name, address, postal code, city, ISO 3166-1 alpha-2 country code)
-     *   - items:            Array of order items (each with type, name, price, unit, units, and quantity)
+     *   - group:            The app's group, e.g. a team (optional)
+     *   - confirm:          Trusted apps: leave confirming and paying to the user (confirmation_url, expires after 24 hours; optional)
+     *   - return_url:       Where the user returns after confirming (same origin as one of the app's redirect URIs; optional)
+     *   - metadata:         The app's own data (max. 50 keys), returned as is in the API and webhooks (optional)
+     *   - items:            Array of order items:
+     *       - type:        digital, physical or physical-reduced (VAT category)
+     *       - price/gross_price: net or gross unit price, one of both
+     *       - unit:        hour, day, week, month, year, onetime or piece
+     *       - image_url:   http(s) URL of a product image; Anikeen ID copies it, so it stays
+     *                      visible on the order and invoice when the shop removes it later
      * @throws Throwable
      */
     public function create(array $attributes = []): Order

src/Id/Resources/Preference.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+/**
+ * A preference of a user: a JSON value under a namespace and a key. `version` is opaque: it only
+ * goes up (per user, not consecutive per key) and is what ifVersion (`If-Match`) compares.
+ * JSON objects come back as stdClass, so `{}` stays an object.
+ *
+ * @property string $namespace
+ * @property string $key
+ * @property mixed $value
+ * @property int $version
+ * @property string $updated_at
+ * @property object{type: string, client_id: ?string} $updated_by `type` "user" (written with a user token) or "app"
+ */
+class Preference extends BaseResource
+{
+    /**
+     * The write that returned this preference created the key (201). False for reads, updates and
+     * writes of the value already stored.
+     */
+    public function wasCreated(): bool
+    {
+        return $this->result->response()?->getStatusCode() === 201;
+    }
+}

src/Id/Resources/Preferences.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+/**
+ * The preferences of a user in one namespace, sorted by key (at most 50, no pagination).
+ */
+class Preferences extends BaseCollection
+{
+    /**
+     * The preference of a key; null when it isn't set. Reads the list, no request.
+     */
+    public function find(string $id): ?Preference
+    {
+        $data = $this->item($id);
+
+        if ($data === null) {
+            return null;
+        }
+
+        $result = clone $this->result;
+        $result->data = $data;
+
+        return new Preference(fn () => $result);
+    }
+
+    /**
+     * The value of a key, or $default when it isn't set.
+     */
+    public function get(string $key, mixed $default = null): mixed
+    {
+        $data = $this->item($key);
+
+        return $data !== null ? $data->value : $default;
+    }
+
+    public function has(string $key): bool
+    {
+        return $this->item($key) !== null;
+    }
+
+    /**
+     * The values by key.
+     *
+     * @return array<string, mixed>
+     */
+    public function values(): array
+    {
+        $values = [];
+
+        foreach ((array) $this->result->data as $data) {
+            $values[$data->key] = $data->value;
+        }
+
+        return $values;
+    }
+
+    private function item(string $key): ?object
+    {
+        foreach ((array) $this->result->data as $data) {
+            if (($data->key ?? null) === $key) {
+                return $data;
+            }
+        }
+
+        return null;
+    }
+}

src/Id/Resources/Shipment.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use Anikeen\Id\Concerns\HasBillable;
+use Anikeen\Id\Concerns\HasParent;
+use Throwable;
+
+/**
+ * @property string $id
+ * @property string $number delivery note number, e.g. LS-2026-0001
+ * @property string $order_id
+ * @property null|string $carrier
+ * @property null|string $tracking_number
+ * @property null|string $tracking_url
+ * @property array $items order_item_id, name, description, units
+ * @property object $shipping_address
+ * @property null|string $note
+ * @property string $shipped_at
+ */
+class Shipment extends BaseResource
+{
+    use HasBillable;
+    use HasParent;
+
+    /**
+     * The delivery note as PDF (binary string).
+     *
+     * @throws Throwable
+     */
+    public function deliveryNote(): string
+    {
+        $result = $this->billable->anikeenId()
+            ->request('GET', sprintf('v1/orders/%s/shipments/%s/delivery-note', $this->order_id, $this->id));
+
+        return (string) $result->response?->getBody();
+    }
+}

src/Id/Resources/Shipments.php

@@ -0,0 +1,63 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use Anikeen\Id\Concerns\HasBillable;
+use Anikeen\Id\Concerns\HasParent;
+use Throwable;
+
+/**
+ * Deliveries of an order's physical goods. Each one adds a delivery note to the customer's
+ * order documents on Anikeen ID.
+ */
+class Shipments extends BaseCollection
+{
+    use HasBillable;
+    use HasParent;
+
+    /**
+     * Ship goods of a paid order. Only the app that created the order (or a trusted app) can.
+     *
+     * Without `items`, everything physical that hasn't been shipped yet is shipped. Items and
+     * the shipping address are stored as they are now; the user sees them on the delivery note.
+     *
+     * @param array{
+     *     carrier?: string,
+     *     tracking_number?: string,
+     *     tracking_url?: string,
+     *     note?: string,
+     *     shipped_at?: string,
+     *     notify_customer?: bool,
+     *     items?: array<array{order_item_id: string, units?: float|int|string}>
+     * } $attributes
+     *   - carrier:         e.g. "DHL"
+     *   - tracking_url:    http(s) link to track the parcel, shown to the user
+     *   - shipped_at:      when it was sent (default: now, not in the future)
+     *   - notify_customer: Anikeen ID mails the user with the delivery note (default true);
+     *                      false if your shop sends its own mail
+     *   - items:           physical items of the order and how many of them (default: all left)
+     *
+     * Errors (ResourceException with the HTTP status): 409 when the order isn't paid or nothing
+     * is left to ship, 422 for items that aren't physical items of the order or exceed what's left.
+     *
+     * @throws Throwable
+     */
+    public function create(array $attributes = []): Shipment
+    {
+        return (new Shipment(fn() => $this->billable->anikeenId()
+            ->request('POST', sprintf('v1/orders/%s/shipments', $this->parent->id), $attributes)))
+            ->setBillable($this->billable)
+            ->setParent($this->parent);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function find(string $id): ?Shipment
+    {
+        return (new Shipment(fn() => $this->billable->anikeenId()
+            ->request('GET', sprintf('v1/orders/%s/shipments/%s', $this->parent->id, $id))))
+            ->setBillable($this->billable)
+            ->setParent($this->parent);
+    }
+}

src/Id/Resources/Subscription.php

@@ -1,110 +1,124 @@
-<?php
+<?php
-
+
-namespace Anikeen\Id\Resources;
+namespace Anikeen\Id\Resources;
-
+
-use Anikeen\Id\Concerns\HasBillable;
+use Anikeen\Id\Concerns\HasBillable;
-use Anikeen\Id\Contracts\AppTokenRepository;
+use Anikeen\Id\Concerns\HasConfirmationUrl;
-use Throwable;
+use Anikeen\Id\Concerns\HasSubscriptionStatus;
-
+use Anikeen\Id\Contracts\AppTokenRepository;
-/**
+use Throwable;
- * @property string $id
+
- * @property string $name
+/**
- * @property string $description
+ * @property string $id
- * @property string $unit
+ * @property string $name
- * @property float $price
+ * @property string $description
- * @property float $vat_rate
+ * @property string $unit
- * @property array $payload
+ * @property float $price
- * @property string $ends_at
+ * @property ?float $monthly_cap net, at most this per calendar month (hour and day units)
- * @property string $webhook_url
+ * @property ?float $expected_monthly_price gross estimate for a month (720 hours, at most the monthly cap)
- * @property string $webhook_secret
+ * @property ?string $predecessor_id the subscription this one replaced (a resize); they share the monthly cap
- */
+ * @property float $vat_rate
-class Subscription extends BaseResource
+ * @property array $payload
-{
+ * @property bool $active
-    use HasBillable;
+ * @property bool $autorenew
-
+ * @property bool $cancelled
-    /**
+ * @property ?string $status draft, trial, active, paused, cancelling, expired or cancelled, see status()
-     * Update a given subscription from the current user.
+ * @property ?string $starts_at
-     *
+ * @property string $ends_at
-     * @param array{
+ * @property ?string $cancels_at when a scheduled cancellation takes effect
-     *      group: string,
+ * @property ?string $trial_ends_at
-     *      name: string,
+ * @property ?string $trial_payment_method required or optional with a trial (TrialPaymentMethod), null without
-     *      description: null|string,
+ * @property ?string $cancellation_reason why the billing cancelled it (CancellationReason), null otherwise
-     *      unit: string,
+ * @property ?object $discount {label, percent_off, amount_off, duration, duration_in_periods, periods_remaining}; periods_remaining is null for `forever`, 0 once it ended
-     *      price: float,
+ * @property null|string $confirmation_url where the user confirms it (third-party apps)
-     *      vat_rate: float,
+ */
-     *      payload: null|array,
+class Subscription extends BaseResource
-     *      ends_at: null|string,
+{
-     *      webhook_url: null|string,
+    use HasBillable;
-     *      webhook_secret: null|string
+    use HasConfirmationUrl;
-     *  } $attributes The subscription data:
+    use HasSubscriptionStatus;
-     *    - group:          The group (optional)
+
-     *    - name:           The name (required when set)
+    /**
-     *    - description:    The description (optional)
+     * Update a given subscription from the current user.
-     *    - unit:           The unit (required when set, e.g. "hour", "day", "week", "month", "year")
+     *
-     *    - price:          The price per unit (required when set)
+     * @param array{
-     *    - vat_rate:       The VAT rate (required when set)
+     *      group: string,
-     *    - payload:        The payload (optional)
+     *      name: string,
-     *    - ends_at:        The end date (optional)
+     *      description: null|string,
-     *    - webhook_url:    The webhook URL (optional)
+     *      unit: string,
-     *    - webhook_secret: The webhook secret (optional)
+     *      price: float,
-     * @throws Throwable
+     *      monthly_cap?: null|float,
-     */
+     *      vat_rate: float,
-    public function update(array $attributes): self
+     *      payload: null|array,
-    {
+     *      ends_at: null|string
-        return (new self(fn() => $this->billable->anikeenId()
+     *  } $attributes The subscription data:
-            ->request('PUT', sprintf('v1/subscriptions/%s', $this->id), $attributes)))
+     *    - group:          The group (optional)
-            ->setBillable($this->billable);
+     *    - name:           The name (required when set)
-    }
+     *    - description:    The description (optional)
-
+     *    - unit:           The unit (required when set, e.g. "hour", "day", "week", "month", "year")
-    /**
+     *    - price:          The price per unit (required when set)
-     * Force given subscription to check out (trusted apps only).
+     *    - monthly_cap:    Net, at most this per calendar month (hour and day units; optional)
-     *
+     *    - vat_rate:       The VAT rate (required when set)
-     * @throws Throwable
+     *    - payload:        The payload (optional)
-     */
+     *    - ends_at:        The end date (optional)
-    public function checkout(): self
+     * @throws Throwable
-    {
+     */
-        return (new self(fn() => $this->billable->anikeenId()
+    public function update(array $attributes): self
-            ->request('PUT', sprintf('v1/subscriptions/%s/checkout', $this->id))))
+    {
-            ->setBillable($this->billable);
+        return (new self(fn() => $this->billable->anikeenId()
-    }
+            ->request('PUT', sprintf('v1/subscriptions/%s', $this->id), $attributes)))
-
+            ->setBillable($this->billable);
-    /**
+    }
-     * Revoke a given running subscription from the current user.
+
-     *
+    /**
-     * @throws Throwable
+     * Force given subscription to check out (trusted apps only).
-     */
+     *
-    public function revoke(bool $refund = false): self
+     * @throws Throwable
-    {
+     */
-        $attributes = [
+    public function checkout(): self
-            'refund' => $refund,
+    {
-        ];
+        return (new self(fn() => $this->billable->anikeenId()
-
+            ->request('PUT', sprintf('v1/subscriptions/%s/checkout', $this->id))))
-        return (new self(fn() => $this->billable->anikeenId()
+            ->setBillable($this->billable);
-            ->request('PUT', sprintf('v1/subscriptions/%s/revoke', $this->id), $attributes)))
+    }
-            ->setBillable($this->billable);
+
-    }
+    /**
-
+     * Revoke a given running subscription from the current user.
-    /**
+     *
-     * Pause a given running subscription from the current user.
+     * @throws Throwable
-     *
+     */
-     * @throws Throwable
+    public function revoke(bool $refund = false): self
-     */
+    {
-    public function pause(): self
+        $attributes = [
-    {
+            'refund' => $refund,
-        return (new self(fn() => $this->billable->anikeenId()
+        ];
-            ->request('PUT', sprintf('v1/subscriptions/%s/pause', $this->id))))
+
-            ->setBillable($this->billable);
+        return (new self(fn() => $this->billable->anikeenId()
-    }
+            ->request('PUT', sprintf('v1/subscriptions/%s/revoke', $this->id), $attributes)))
-
+            ->setBillable($this->billable);
-    /**
+    }
-     * Resume a given running subscription from the current user.
+
-     *
+    /**
-     * @throws Throwable
+     * Pause a given running subscription from the current user.
-     */
+     *
-    public function resume(): self
+     * @throws Throwable
-    {
+     */
-        return (new self(fn() => $this->billable->anikeenId()
+    public function pause(): self
-            ->request('PUT', sprintf('v1/subscriptions/%s/resume', $this->id))))
+    {
-            ->setBillable($this->billable);
+        return (new self(fn() => $this->billable->anikeenId()
-    }
+            ->request('PUT', sprintf('v1/subscriptions/%s/pause', $this->id))))
-}
+            ->setBillable($this->billable);
+    }
+
+    /**
+     * Resume a given running subscription from the current user.
+     *
+     * @throws Throwable
+     */
+    public function resume(): self
+    {
+        return (new self(fn() => $this->billable->anikeenId()
+            ->request('PUT', sprintf('v1/subscriptions/%s/resume', $this->id))))
+            ->setBillable($this->billable);
+    }
+}

src/Id/Resources/Subscriptions.php

@@ -20,22 +20,32 @@ class Subscriptions extends BaseCollection
      *      description: null|string,
      *      unit: string,
      *      price: float,
+     *      monthly_cap?: null|float,
+     *      predecessor_id?: null|string,
      *      vat_rate: float,
      *      payload: null|array,
      *      ends_at: null|string,
-     *      webhook_url: null|string,
+     *      trial_days?: null|int,
-     *      webhook_secret: null|string
+     *      trial_ends_at?: null|string,
+     *      trial_once?: bool,
+     *      trial_payment_method?: null|string,
+     *      discount?: null|array{label: string, percent_off?: float|string, amount_off?: float|string, duration: string, duration_in_periods?: int}
      *  } $attributes The subscription data:
      *    - group:          The group (optional)
      *    - name:           The name
      *    - description:    The description (optional)
      *    - unit:           The unit (e.g. "hour", "day", "week", "month", "year")
      *    - price:          The price per unit
+     *    - monthly_cap:    Net, at most this per calendar month (hour and day units, max. 2 decimals; optional)
+     *    - predecessor_id: The subscription this one replaces (a resize); both share the monthly cap (optional)
      *    - vat_rate:       The VAT rate (required when set)
      *    - payload:        The payload (optional)
      *    - ends_at:        The end date (optional)
-     *    - webhook_url:    The webhook URL (optional)
+     *    - trial_days:     A free trial of 1–365 days from the user's confirmation on (optional)
-     *    - webhook_secret: The webhook secret (optional)
+     *    - trial_ends_at:  Or a fixed end of the free trial (ISO 8601, in the future; optional)
+     *    - trial_once:     Refuse the trial if the user already had one with the app in the group (optional)
+     *    - trial_payment_method: TrialPaymentMethod::REQUIRED (default) or ::OPTIONAL, only with a trial (optional)
+     *    - discount:       A discount per billed period, see AppSubscriptions::create() (optional)
      * @throws Throwable
      */
     public function create(array $attributes): Subscription

src/Id/Support/AppRequest.php

@@ -5,36 +5,40 @@ namespace Anikeen\Id\Support;
 use Anikeen\Id\AnikeenId;
 use Anikeen\Id\Contracts\AppTokenRepository;
 use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Exceptions\PreconditionFailedException;
 use Anikeen\Id\Result;
 use GuzzleHttp\Exception\GuzzleException;
 use Throwable;
 
 /**
  * Sends a request with the app's own token (client credentials). A rejected token is renewed
- * once; every failure ends in an ApiException with status and error code.
+ * once; every failure ends in an ApiException with status and error code (a 412 in a
+ * PreconditionFailedException).
  */
 final class AppRequest
 {
     /**
+     * @param array<string, string> $headers Extra request headers, e.g. `If-Match`.
      * @throws ApiException
      */
-    public static function send(string $method, string $path, ?array $payload = null, array $query = []): Result
+    public static function send(string $method, string $path, ?array $payload = null, array $query = [], array $headers = []): Result
     {
-        $result = self::attempt($method, $path, $payload, $query);
+        $result = self::attempt($method, $path, $payload, $query, $headers);
 
         if ($result->status === 401) {
             $tokens = app(AppTokenRepository::class);
 
             if (method_exists($tokens, 'forgetAccessToken')) {
                 $tokens->forgetAccessToken();
-                $result = self::attempt($method, $path, $payload, $query);
+                $result = self::attempt($method, $path, $payload, $query, $headers);
             }
         }
 
         if (!$result->success()) {
             $body = is_object($result->data) ? $result->data : null;
+            $exception = $result->status === 412 ? PreconditionFailedException::class : ApiException::class;
 
-            throw new ApiException(
+            throw new $exception(
                 sprintf('Anikeen ID request %s %s failed: %s', $method, $path, $body->message ?? $result->error()),
                 $result->response()?->getStatusCode() ?? 0,
                 $body->error ?? null,
@@ -48,10 +52,10 @@ final class AppRequest
     /**
      * @throws ApiException
      */
-    private static function attempt(string $method, string $path, ?array $payload, array $query): Result
+    private static function attempt(string $method, string $path, ?array $payload, array $query, array $headers = []): Result
     {
         try {
-            return app(AnikeenId::class)->asApp()->request($method, $path, $payload, $query);
+            return app(AnikeenId::class)->asApp()->request($method, $path, $payload, $query, null, false, $headers);
         } catch (ApiException $e) {
             throw $e;
         } catch (GuzzleException|Throwable $e) {

src/Id/Support/PreferenceRequest.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace Anikeen\Id\Support;
+
+use InvalidArgumentException;
+
+/**
+ * @internal paths and preconditions of the preferences API
+ */
+final class PreferenceRequest
+{
+    /**
+     * The path with every segment URL-encoded, e.g. path('v1/preferences', 'global', 'appearance').
+     */
+    public static function path(string $base, string ...$segments): string
+    {
+        return $base . '/' . implode('/', array_map('rawurlencode', $segments));
+    }
+
+    /**
+     * `If-Match: "<version>"` (only if the stored version is this one) or `If-None-Match: *`
+     * (only if the key isn't set yet).
+     *
+     * @return array<string, string>
+     */
+    public static function conditions(?int $ifVersion, bool $createOnly = false): array
+    {
+        if ($ifVersion !== null && $createOnly) {
+            throw new InvalidArgumentException('A write is either conditional on a version or create-only, not both.');
+        }
+
+        return match (true) {
+            $ifVersion !== null => ['If-Match' => sprintf('"%d"', $ifVersion)],
+            $createOnly => ['If-None-Match' => '*'],
+            default => [],
+        };
+    }
+
+    private function __construct()
+    {
+    }
+}

src/Id/Webhooks/EventType.php

@@ -0,0 +1,92 @@
+<?php
+
+namespace Anikeen\Id\Webhooks;
+
+/**
+ * The `type` of webhook events Anikeen ID sends, e.g.
+ * `match ($event['type']) { EventType::CHECKOUT_COMPLETED => …, … }`.
+ */
+final class EventType
+{
+    public const ORDER_CREATED = 'order.created';
+    public const ORDER_COMPLETED = 'order.completed';
+    public const ORDER_PAYMENT_FAILED = 'order.payment_failed';
+    public const ORDER_CANCELLED = 'order.cancelled';
+    public const ORDER_SHIPPED = 'order.shipped';
+    /**
+     * Money was given back for an order (a refund or a partial cancellation, with a credit note);
+     * see the order's `refunds` and `refunded_total`. A full refund also cancels the order,
+     * so order.cancelled is sent too; don't rely on the order of the two events.
+     */
+    public const ORDER_REFUNDED = 'order.refunded';
+
+    public const SUBSCRIPTION_CREATED = 'subscription.created';
+    public const SUBSCRIPTION_ACTIVATED = 'subscription.activated';
+    public const SUBSCRIPTION_PAUSED = 'subscription.paused';
+    public const SUBSCRIPTION_RESUMED = 'subscription.resumed';
+    /** `data.reason`: why the billing cancelled it (CancellationReason, e.g. a trial that ended without a payment method), else null. */
+    public const SUBSCRIPTION_CANCELLED = 'subscription.cancelled';
+    public const SUBSCRIPTION_EXPIRED = 'subscription.expired';
+
+    /**
+     * The free trial of a running subscription ends in a few days (see trial_ends_at); billing
+     * starts then. `data.payment_method_missing`: the user has no payment method yet (with
+     * trial_payment_method `optional` the subscription then ends with the trial).
+     */
+    public const SUBSCRIPTION_TRIAL_WILL_END = 'subscription.trial_will_end';
+
+    /** The last discounted period of a subscription was billed; the following ones are billed at the full price. */
+    public const SUBSCRIPTION_DISCOUNT_ENDED = 'subscription.discount_ended';
+
+    /**
+     * The price, unit, name, description or discount of a running subscription changed (right away
+     * or at the period end); `data.previous_attributes` has the changed fields' old values.
+     */
+    public const SUBSCRIPTION_UPDATED = 'subscription.updated';
+
+    /**
+     * A period of a subscription was booked on its collective order, the first one included;
+     * `data.period` describes it, `data.period.first_period` is true for the subscription's first
+     * paid period (checkout or the end of a free trial). Opt-in: only endpoints that select this
+     * event get it (not through `*`).
+     */
+    public const SUBSCRIPTION_RENEWED = 'subscription.renewed';
+
+    /** The user confirmed a checkout session: all of its subscriptions are running (sent after their subscription.activated). */
+    public const CHECKOUT_COMPLETED = 'checkout.completed';
+
+    /** The user or the app cancelled a checkout session; its drafts were cancelled. */
+    public const CHECKOUT_CANCELLED = 'checkout.cancelled';
+
+    /** A checkout session was not confirmed within 24 hours; its drafts were cancelled. */
+    public const CHECKOUT_EXPIRED = 'checkout.expired';
+
+    /**
+     * A user's open monthly bill reached their billing limit: start no new paid service for them.
+     * `data.object` is the billing limit as the app reads it (with `version`), `data.reason`
+     * `booking` or `limit_changed`. Opt-in: only endpoints that select this event get it (not
+     * through `*`), and only apps that may read the limit of a user connected to them.
+     */
+    public const BILLING_LIMIT_REACHED = 'billing_limit.reached';
+
+    /**
+     * A user whose billing limit was reached has room again. `data.object` is the billing limit
+     * (with `version`), `data.reason` `limit_changed`, `limit_removed`, `voided`, `period_reset`
+     * or `order_changed`. Opt-in like BILLING_LIMIT_REACHED.
+     */
+    public const BILLING_LIMIT_AVAILABLE = 'billing_limit.available';
+
+    public const TEST = 'webhook.test';
+
+    /**
+     * @return list<string>
+     */
+    public static function all(): array
+    {
+        return array_values((new \ReflectionClass(self::class))->getConstants());
+    }
+
+    private function __construct()
+    {
+    }
+}

src/Id/Webhooks/Webhook.php

@@ -0,0 +1,71 @@
+<?php
+
+namespace Anikeen\Id\Webhooks;
+
+use Anikeen\Id\Exceptions\SignatureVerificationException;
+
+/**
+ * Verifies webhooks from Anikeen ID, like Stripe's Webhook::constructEvent().
+ *
+ * Anikeen ID signs every request with your endpoint's signing secret (whsec_…):
+ * `Anikeen-Signature: t=<unix time>,v1=<hex HMAC-SHA256 of "<t>.<raw body>">`.
+ */
+final class Webhook
+{
+    /** Requests older (or newer) than this many seconds are rejected to prevent replays. */
+    public const DEFAULT_TOLERANCE = 300;
+
+    /**
+     * Verifies the signature and returns the event: ['id', 'type', 'created', 'data' => ['object' => …]].
+     *
+     * @param  string  $payload  the raw request body (not re-encoded JSON)
+     * @param  string|null  $signatureHeader  the Anikeen-Signature header
+     *
+     * @throws SignatureVerificationException
+     */
+    public static function constructEvent(string $payload, ?string $signatureHeader, string $secret, int $tolerance = self::DEFAULT_TOLERANCE): array
+    {
+        self::verify($payload, $signatureHeader, $secret, $tolerance);
+
+        $event = json_decode($payload, true);
+
+        if (!is_array($event) || !isset($event['id'], $event['type'])) {
+            throw new SignatureVerificationException('The webhook payload is not a valid event.');
+        }
+
+        return $event;
+    }
+
+    /**
+     * @throws SignatureVerificationException
+     */
+    public static function verify(string $payload, ?string $signatureHeader, string $secret, int $tolerance = self::DEFAULT_TOLERANCE): void
+    {
+        $timestamp = null;
+        $signatures = [];
+
+        foreach (explode(',', (string) $signatureHeader) as $part) {
+            [$key, $value] = array_pad(explode('=', trim($part), 2), 2, null);
+
+            if ($key === 't' && ctype_digit((string) $value)) {
+                $timestamp = (int) $value;
+            } elseif ($key === 'v1' && $value) {
+                $signatures[] = $value;
+            }
+        }
+
+        if ($timestamp === null || $signatures === []) {
+            throw new SignatureVerificationException('The Anikeen-Signature header is missing or malformed.');
+        }
+
+        $expected = hash_hmac('sha256', "{$timestamp}.{$payload}", $secret);
+
+        if (!array_filter($signatures, fn (string $signature) => hash_equals($expected, $signature))) {
+            throw new SignatureVerificationException('The webhook signature does not match. Check the signing secret.');
+        }
+
+        if ($tolerance > 0 && abs(time() - $timestamp) > $tolerance) {
+            throw new SignatureVerificationException('The webhook timestamp is outside the tolerance.');
+        }
+    }
+}

tests/Id/AppChargesTest.php

@@ -0,0 +1,269 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Resources\AppCharge;
+use Anikeen\Id\Resources\BillingLimit;
+use DateTimeImmutable;
+
+class AppChargesTest extends TestCase
+{
+    private function sentCall(int $index): string
+    {
+        $request = $this->sent[$index]['request'];
+
+        return $request->getMethod() . ' ' . $request->getUri()->getPath() . ' ' . $request->getHeaderLine('Authorization');
+    }
+
+    private function charge(array $overrides = []): array
+    {
+        return ['data' => [
+            'object' => 'charge', 'id' => '01JCHARGE', 'user_id' => '01JUSER', 'status' => 'open',
+            'idempotency_key' => 'shipment-123', 'name' => 'Signed card', 'description' => null,
+            'type' => 'physical', 'quantity' => 2, 'unit' => 'piece', 'unit_price' => '4.000000',
+            'net_amount' => '8.00', 'gross_amount' => '9.52', 'currency_iso' => 'EUR', 'group' => null,
+            'occurred_at' => '2026-11-06T10:00:00+00:00', 'reference' => 'order-77', 'metadata' => ['parcel' => 'p-1'],
+            'order_id' => '01JORDER', 'voided_at' => null, 'void_reason' => null, 'created_at' => '2026-11-06T10:00:01+00:00',
+            ...$overrides,
+        ]];
+    }
+
+    private function limit(array $overrides = []): array
+    {
+        return ['data' => [
+            'object' => 'billing_limit', 'user_id' => '01JUSER', 'currency' => 'EUR', 'basis' => 'gross',
+            'limit' => '100.00', 'used' => '82.40', 'used_by_app' => '60.00', 'remaining' => '17.60',
+            'remaining_net' => '14.78', 'vat_rate' => 19, 'reached' => false,
+            'resets_at' => '2026-12-01T02:00:00Z', 'version' => 7,
+            ...$overrides,
+        ]];
+    }
+
+    public function test_a_charge_is_booked_with_the_app_token(): void
+    {
+        $this->respond(201, $this->charge());
+
+        $attributes = [
+            'idempotency_key' => 'shipment-123',
+            'name' => 'Signed card',
+            'type' => 'physical',
+            'quantity' => 2,
+            'unit_price' => '4.00',
+            'reference' => 'order-77',
+            'metadata' => ['parcel' => 'p-1'],
+        ];
+        $charge = app(AnikeenId::class)->createChargeForUser('01JUSER', $attributes);
+
+        $this->assertSame('POST /api/v1/client/users/01JUSER/charges Bearer app-token', $this->sentCall(0));
+        $this->assertSame($attributes, $this->sentJson(0));
+        $this->assertInstanceOf(AppCharge::class, $charge);
+        $this->assertSame('01JCHARGE', $charge->id());
+        $this->assertSame('open', $charge->status());
+        $this->assertTrue($charge->isOpen());
+        $this->assertFalse($charge->isBilled());
+        $this->assertFalse($charge->isVoided());
+        $this->assertSame('8.00', $charge->netAmount());
+        $this->assertSame('9.52', $charge->grossAmount());
+        $this->assertSame('01JORDER', $charge->orderId());
+        $this->assertSame(['parcel' => 'p-1'], $charge->metadata());
+        $this->assertEquals(new DateTimeImmutable('2026-11-06T10:00:00+00:00'), $charge->occurredAt());
+        $this->assertSame(2, $charge->quantity);
+        $this->assertSame('order-77', $charge->reference);
+        $this->assertNull($charge->voided_at);
+        $this->assertSame('Signed card', $charge->jsonSerialize()['name']);
+    }
+
+    public function test_empty_metadata_is_an_empty_array(): void
+    {
+        $this->respond(200, $this->charge(['metadata' => new \stdClass()]));
+
+        $this->assertSame([], app(AnikeenId::class)->findChargeForUser('01JUSER', '01JCHARGE')->metadata());
+    }
+
+    public function test_a_charge_is_found_with_the_app_token(): void
+    {
+        $this->respond(200, $this->charge(['status' => 'billed']));
+
+        $charge = app(AnikeenId::class)->findChargeForUser('01JUSER', '01JCHARGE');
+
+        $this->assertSame('GET /api/v1/client/users/01JUSER/charges/01JCHARGE Bearer app-token', $this->sentCall(0));
+        $this->assertTrue($charge->isBilled());
+    }
+
+    public function test_a_charge_is_voided_with_and_without_a_reason(): void
+    {
+        $voided = ['status' => 'voided', 'order_id' => null, 'voided_at' => '2026-11-06T11:00:00+00:00', 'void_reason' => 'Parcel lost'];
+        $this->respond(200, $this->charge($voided));
+        $this->respond(200, $this->charge($voided));
+
+        $charge = app(AnikeenId::class)->voidChargeForUser('01JUSER', '01JCHARGE', 'Parcel lost');
+        app(AnikeenId::class)->voidChargeForUser('01JUSER', '01JCHARGE');
+
+        $this->assertSame('POST /api/v1/client/users/01JUSER/charges/01JCHARGE/void Bearer app-token', $this->sentCall(0));
+        $this->assertSame(['reason' => 'Parcel lost'], $this->sentJson(0));
+        $this->assertSame('POST /api/v1/client/users/01JUSER/charges/01JCHARGE/void Bearer app-token', $this->sentCall(1));
+        $this->assertSame([], $this->sentJson(1));
+        $this->assertTrue($charge->isVoided());
+        $this->assertNull($charge->orderId());
+        $this->assertSame('Parcel lost', $charge->void_reason);
+    }
+
+    public function test_path_segments_are_encoded(): void
+    {
+        $this->respond(200, $this->charge());
+
+        app(AnikeenId::class)->findChargeForUser('01J/USER', '01J CHARGE');
+
+        $this->assertSame('/api/v1/client/users/01J%2FUSER/charges/01J%20CHARGE', $this->sent[0]['request']->getUri()->getPath());
+    }
+
+    public function test_a_charge_over_the_billing_limit_carries_the_details(): void
+    {
+        $this->respond(409, [
+            'message' => 'The customer\'s billing limit is reached.', 'error' => 'billing_limit_reached',
+            'limit' => '100.00', 'used' => '97.40', 'remaining' => '2.60', 'remaining_net' => '2.18',
+            'required' => '4.76', 'currency' => 'EUR', 'resets_at' => '2026-12-01T02:00:00Z',
+        ]);
+
+        try {
+            app(AnikeenId::class)->createChargeForUser('01JUSER', ['idempotency_key' => 'k', 'name' => 'Card', 'quantity' => 1, 'unit_price' => '4.00']);
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isBillingLimitReached());
+            $this->assertTrue($e->isConflict());
+            $this->assertSame(409, $e->status);
+            $this->assertSame('2.60', $e->body()->remaining);
+            $this->assertSame('4.76', $e->body()->required);
+            $this->assertSame('2026-12-01T02:00:00Z', $e->body()->resets_at);
+        }
+    }
+
+    public function test_other_conflicts_are_not_the_billing_limit(): void
+    {
+        $this->respond(409, ['message' => 'The charge is more than this app may charge at once.', 'error' => 'charge_exceeds_maximum', 'max_charge_net' => '50.00']);
+
+        try {
+            app(AnikeenId::class)->createChargeForUser('01JUSER', ['idempotency_key' => 'k', 'name' => 'Card', 'quantity' => 1, 'unit_price' => '60.00']);
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertFalse($e->isBillingLimitReached());
+            $this->assertSame('charge_exceeds_maximum', $e->error);
+            $this->assertSame('50.00', $e->body()->max_charge_net);
+        }
+    }
+
+    public function test_an_already_billed_charge_cannot_be_voided(): void
+    {
+        $this->respond(409, ['message' => 'The charge is on a closed bill; only a refund of that order credits it.', 'error' => 'charge_already_billed', 'charge_id' => '01JCHARGE']);
+
+        try {
+            app(AnikeenId::class)->voidChargeForUser('01JUSER', '01JCHARGE');
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertSame('charge_already_billed', $e->error);
+            $this->assertSame('01JCHARGE', $e->body()->charge_id);
+        }
+    }
+
+    public function test_an_unknown_charge_is_not_found(): void
+    {
+        $this->respond(404, ['message' => 'Charge not found.', 'error' => 'charge_not_found']);
+
+        try {
+            app(AnikeenId::class)->findChargeForUser('01JUSER', '01JOTHER');
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isNotFound());
+            $this->assertSame('charge_not_found', $e->error);
+        }
+    }
+
+    public function test_the_billing_limit_is_read_with_the_app_token(): void
+    {
+        $this->respond(200, $this->limit());
+
+        $limit = app(AnikeenId::class)->billingLimitForUser('01JUSER');
+
+        $this->assertSame('GET /api/v1/client/users/01JUSER/billing-limit Bearer app-token', $this->sentCall(0));
+        $this->assertInstanceOf(BillingLimit::class, $limit);
+        $this->assertTrue($limit->hasLimit());
+        $this->assertSame('100.00', $limit->limit());
+        $this->assertSame('82.40', $limit->used());
+        $this->assertSame('60.00', $limit->usedByApp());
+        $this->assertSame('17.60', $limit->remaining());
+        $this->assertSame('14.78', $limit->remainingNet());
+        $this->assertSame(19.0, $limit->vatRate());
+        $this->assertSame('EUR', $limit->currency());
+        $this->assertFalse($limit->isReached());
+        $this->assertEquals(new DateTimeImmutable('2026-12-01T02:00:00Z'), $limit->resetsAt());
+        $this->assertSame(7, $limit->version());
+        $this->assertSame('gross', $limit->basis);
+    }
+
+    public function test_without_a_limit_the_app_sees_only_its_own_share(): void
+    {
+        $this->respond(200, $this->limit(['limit' => null, 'used' => null, 'remaining' => null, 'remaining_net' => null, 'vat_rate' => null]));
+
+        $limit = app(AnikeenId::class)->billingLimitForUser('01JUSER');
+
+        $this->assertFalse($limit->hasLimit());
+        $this->assertNull($limit->limit());
+        $this->assertNull($limit->used());
+        $this->assertNull($limit->remaining());
+        $this->assertNull($limit->remainingNet());
+        $this->assertNull($limit->vatRate());
+        $this->assertSame('60.00', $limit->usedByApp());
+        $this->assertTrue($limit->allows('100000.00'));
+    }
+
+    public function test_allows_compares_with_the_remaining_amount(): void
+    {
+        $limit = new BillingLimit((object) $this->limit()['data']);
+
+        $this->assertTrue($limit->allows('17.60'));
+        $this->assertTrue($limit->allows('17.6'));
+        $this->assertTrue($limit->allows('4.76'));
+        $this->assertTrue($limit->allows(17.6));
+        $this->assertTrue($limit->allows(17));
+        $this->assertFalse($limit->allows('17.61'));
+        $this->assertFalse($limit->allows('17.600001'));
+        $this->assertFalse($limit->allows('100.00'));
+        $this->assertFalse($limit->allows(1000));
+    }
+
+    public function test_a_reached_or_zero_limit_allows_nothing(): void
+    {
+        $reached = new BillingLimit((object) $this->limit(['used' => '100.00', 'remaining' => '0.00', 'remaining_net' => '0.00', 'reached' => true])['data']);
+        $zero = new BillingLimit((object) $this->limit(['limit' => '0.00', 'used' => '0.00', 'remaining' => '0.00', 'reached' => true])['data']);
+
+        $this->assertTrue($reached->isReached());
+        $this->assertFalse($reached->allows('0.01'));
+        $this->assertTrue($zero->hasLimit());
+        $this->assertFalse($zero->allows('0.01'));
+    }
+
+    public function test_the_user_s_own_limit_has_no_app_share(): void
+    {
+        $limit = new BillingLimit((object) ['object' => 'billing_limit', 'user_id' => '01JUSER', 'currency' => 'EUR', 'basis' => 'gross', 'limit' => null, 'used' => '12.00', 'remaining' => null, 'remaining_net' => null, 'vat_rate' => 19.0, 'reached' => false, 'resets_at' => '2026-12-01T02:00:00Z', 'version' => 0]);
+
+        $this->assertSame('12.00', $limit->used());
+        $this->assertNull($limit->usedByApp());
+        $this->assertSame(0, $limit->version());
+    }
+
+    public function test_a_refused_limit_read_is_an_api_exception(): void
+    {
+        $this->respond(403, ['message' => 'This app may not read customers\' billing limits.', 'error' => 'billing_limit_not_enabled']);
+
+        try {
+            app(AnikeenId::class)->billingLimitForUser('01JUSER');
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertSame(403, $e->status);
+            $this->assertSame('billing_limit_not_enabled', $e->error);
+            $this->assertFalse($e->isBillingLimitReached());
+        }
+    }
+}

tests/Id/AppOrdersTest.php

@@ -4,6 +4,8 @@ namespace Anikeen\Id\Tests;
 
 use Anikeen\Id\AnikeenId;
 use Anikeen\Id\Billable;
+use Anikeen\Id\Exceptions\ApiException;
+use GuzzleHttp\Psr7\Response;
 use Illuminate\Database\Eloquent\Model;
 
 class AppOrdersTest extends TestCase
@@ -68,4 +70,65 @@ class AppOrdersTest extends TestCase
         $this->assertNull($orders->find('o1'));
         $this->assertSame('o1', $orders->find('o1')->id);
     }
+
+    public function test_orders_list_their_lines_and_invoice(): void
+    {
+        $this->respond(200, ['data' => [
+            'id' => 'o1',
+            'user_id' => '01JUSER',
+            'group' => 'team-1',
+            'metadata' => ['topup' => '7'],
+            'items' => [
+                ['id' => 'i1', 'subscription_id' => '01JSUB', 'units' => 1, 'price' => 10, 'period_start' => '2026-11-01T00:00:00+00:00', 'period_end' => '2026-12-01T00:00:00+00:00', 'net_amount' => 10, 'discount' => null],
+                ['id' => 'i2', 'subscription_id' => '01JSUB', 'units' => 1, 'price' => -2, 'period_start' => '2026-11-01T00:00:00+00:00', 'period_end' => '2026-12-01T00:00:00+00:00', 'net_amount' => -2, 'discount' => ['label' => 'SUMMER20', 'percent_off' => 20, 'amount_off' => null]],
+            ],
+            'invoice' => ['id' => 'inv1', 'number' => 'RE-2026-0001', 'status' => 'completed', 'pdf_url' => 'https://id.test/api/v1/client/orders/o1/invoice'],
+        ]]);
+
+        $order = $this->owner()->appOrders()->find('o1');
+
+        $this->assertSame('7', $order->metadata->topup);
+        $this->assertSame(8, array_sum(array_map(fn ($item) => $item->net_amount, array_filter($order->items, fn ($item) => $item->subscription_id === '01JSUB'))));
+        $this->assertSame('SUMMER20', $order->items[1]->discount->label);
+        $this->assertSame('RE-2026-0001', $order->invoice->number);
+    }
+
+    public function test_the_invoice_pdf_is_downloaded_with_the_app_token(): void
+    {
+        $this->http->append(new Response(200, ['Content-Type' => 'application/pdf'], '%PDF-1.7 invoice'));
+        $this->respond(200, ['data' => ['id' => 'o1', 'user_id' => '01JUSER']]);
+        $this->http->append(new Response(200, ['Content-Type' => 'application/pdf'], '%PDF-1.7 invoice'));
+
+        $this->assertSame('%PDF-1.7 invoice', app(AnikeenId::class)->appOrders()->invoicePdf('o1'));
+        $this->assertSame('%PDF-1.7 invoice', $this->owner()->appOrders()->invoicePdf('o1'));
+
+        $calls = array_map(fn ($entry) => $entry['request']->getMethod() . ' ' . $entry['request']->getUri()->getPath() . ' ' . $entry['request']->getHeaderLine('Authorization'), $this->sent);
+        $this->assertSame([
+            'GET /api/v1/client/orders/o1/invoice Bearer app-token',
+            'GET /api/v1/client/orders/o1 Bearer app-token',
+            'GET /api/v1/client/orders/o1/invoice Bearer app-token',
+        ], $calls);
+    }
+
+    public function test_an_invoice_that_is_not_ready_is_a_conflict(): void
+    {
+        $this->respond(409, ['message' => 'The invoice document is still being created.', 'error' => 'invoice_not_ready']);
+        $this->respond(200, ['data' => ['id' => 'o1', 'user_id' => 'someone-else']]);
+
+        try {
+            app(AnikeenId::class)->appOrders()->invoicePdf('o1');
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isConflict());
+            $this->assertSame('invoice_not_ready', $e->error);
+        }
+
+        try {
+            $this->owner()->appOrders()->invoicePdf('o1');
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isNotFound());
+            $this->assertSame('order_not_found', $e->error);
+        }
+    }
 }

tests/Id/AppSubscriptionsTest.php

@@ -4,7 +4,10 @@ namespace Anikeen\Id\Tests;
 
 use Anikeen\Id\AnikeenId;
 use Anikeen\Id\Billable;
+use Anikeen\Id\Enums\CancellationReason;
+use Anikeen\Id\Enums\TrialPaymentMethod;
 use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Resources\AppSubscription;
 use GuzzleHttp\Exception\ConnectException;
 use GuzzleHttp\Psr7\Request;
 use Illuminate\Database\Eloquent\Model;
@@ -76,6 +79,98 @@ class AppSubscriptionsTest extends TestCase
         $this->assertSame(['refund' => true], $this->sentJson(4));
     }
 
+    public function test_a_running_service_is_checked_out_from_its_start(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(200, $this->subscription(['active' => true]));
+
+        $subscription = $this->owner()->appSubscriptions()->create(['name' => '.de TLD', 'unit' => 'year', 'price' => '5.19']);
+        $subscription->checkout(new \DateTimeImmutable('2026-05-19 11:33:58', new \DateTimeZone('UTC')));
+
+        $this->assertSame(['starts_at' => '2026-05-19T11:33:58+00:00'], $this->sentJson(1));
+    }
+
+    public function test_a_checkout_without_arguments_sends_no_body(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(200, $this->subscription(['active' => true]));
+
+        $this->owner()->appSubscriptions()->create(['name' => 'Server', 'unit' => 'hour', 'price' => 1])->checkout();
+
+        $request = $this->sent[1]['request'];
+        $this->assertSame('PUT /api/v1/client/subscriptions/01JSUB/checkout', $request->getMethod() . ' ' . $request->getUri()->getPath());
+        $this->assertSame('', (string) $request->getBody());
+        $this->assertFalse($request->hasHeader('Content-Type'));
+    }
+
+    public function test_a_checkout_from_a_date_sends_only_the_start(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(200, $this->subscription(['active' => true]));
+
+        $this->owner()->appSubscriptions()->create(['name' => '.de TLD', 'unit' => 'year', 'price' => '5.19'])
+            ->checkout('2026-05-19T11:33:58+00:00');
+
+        $this->assertSame('{"starts_at":"2026-05-19T11:33:58+00:00"}', (string) $this->sent[1]['request']->getBody());
+    }
+
+    public function test_elapsed_periods_are_billed_up_to_the_ceiling(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(200, $this->subscription(['active' => true]));
+
+        $this->owner()->appSubscriptions()->create(['name' => '.de TLD', 'unit' => 'year', 'price' => '5.19'])
+            ->checkout(new \DateTimeImmutable('2024-05-19 11:33:58', new \DateTimeZone('UTC')), billElapsedPeriods: true, maxNetAmount: '15.57');
+
+        $request = $this->sent[1]['request'];
+        $this->assertSame('PUT /api/v1/client/subscriptions/01JSUB/checkout', $request->getMethod() . ' ' . $request->getUri()->getPath());
+        $this->assertSame(['starts_at' => '2024-05-19T11:33:58+00:00', 'bill_elapsed_periods' => true, 'max_net_amount' => '15.57'], $this->sentJson(1));
+    }
+
+    public function test_a_float_ceiling_is_sent_with_two_decimals(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(200, $this->subscription(['active' => true]));
+
+        $this->owner()->appSubscriptions()->create(['name' => '.de TLD', 'unit' => 'year', 'price' => 19.99])
+            ->checkout('2024-05-19', true, 19.99 * 3);
+
+        $this->assertSame(['starts_at' => '2024-05-19', 'bill_elapsed_periods' => true, 'max_net_amount' => 59.97], $this->sentJson(1));
+    }
+
+    public function test_billing_elapsed_periods_needs_a_start_and_a_ceiling(): void
+    {
+        $this->respond(201, $this->subscription());
+        $subscription = $this->owner()->appSubscriptions()->create(['name' => '.de TLD', 'unit' => 'year', 'price' => '5.19']);
+
+        foreach ([[null, '10.00'], ['2024-05-19', null], ['', '10.00'], ['2024-05-19', '']] as [$startsAt, $maxNetAmount]) {
+            try {
+                $subscription->checkout($startsAt, billElapsedPeriods: true, maxNetAmount: $maxNetAmount);
+                $this->fail('Expected an InvalidArgumentException.');
+            } catch (InvalidArgumentException) {
+            }
+        }
+
+        $this->assertCount(1, $this->sent);
+    }
+
+    public function test_an_exceeded_ceiling_carries_the_net_amount(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(409, ['message' => 'The elapsed periods come to 20.76 net, more than 15.57.', 'error' => 'elapsed_amount_exceeded', 'net_amount' => '20.76']);
+
+        $subscription = $this->owner()->appSubscriptions()->create(['name' => '.de TLD', 'unit' => 'year', 'price' => '5.19']);
+
+        try {
+            $subscription->checkout('2024-05-19', billElapsedPeriods: true, maxNetAmount: '15.57');
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isConflict());
+            $this->assertSame('elapsed_amount_exceeded', $e->error);
+            $this->assertSame('20.76', $e->body()->net_amount);
+        }
+    }
+
     public function test_errors_carry_status_and_error_code(): void
     {
         $this->respond(409, ['message' => 'Product subscription has already been cancelled.', 'error' => 'already_cancelled']);
@@ -163,6 +258,99 @@ class AppSubscriptionsTest extends TestCase
         }
     }
 
+    public function test_a_subscription_starts_with_a_free_trial(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(200, $this->subscription(['active' => true, 'autorenew' => true, 'status' => 'trial', 'starts_at' => '2026-11-04T10:00:00+00:00', 'trial_ends_at' => date(DATE_ATOM, time() + 14 * 86400)]));
+
+        $subscription = $this->owner()->appSubscriptions()->create(['group' => 'team-1', 'name' => 'Pro', 'unit' => 'month', 'price' => '9.99', 'trial_days' => 14, 'trial_once' => true]);
+        $subscription->checkout();
+
+        $this->assertSame(['group' => 'team-1', 'name' => 'Pro', 'unit' => 'month', 'price' => '9.99', 'trial_days' => 14, 'trial_once' => true, 'user_id' => '01JUSER'], $this->sentJson(0));
+        $this->assertTrue($subscription->isTrial());
+        $this->assertTrue($subscription->isActive());
+    }
+
+    public function test_a_trial_can_be_confirmed_without_a_payment_method_and_end_cancelled(): void
+    {
+        $this->respond(201, $this->subscription(['trial_days' => 14, 'trial_payment_method' => 'optional']));
+        $this->respond(200, $this->subscription(['active' => false, 'cancelled' => true, 'status' => 'cancelled', 'starts_at' => '2026-11-04T10:00:00+00:00', 'trial_ends_at' => '2026-11-18T10:00:00+00:00', 'cancels_at' => '2026-11-18T10:00:00+00:00', 'trial_payment_method' => 'optional', 'cancellation_reason' => 'trial_ended_without_payment_method']));
+
+        $subscription = $this->owner()->appSubscriptions()->create(['name' => 'Pro', 'unit' => 'month', 'price' => '9.99', 'trial_days' => 14, 'trial_payment_method' => TrialPaymentMethod::OPTIONAL]);
+
+        $this->assertSame('optional', $this->sentJson(0)['trial_payment_method']);
+        $this->assertSame(TrialPaymentMethod::OPTIONAL, $subscription->trial_payment_method);
+
+        $ended = $this->owner()->appSubscriptions()->find('01JSUB');
+        $this->assertTrue($ended->isCancelled());
+        $this->assertSame(CancellationReason::TRIAL_ENDED_WITHOUT_PAYMENT_METHOD, $ended->cancellation_reason);
+    }
+
+    public function test_a_used_trial_is_refused_on_checkout(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(409, ['message' => 'The user already had a free trial.', 'error' => 'trial_already_used']);
+
+        $subscription = $this->owner()->appSubscriptions()->create(['name' => 'Pro', 'unit' => 'month', 'price' => '9.99', 'trial_ends_at' => '2026-12-01T00:00:00+01:00', 'trial_once' => true]);
+
+        try {
+            $subscription->checkout();
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isConflict());
+            $this->assertSame('trial_already_used', $e->error);
+        }
+    }
+
+    public function test_a_subscription_is_created_with_a_discount(): void
+    {
+        $discount = ['label' => 'SUMMER20', 'percent_off' => 20, 'duration' => 'repeating', 'duration_in_periods' => 3];
+        $this->respond(201, $this->subscription(['discount' => [...$discount, 'amount_off' => null, 'periods_remaining' => 3]]));
+
+        $subscription = $this->owner()->appSubscriptions()->create(['name' => 'Pro', 'unit' => 'month', 'price' => '9.99', 'discount' => $discount]);
+
+        $this->assertSame($discount, $this->sentJson(0)['discount']);
+        $this->assertSame('SUMMER20', $subscription->discount->label);
+        $this->assertSame(3, $subscription->discount->periods_remaining);
+    }
+
+    public function test_a_running_subscription_is_changed_now_or_at_the_period_end(): void
+    {
+        $change = ['applies_at' => '2026-12-01T00:00:00+00:00', 'name' => 'Pro', 'description' => null, 'unit' => 'month', 'price' => 14.99, 'discount' => null, 'created_at' => '2026-11-04T10:00:00+00:00'];
+        $this->respond(200, $this->subscription(['active' => true, 'price' => 14.99]));
+        $this->respond(200, $this->subscription(['active' => true, 'price' => 14.99, 'scheduled_change' => $change]));
+        $this->respond(200, $this->subscription(['active' => true, 'price' => 14.99, 'scheduled_change' => null]));
+
+        $subscription = new AppSubscription((object) $this->subscription(['active' => true])['data']);
+
+        $this->assertSame(14.99, $subscription->change(['apply' => AppSubscription::APPLY_NOW, 'price' => '14.99', 'discount' => null])->price);
+        $this->assertSame('2026-12-01T00:00:00+00:00', $subscription->change(['apply' => AppSubscription::APPLY_PERIOD_END, 'unit' => 'month', 'name' => 'Pro'])->scheduled_change->applies_at);
+        $this->assertNull($subscription->cancelScheduledChange()->scheduled_change);
+
+        $this->assertSame([
+            'PUT /api/v1/client/subscriptions/01JSUB/change Bearer app-token',
+            'PUT /api/v1/client/subscriptions/01JSUB/change Bearer app-token',
+            'DELETE /api/v1/client/subscriptions/01JSUB/change Bearer app-token',
+        ], array_map(fn ($entry) => $entry['request']->getMethod() . ' ' . $entry['request']->getUri()->getPath() . ' ' . $entry['request']->getHeaderLine('Authorization'), $this->sent));
+        $this->assertSame(['apply' => 'now', 'price' => '14.99', 'discount' => null], $this->sentJson(0));
+        $this->assertSame(['apply' => 'period_end', 'unit' => 'month', 'name' => 'Pro'], $this->sentJson(1));
+    }
+
+    public function test_a_refused_change_carries_its_error_code(): void
+    {
+        $this->respond(409, ['message' => 'The credit would exceed the open bill.', 'error' => 'credit_exceeds_bill']);
+
+        $subscription = new AppSubscription((object) $this->subscription(['active' => true])['data']);
+
+        try {
+            $subscription->change(['apply' => AppSubscription::APPLY_NOW, 'price' => '1.99']);
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isConflict());
+            $this->assertSame('credit_exceeds_bill', $e->error);
+        }
+    }
+
     public function test_a_missing_user_id_is_reported(): void
     {
         $this->expectException(InvalidArgumentException::class);

tests/Id/BillableModelTest.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\Billable;
+use Illuminate\Database\Eloquent\Model;
+
+class BillableModelTest extends TestCase
+{
+    public function test_cached_api_results_are_not_model_attributes(): void
+    {
+        $user = new class extends Model {
+            use Billable;
+
+            protected $guarded = [];
+
+            public function cacheAll(): void
+            {
+                foreach (['addresses', 'countries', 'defaultPaymentMethod', 'invoices', 'orders', 'paymentMethods', 'subscriptions', 'transactions', 'userData'] as $name) {
+                    $this->{$name.'Cache'} = 'cached';
+                }
+
+                $this->preferencesCache['global'] = 'cached';
+            }
+        };
+        $user->email = 'ada@example.com';
+
+        $user->cacheAll();
+
+        // save() would otherwise write them as columns ("no such column: ordersCache")
+        $this->assertSame(['email' => 'ada@example.com'], $user->getAttributes());
+    }
+}

tests/Id/CheckoutConfirmationTest.php

@@ -0,0 +1,105 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Billable;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Exceptions\ConfirmationRequiredException;
+use Illuminate\Database\Eloquent\Model;
+
+class CheckoutConfirmationTest extends TestCase
+{
+    private function owner(): Model
+    {
+        $owner = new class extends Model {
+            use Billable;
+
+            protected $guarded = [];
+        };
+        $owner->anikeen_id = '01JUSER';
+        $owner->anikeen_id_access_token = 'user-token';
+
+        return $owner;
+    }
+
+    public function test_a_draft_order_links_to_its_confirmation_with_the_return_url(): void
+    {
+        $this->respond(200, ['data' => []]); // orders() loads the list first
+        $this->respond(201, ['data' => ['id' => '01JORD', 'status' => 'draft', 'confirmation_url' => 'https://id.anikeen.com/checkout/orders/01JORD']]);
+
+        $order = $this->owner()->orders()->create(['billing_address_id' => '01JADDR', 'items' => []]);
+
+        $this->assertSame('https://id.anikeen.com/checkout/orders/01JORD', $order->confirmationUrl());
+        $this->assertSame(
+            'https://id.anikeen.com/checkout/orders/01JORD?return_url=https%3A%2F%2Fshop.test%2Fdone%3Fcart%3D1',
+            $order->confirmationUrl('https://shop.test/done?cart=1'),
+        );
+        $this->assertSame('POST /api/v1/orders', $this->sent[1]['request']->getMethod() . ' ' . $this->sent[1]['request']->getUri()->getPath());
+    }
+
+    public function test_checked_out_bookings_have_no_confirmation_url(): void
+    {
+        $this->respond(200, ['data' => []]);
+        $this->respond(201, ['data' => ['id' => '01JORD', 'status' => 'completed', 'confirmation_url' => null]]);
+
+        $this->assertNull($this->owner()->orders()->create([])->confirmationUrl('https://shop.test/done'));
+    }
+
+    public function test_checking_out_a_draft_as_a_third_party_app_points_to_the_confirmation(): void
+    {
+        $this->respond(200, ['data' => []]); // subscriptions() loads the list first
+        $this->respond(201, ['data' => ['id' => '01JSUB', 'active' => false, 'confirmation_url' => 'https://id.anikeen.com/checkout/subscriptions/01JSUB']]);
+        $this->respond(403, ['message' => 'The user has to confirm this on Anikeen ID.', 'error' => 'confirmation_required', 'confirmation_url' => 'https://id.anikeen.com/checkout/subscriptions/01JSUB']);
+
+        $subscription = $this->owner()->subscriptions()->create(['name' => 'Pro', 'unit' => 'month', 'price' => 4.99]);
+
+        try {
+            $subscription->checkout();
+            $this->fail('Expected a ConfirmationRequiredException.');
+        } catch (ConfirmationRequiredException $e) {
+            $this->assertSame(403, $e->getCode());
+            $this->assertSame('https://id.anikeen.com/checkout/subscriptions/01JSUB', $e->confirmationUrl);
+        }
+    }
+
+    public function test_a_trusted_app_lets_the_user_confirm_its_order(): void
+    {
+        $this->respond(201, ['data' => ['id' => '01JORD', 'status' => 'draft', 'group' => 'team-1', 'metadata' => ['topup' => '7'], 'expires_at' => '2026-11-05T10:00:00+00:00', 'confirmation_url' => 'https://id.anikeen.com/checkout/orders/01JORD']]);
+
+        $result = app(AnikeenId::class)->createOrderForUser('01JUSER', [
+            'group' => 'team-1',
+            'confirm' => true,
+            'return_url' => 'https://console.test/billing/topup',
+            'metadata' => ['topup' => '7'],
+            'items' => [['type' => 'digital', 'name' => 'Credit', 'unit' => 'onetime', 'units' => 1, 'gross_price' => '10.00']],
+        ]);
+
+        $this->assertSame('POST /api/v1/admin/orders Bearer app-token', $this->sent[0]['request']->getMethod() . ' ' . $this->sent[0]['request']->getUri()->getPath() . ' ' . $this->sent[0]['request']->getHeaderLine('Authorization'));
+        $this->assertTrue($this->sentJson(0)['confirm']);
+        $this->assertSame('https://console.test/billing/topup', $this->sentJson(0)['return_url']);
+        $this->assertSame(['topup' => '7'], $this->sentJson(0)['metadata']);
+        $this->assertSame('01JUSER', $this->sentJson(0)['user_id']);
+        $this->assertSame('https://id.anikeen.com/checkout/orders/01JORD', $result->data->confirmation_url);
+        $this->assertSame('7', $result->data->metadata->topup);
+    }
+
+    public function test_an_expired_confirmation_is_a_conflict(): void
+    {
+        $this->respond(200, ['data' => []]);
+        $this->respond(201, ['data' => ['id' => '01JORD', 'status' => 'draft', 'confirmation_url' => 'https://id.anikeen.com/checkout/orders/01JORD']]);
+        $this->respond(409, ['message' => 'The order was not confirmed in time.', 'error' => 'confirmation_expired']);
+
+        $order = $this->owner()->orders()->create(['confirm' => true, 'return_url' => 'https://shop.test/done', 'metadata' => ['cart' => 1], 'items' => []]);
+
+        $this->assertSame(['confirm' => true, 'return_url' => 'https://shop.test/done', 'metadata' => ['cart' => 1], 'items' => []], $this->sentJson(1));
+
+        try {
+            $order->checkout();
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isConflict());
+            $this->assertSame('confirmation_expired', $e->error);
+        }
+    }
+}

tests/Id/CheckoutSessionsTest.php

@@ -0,0 +1,192 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Billable;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Resources\AppCheckoutSession;
+use Anikeen\Id\Resources\AppSubscription;
+use Anikeen\Id\Resources\CheckoutSession;
+use Anikeen\Id\Webhooks\EventType;
+use Anikeen\Id\Webhooks\Webhook;
+use Illuminate\Database\Eloquent\Model;
+use InvalidArgumentException;
+
+class CheckoutSessionsTest extends TestCase
+{
+    private function owner(): Model
+    {
+        $owner = new class extends Model {
+            use Billable;
+
+            protected $guarded = [];
+        };
+        $owner->anikeen_id = '01JUSER';
+        $owner->anikeen_id_access_token = 'user-token';
+
+        return $owner;
+    }
+
+    private function sessionData(array $overrides = []): array
+    {
+        return ['data' => [
+            'object' => 'checkout_session',
+            'id' => '01JCS',
+            'user_id' => '01JUSER',
+            'status' => 'open',
+            'return_url' => 'https://console.test/builder/done',
+            'metadata' => ['cart' => '42'],
+            'confirmation_url' => 'https://id.anikeen.com/checkout/sessions/01JCS',
+            'subscription_ids' => ['01JS1', '01JS2'],
+            'subscriptions' => [
+                ['id' => '01JS1', 'user_id' => '01JUSER', 'name' => 'Cloud Server S', 'active' => false, 'payload' => ['product' => 'server-s']],
+                ['id' => '01JS2', 'user_id' => '01JUSER', 'name' => 'Backup', 'active' => false],
+            ],
+            ...$overrides,
+        ]];
+    }
+
+    private function request(int $index): string
+    {
+        $request = $this->sent[$index]['request'];
+
+        return $request->getMethod() . ' ' . $request->getUri()->getPath() . ' ' . $request->getHeaderLine('Authorization');
+    }
+
+    public function test_a_trusted_app_opens_a_session_with_its_own_token(): void
+    {
+        $this->respond(201, $this->sessionData());
+
+        $session = $this->owner()->appCheckoutSessions()->create([
+            'return_url' => 'https://console.test/builder/done',
+            'idempotency_key' => 'cart:42',
+            'subscriptions' => [
+                ['group' => 'team-1', 'name' => 'Cloud Server S', 'unit' => 'hour', 'price' => '0.0137', 'payload' => ['product' => 'server-s']],
+                ['id' => '01JS2'],
+            ],
+        ]);
+
+        $this->assertSame('POST /api/v1/client/checkout-sessions Bearer app-token', $this->request(0));
+        $this->assertSame('01JUSER', $this->sentJson(0)['user_id']);
+        $this->assertSame([['group' => 'team-1', 'name' => 'Cloud Server S', 'unit' => 'hour', 'price' => '0.0137', 'payload' => ['product' => 'server-s']], ['id' => '01JS2']], $this->sentJson(0)['subscriptions']);
+
+        $this->assertInstanceOf(AppCheckoutSession::class, $session);
+        $this->assertSame('https://id.anikeen.com/checkout/sessions/01JCS', $session->confirmationUrl());
+        $this->assertTrue($session->isOpen());
+        $this->assertSame(['01JS1', '01JS2'], $session->subscriptionIds());
+        $this->assertContainsOnlyInstancesOf(AppSubscription::class, $session->subscriptions());
+        $this->assertSame('server-s', $session->subscriptions()[0]->payload->product);
+        $this->assertSame('42', $session->metadata->cart);
+    }
+
+    public function test_the_app_finds_refreshes_and_cancels_sessions(): void
+    {
+        $this->respond(200, $this->sessionData(['status' => 'completed', 'confirmation_url' => null]));
+        $this->respond(200, $this->sessionData(['user_id' => 'someone-else']));
+        $this->respond(404, ['message' => 'Checkout session not found.', 'error' => 'checkout_session_not_found']);
+        $this->respond(200, $this->sessionData());
+        $this->respond(200, $this->sessionData(['status' => 'cancelled', 'confirmation_url' => null]));
+        $this->respond(409, ['message' => 'The checkout session is cancelled.', 'error' => 'checkout_session_cancelled']);
+
+        $sessions = $this->owner()->appCheckoutSessions();
+
+        $completed = $sessions->find('01JCS');
+        $this->assertTrue($completed->isCompleted());
+        $this->assertNull($completed->confirmationUrl());
+        $this->assertNull($sessions->find('01JCS'), 'another user\'s session');
+        $this->assertNull($sessions->find('unknown'));
+
+        $session = app(AnikeenId::class)->appCheckoutSessions()->find('01JCS'); // e.g. from a webhook
+        $session->cancel();
+        $this->assertTrue($session->isCancelled());
+        $this->assertSame('POST /api/v1/client/checkout-sessions/01JCS/cancel Bearer app-token', $this->request(4));
+
+        try {
+            $session->cancel();
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isConflict());
+            $this->assertSame('checkout_session_cancelled', $e->error);
+        }
+    }
+
+    public function test_without_a_billable_the_user_id_is_required(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        app(AnikeenId::class)->appCheckoutSessions()->create(['subscriptions' => [['id' => '01JS1']]]);
+    }
+
+    public function test_any_app_opens_a_session_with_the_users_token(): void
+    {
+        $this->respond(201, $this->sessionData());
+        $this->respond(200, $this->sessionData(['status' => 'expired', 'confirmation_url' => null]));
+        $this->respond(404, ['message' => 'Checkout session not found.', 'error' => 'checkout_session_not_found']);
+
+        $user = $this->owner();
+        $session = $user->checkoutSessions()->create(['subscriptions' => [['name' => 'Pro', 'unit' => 'month', 'price' => 4.99]]]);
+
+        $this->assertSame('POST /api/v1/checkout-sessions Bearer user-token', $this->request(0));
+        $this->assertArrayNotHasKey('user_id', $this->sentJson(0));
+        $this->assertInstanceOf(CheckoutSession::class, $session);
+        $this->assertSame('https://id.anikeen.com/checkout/sessions/01JCS', $session->confirmationUrl());
+        $this->assertSame(['01JS1', '01JS2'], $session->subscriptionIds());
+
+        $expired = $user->checkoutSessions()->find('01JCS');
+        $this->assertTrue($expired->isCancelled());
+        $this->assertSame(CheckoutSession::STATUS_EXPIRED, $expired->status);
+        $this->assertNull($user->checkoutSessions()->find('unknown'));
+    }
+
+    public function test_session_subscriptions_carry_a_free_trial(): void
+    {
+        $this->respond(201, $this->sessionData());
+
+        $this->owner()->appCheckoutSessions()->create(['subscriptions' => [
+            ['group' => 'team-1', 'name' => 'Pro', 'unit' => 'month', 'price' => '9.99', 'trial_days' => 14, 'trial_once' => true],
+            ['group' => 'team-1', 'name' => 'Backup', 'unit' => 'month', 'price' => '1.99', 'trial_ends_at' => '2026-12-01T00:00:00+00:00'],
+        ]]);
+
+        $this->assertSame(14, $this->sentJson(0)['subscriptions'][0]['trial_days']);
+        $this->assertTrue($this->sentJson(0)['subscriptions'][0]['trial_once']);
+        $this->assertSame('2026-12-01T00:00:00+00:00', $this->sentJson(0)['subscriptions'][1]['trial_ends_at']);
+    }
+
+    public function test_session_subscriptions_carry_a_discount(): void
+    {
+        $this->respond(201, $this->sessionData());
+
+        $this->owner()->checkoutSessions()->create(['subscriptions' => [
+            ['name' => 'Pro', 'unit' => 'month', 'price' => 4.99, 'discount' => ['label' => 'WELCOME', 'amount_off' => '1.00', 'duration' => 'once']],
+        ]]);
+
+        $this->assertSame('POST /api/v1/checkout-sessions Bearer user-token', $this->request(0));
+        $this->assertSame(['label' => 'WELCOME', 'amount_off' => '1.00', 'duration' => 'once'], $this->sentJson(0)['subscriptions'][0]['discount']);
+    }
+
+    public function test_nothing_is_requested_until_a_method_is_called(): void
+    {
+        $this->owner()->checkoutSessions();
+        $this->owner()->appCheckoutSessions();
+
+        $this->assertCount(0, $this->sent);
+    }
+
+    public function test_checkout_webhooks_carry_the_session(): void
+    {
+        $payload = json_encode(['id' => '01JEV', 'type' => 'checkout.completed', 'created' => time(), 'data' => ['object' => $this->sessionData(['status' => 'completed'])['data']]]);
+        $timestamp = time();
+        $signature = 't=' . $timestamp . ',v1=' . hash_hmac('sha256', "{$timestamp}.{$payload}", 'whsec_test');
+
+        $event = Webhook::constructEvent($payload, $signature, 'whsec_test');
+
+        $this->assertSame(EventType::CHECKOUT_COMPLETED, $event['type']);
+        $this->assertSame(['01JS1', '01JS2'], $event['data']['object']['subscription_ids']);
+        $this->assertContains('checkout.expired', EventType::all());
+        $this->assertContains('subscription.activated', EventType::all());
+        $this->assertContains('subscription.trial_will_end', EventType::all());
+        $this->assertContains('subscription.discount_ended', EventType::all());
+        $this->assertContains('subscription.updated', EventType::all());
+    }
+}

tests/Id/EndpointsTest.php

@@ -4,6 +4,7 @@ namespace Anikeen\Id\Tests;
 
 use Anikeen\Id\AnikeenId;
 use Anikeen\Id\Billable;
+use Anikeen\Id\Exceptions\ApiException;
 use Illuminate\Database\Eloquent\Model;
 
 /**
@@ -54,6 +55,36 @@ class EndpointsTest extends TestCase
         $this->assertSame('GET /api/v1/billing Bearer user-token', $this->sentCall(0));
     }
 
+    public function test_billing_overview_carries_the_billing_limit(): void
+    {
+        $this->respond(200, ['data' => ['current_charges' => 11.9, 'billing_limit' => ['object' => 'billing_limit', 'limit' => '50.00', 'used' => '11.90', 'remaining' => '38.10', 'reached' => false, 'version' => 3]]]);
+
+        $limit = new \Anikeen\Id\Resources\BillingLimit($this->owner()->billingOverview()->billing_limit);
+
+        $this->assertSame('38.10', $limit->remaining());
+        $this->assertTrue($limit->allows('38.10'));
+        $this->assertNull($limit->usedByApp());
+    }
+
+    public function test_charges_and_billing_limits_of_users_use_the_app_token(): void
+    {
+        $charge = ['data' => ['object' => 'charge', 'id' => '01JCHARGE', 'status' => 'open']];
+        $this->respond(201, $charge);
+        $this->respond(200, $charge);
+        $this->respond(200, $charge);
+        $this->respond(200, ['data' => ['object' => 'billing_limit', 'limit' => null]]);
+
+        app(AnikeenId::class)->createChargeForUser('01JUSER', ['idempotency_key' => 'k', 'name' => 'Card', 'quantity' => 1, 'unit_price' => '4.00']);
+        app(AnikeenId::class)->findChargeForUser('01JUSER', '01JCHARGE');
+        app(AnikeenId::class)->voidChargeForUser('01JUSER', '01JCHARGE');
+        app(AnikeenId::class)->billingLimitForUser('01JUSER');
+
+        $this->assertSame('POST /api/v1/client/users/01JUSER/charges Bearer app-token', $this->sentCall(0));
+        $this->assertSame('GET /api/v1/client/users/01JUSER/charges/01JCHARGE Bearer app-token', $this->sentCall(1));
+        $this->assertSame('POST /api/v1/client/users/01JUSER/charges/01JCHARGE/void Bearer app-token', $this->sentCall(2));
+        $this->assertSame('GET /api/v1/client/users/01JUSER/billing-limit Bearer app-token', $this->sentCall(3));
+    }
+
     public function test_invoice_download_url_is_read_not_updated(): void
     {
         $this->respond(200, $this->list([['id' => 'inv1']]));
@@ -90,6 +121,52 @@ class EndpointsTest extends TestCase
         $this->assertSame(['email' => 'erika@example.com', 'password' => 'secret-123', 'name' => 'Erika Mustermann', 'password_confirmation' => 'secret-123'], $this->sentJson(0));
     }
 
+    public function test_create_user_can_send_an_invitation(): void
+    {
+        $this->respond(201, ['data' => ['id' => '01JNEW', 'email' => 'erika@example.com', 'created' => true, 'invitation_sent' => true]]);
+
+        $result = app(AnikeenId::class)->createUser(['name' => 'Erika Mustermann', 'email' => 'erika@example.com', 'send_invitation' => true]);
+
+        $this->assertSame('POST /api/v1/admin/users Bearer app-token', $this->sentCall(0));
+        $this->assertSame(['name' => 'Erika Mustermann', 'email' => 'erika@example.com', 'send_invitation' => true], $this->sentJson(0));
+        $this->assertTrue($result->data->created);
+        $this->assertTrue($result->data->invitation_sent);
+    }
+
+    public function test_find_user_by_email_uses_the_lookup_endpoint(): void
+    {
+        $this->respond(200, ['data' => ['id' => '01JUSER', 'name' => 'Erika', 'email' => 'erika@example.com', 'email_verified' => true, 'has_billing_address' => false]]);
+
+        $result = app(AnikeenId::class)->findUserByEmail('Erika@Example.com');
+
+        $this->assertSame('POST /api/v1/admin/users/lookup Bearer app-token', $this->sentCall(0));
+        $this->assertSame(['email' => 'Erika@Example.com'], $this->sentJson(0));
+        $this->assertSame('01JUSER', $result->data->id);
+        $this->assertFalse($result->data->has_billing_address);
+    }
+
+    public function test_find_user_by_email_returns_null_without_an_account(): void
+    {
+        $this->respond(404, ['message' => 'User not found.', 'error' => 'user_not_found']);
+
+        $this->assertNull(app(AnikeenId::class)->findUserByEmail('nobody@example.com'));
+    }
+
+    public function test_find_user_by_email_throws_other_failures(): void
+    {
+        $this->respond(404, ['message' => 'Not found.']); // e.g. an Anikeen ID without the lookup
+        $this->respond(500, ['message' => 'Server Error']);
+
+        foreach ([404, 500] as $status) {
+            try {
+                app(AnikeenId::class)->findUserByEmail('erika@example.com');
+                $this->fail('Expected an ApiException.');
+            } catch (ApiException $e) {
+                $this->assertSame($status, $e->status);
+            }
+        }
+    }
+
     public function test_email_check_and_socialite_users(): void
     {
         $this->respond(200, ['data' => ['exists' => true]]);
@@ -199,6 +276,35 @@ class EndpointsTest extends TestCase
         $this->assertSame('POST /api/v1/admin/transactions Bearer app-token', $this->sentCall(1));
     }
 
+    public function test_billing_portal_links_for_users_use_the_app_token(): void
+    {
+        $link = ['object' => 'billing_portal_link', 'url' => 'https://id.test/billing/portal/01JUSER?signature=x', 'user_id' => '01JUSER', 'flow' => 'invoices', 'group' => 'team-1', 'return_url' => 'https://console.test/billing', 'expires_at' => '2026-11-04T10:15:00+00:00'];
+        $this->respond(201, ['data' => $link]);
+        $this->respond(201, ['data' => $link]);
+
+        $created = app(AnikeenId::class)->createBillingPortalLinkForUser('01JUSER', ['return_url' => 'https://console.test/billing', 'group' => 'team-1', 'flow' => 'invoices']);
+        $url = $this->owner()->appBillingPortalUrl(['flow' => 'payment_method_update']);
+
+        $this->assertSame('billing_portal_link', $created->object);
+        $this->assertSame($link['url'], $url);
+        $this->assertSame('POST /api/v1/client/users/01JUSER/billing-portal Bearer app-token', $this->sentCall(0));
+        $this->assertSame(['return_url' => 'https://console.test/billing', 'group' => 'team-1', 'flow' => 'invoices'], $this->sentJson(0));
+        $this->assertSame('POST /api/v1/client/users/01JUSER/billing-portal Bearer app-token', $this->sentCall(1));
+        $this->assertSame(['flow' => 'payment_method_update'], $this->sentJson(1));
+    }
+
+    public function test_a_refused_billing_portal_link_is_an_api_exception(): void
+    {
+        $this->respond(422, ['message' => 'The return URL has to point to one of the app\'s redirect URIs.', 'errors' => ['return_url' => ['…']]]);
+
+        try {
+            $this->owner()->appBillingPortalUrl(['return_url' => 'https://elsewhere.test']);
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertSame(422, $e->status);
+        }
+    }
+
     public function test_order_preview_maps_the_country_into_the_billing_address(): void
     {
         $this->respond(200, ['data' => ['gross_total' => 11.9]]);
@@ -207,4 +313,133 @@ class EndpointsTest extends TestCase
 
         $this->assertSame(['items' => [], 'billing_address' => ['country_iso' => 'DE']], $this->sentJson(0));
     }
+
+    private function preference(string $namespace, string $key, mixed $value, int $version = 7): array
+    {
+        return ['namespace' => $namespace, 'key' => $key, 'value' => $value, 'version' => $version, 'updated_at' => '2026-11-06T10:00:00.000000Z', 'updated_by' => ['type' => 'app', 'client_id' => 'app-client']];
+    }
+
+    private function conditions(int $index): array
+    {
+        $request = $this->sent[$index]['request'];
+
+        return [$request->getHeaderLine('If-Match'), $request->getHeaderLine('If-None-Match')];
+    }
+
+    public function test_global_preferences_of_the_user(): void
+    {
+        $this->respond(200, ['data' => [$this->preference('global', 'appearance', 'dark')]]);
+
+        $preferences = $this->owner()->globalPreferences();
+
+        $this->assertSame('dark', $preferences->get('appearance'));
+        $this->assertSame('GET /api/v1/preferences/global Bearer user-token', $this->sentCall(0));
+    }
+
+    public function test_global_preference_with_a_default(): void
+    {
+        $this->respond(200, ['data' => [$this->preference('global', 'appearance', 'light')]]);
+
+        $owner = $this->owner();
+
+        $this->assertSame('light', $owner->globalPreference('appearance'));
+        $this->assertSame('system', $owner->globalPreference('unknown', 'system'));
+        $this->assertCount(1, $this->sent);
+        $this->assertSame('GET /api/v1/preferences/global Bearer user-token', $this->sentCall(0));
+    }
+
+    public function test_set_global_preference(): void
+    {
+        $this->respond(201, ['data' => $this->preference('global', 'appearance', 'dark', 8)]);
+        $this->respond(200, ['data' => $this->preference('global', 'appearance', 'light', 9)]);
+
+        $created = $this->owner()->setGlobalPreference('appearance', 'dark');
+        $updated = $this->owner()->setGlobalPreference('appearance', 'light', ifVersion: 8);
+
+        $this->assertTrue($created->wasCreated());
+        $this->assertFalse($updated->wasCreated());
+        $this->assertSame(9, $updated->version);
+        $this->assertSame('PUT /api/v1/preferences/global/appearance Bearer user-token', $this->sentCall(0));
+        $this->assertSame(['value' => 'dark'], $this->sentJson(0));
+        $this->assertSame(['', ''], $this->conditions(0));
+        $this->assertSame(['"8"', ''], $this->conditions(1));
+    }
+
+    public function test_delete_global_preference(): void
+    {
+        $this->respond(204);
+        $this->respond(204);
+
+        $this->owner()->deleteGlobalPreference('appearance');
+        $this->owner()->deleteGlobalPreference('appearance', ifVersion: 9);
+
+        $this->assertSame('DELETE /api/v1/preferences/global/appearance Bearer user-token', $this->sentCall(0));
+        $this->assertSame('', (string) $this->sent[0]['request']->getBody());
+        $this->assertSame(['', ''], $this->conditions(0));
+        $this->assertSame(['"9"', ''], $this->conditions(1));
+    }
+
+    public function test_preferences_by_user_id(): void
+    {
+        $this->respond(200, ['data' => [$this->preference('acme', 'plan', 'pro'), $this->preference('acme', 'theme', ['accent' => 'blue'])]]);
+
+        $preferences = app(AnikeenId::class)->preferencesByUserId('01JUSER', 'acme');
+
+        $this->assertEquals(['plan' => 'pro', 'theme' => (object) ['accent' => 'blue']], $preferences->values());
+        $this->assertSame('blue', $preferences->find('theme')->value->accent);
+        $this->assertNull($preferences->find('missing'));
+        $this->assertSame('GET /api/v1/client/users/01JUSER/preferences/acme Bearer app-token', $this->sentCall(0));
+    }
+
+    public function test_preference_by_user_id(): void
+    {
+        $this->respond(200, ['data' => $this->preference('acme', 'plan', 'pro')]);
+
+        $preference = app(AnikeenId::class)->preferenceByUserId('01JUSER', 'acme', 'plan');
+
+        $this->assertSame('pro', $preference->value);
+        $this->assertSame(7, $preference->version);
+        $this->assertSame('GET /api/v1/client/users/01JUSER/preferences/acme/plan Bearer app-token', $this->sentCall(0));
+    }
+
+    public function test_set_preference_by_user_id(): void
+    {
+        $this->respond(200, ['data' => $this->preference('acme', 'plan', 'pro')]);
+        $this->respond(200, ['data' => $this->preference('acme', 'plan', 'pro')]);
+        $this->respond(201, ['data' => $this->preference('acme', 'plan', 'pro')]);
+
+        $anikeenId = app(AnikeenId::class);
+        $anikeenId->setPreferenceByUserId('01JUSER', 'acme', 'plan', 'pro');
+        $anikeenId->setPreferenceByUserId('01JUSER', 'acme', 'plan', 'pro', ifVersion: 7);
+        $anikeenId->setPreferenceByUserId('01JUSER', 'acme', 'plan', 'pro', createOnly: true);
+
+        $this->assertSame('PUT /api/v1/client/users/01JUSER/preferences/acme/plan Bearer app-token', $this->sentCall(0));
+        $this->assertSame(['value' => 'pro'], $this->sentJson(0));
+        $this->assertSame(['', ''], $this->conditions(0));
+        $this->assertSame(['"7"', ''], $this->conditions(1));
+        $this->assertSame(['', '*'], $this->conditions(2));
+    }
+
+    public function test_delete_preference_by_user_id(): void
+    {
+        $this->respond(204);
+        $this->respond(204);
+
+        app(AnikeenId::class)->deletePreferenceByUserId('01JUSER', 'acme', 'plan');
+        app(AnikeenId::class)->deletePreferenceByUserId('01JUSER', 'acme', 'plan', ifVersion: 7);
+
+        $this->assertSame('DELETE /api/v1/client/users/01JUSER/preferences/acme/plan Bearer app-token', $this->sentCall(0));
+        $this->assertSame(['', ''], $this->conditions(0));
+        $this->assertSame(['"7"', ''], $this->conditions(1));
+    }
+
+    public function test_find_user_id_by_preference(): void
+    {
+        $this->respond(200, ['data' => ['user_id' => '01JUSER', 'namespace' => 'acme', 'key' => 'customer_id', 'version' => 7, 'updated_at' => '2026-11-06T10:00:00.000000Z']]);
+
+        $this->assertSame('01JUSER', app(AnikeenId::class)->findUserIdByPreference('acme', 'customer_id', 'cus_123'));
+        $this->assertSame('POST /api/v1/client/preferences/acme/lookup Bearer app-token', $this->sentCall(0));
+        $this->assertSame(['key' => 'customer_id', 'value' => 'cus_123'], $this->sentJson(0));
+        $this->assertSame('', $this->sent[0]['request']->getUri()->getQuery());
+    }
 }

tests/Id/PreferencesTest.php

@@ -0,0 +1,226 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Billable;
+use Anikeen\Id\Enums\Appearance;
+use Anikeen\Id\Enums\SharedPreference;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Exceptions\PreconditionFailedException;
+use Illuminate\Database\Eloquent\Model;
+use InvalidArgumentException;
+
+class PreferencesTest extends TestCase
+{
+    private function owner(): Model
+    {
+        $owner = new class extends Model {
+            use Billable;
+
+            protected $guarded = [];
+        };
+        $owner->anikeen_id = '01JUSER';
+        $owner->anikeen_id_access_token = 'user-token';
+
+        return $owner;
+    }
+
+    private function preference(string $key, mixed $value, int $version = 7): array
+    {
+        return ['data' => ['namespace' => 'global', 'key' => $key, 'value' => $value, 'version' => $version, 'updated_at' => '2026-11-06T10:00:00.000000Z', 'updated_by' => ['type' => 'user', 'client_id' => 'app-client']]];
+    }
+
+    private function path(int $index): string
+    {
+        return $this->sent[$index]['request']->getUri()->getPath();
+    }
+
+    public function test_the_lookup_returns_null_when_nobody_holds_the_value(): void
+    {
+        $this->respond(404, ['message' => 'The preference is not set.', 'error' => 'preference_not_found']);
+
+        $this->assertNull(app(AnikeenId::class)->findUserIdByPreference('acme', 'customer_id', 'cus_123'));
+    }
+
+    public function test_the_lookup_throws_on_other_not_found_answers(): void
+    {
+        $this->respond(404, ['message' => 'The namespace does not exist.', 'error' => 'namespace_not_found']);
+
+        try {
+            app(AnikeenId::class)->findUserIdByPreference('acme', 'customer_id', 'cus_123');
+            $this->fail('no exception');
+        } catch (ApiException $e) {
+            $this->assertSame(404, $e->status);
+            $this->assertSame('namespace_not_found', $e->error);
+        }
+    }
+
+    public function test_the_lookup_throws_on_a_404_without_an_error_code(): void
+    {
+        $this->respond(404, ['message' => 'Not Found']);
+
+        $this->expectException(ApiException::class);
+
+        app(AnikeenId::class)->findUserIdByPreference('acme', 'customer_id', 'cus_123');
+    }
+
+    public function test_the_lookup_throws_on_validation_errors(): void
+    {
+        $this->respond(422, ['message' => 'The key is not unique.', 'error' => 'key_not_unique']);
+
+        try {
+            app(AnikeenId::class)->findUserIdByPreference('acme', 'plan', 'pro');
+            $this->fail('no exception');
+        } catch (ApiException $e) {
+            $this->assertSame('key_not_unique', $e->error);
+        }
+    }
+
+    public function test_a_failed_app_write_carries_the_current_version(): void
+    {
+        $this->respond(412, ['message' => 'The preference has another version.', 'error' => 'preference_version_mismatch', 'current_version' => 12]);
+
+        try {
+            app(AnikeenId::class)->setPreferenceByUserId('01JUSER', 'acme', 'plan', 'pro', ifVersion: 7);
+            $this->fail('no exception');
+        } catch (PreconditionFailedException $e) {
+            $this->assertSame(412, $e->status);
+            $this->assertSame('preference_version_mismatch', $e->error);
+            $this->assertSame(12, $e->currentVersion());
+        }
+    }
+
+    public function test_a_create_only_write_of_a_set_key_fails(): void
+    {
+        $this->respond(412, ['message' => 'The preference is already set.', 'error' => 'preference_exists', 'current_version' => 3]);
+
+        try {
+            app(AnikeenId::class)->setPreferenceByUserId('01JUSER', 'acme', 'plan', 'pro', createOnly: true);
+            $this->fail('no exception');
+        } catch (PreconditionFailedException $e) {
+            $this->assertSame('preference_exists', $e->error);
+            $this->assertSame(3, $e->currentVersion());
+        }
+    }
+
+    public function test_a_failed_user_write_carries_the_current_version(): void
+    {
+        $this->respond(412, ['message' => 'The preference has another version.', 'error' => 'preference_version_mismatch', 'current_version' => null]);
+        $this->respond(412, ['message' => 'The preference has another version.', 'error' => 'preference_version_mismatch', 'current_version' => 5]);
+
+        foreach ([
+            fn () => $this->owner()->setGlobalPreference('appearance', 'dark', ifVersion: 4),
+            fn () => $this->owner()->deleteGlobalPreference('appearance', ifVersion: 4),
+        ] as $i => $call) {
+            try {
+                $call();
+                $this->fail('no exception');
+            } catch (PreconditionFailedException $e) {
+                $this->assertSame([null, 5][$i], $e->currentVersion());
+            }
+        }
+    }
+
+    public function test_a_write_is_either_conditional_or_create_only(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        try {
+            app(AnikeenId::class)->setPreferenceByUserId('01JUSER', 'acme', 'plan', 'pro', ifVersion: 7, createOnly: true);
+        } finally {
+            $this->assertCount(0, $this->sent);
+        }
+    }
+
+    public function test_writes_clear_the_cached_preferences(): void
+    {
+        $owner = $this->owner();
+
+        $this->respond(200, ['data' => [$this->preference('appearance', 'light')['data']]]);
+        $this->respond(200, $this->preference('appearance', 'dark', 8));
+        $this->respond(200, ['data' => [$this->preference('appearance', 'dark', 8)['data']]]);
+        $this->respond(204);
+        $this->respond(200, ['data' => []]);
+
+        $this->assertSame('light', $owner->globalPreference(SharedPreference::APPEARANCE));
+        $this->assertSame('light', $owner->globalPreference(SharedPreference::APPEARANCE)); // cached
+        $owner->setGlobalPreference(SharedPreference::APPEARANCE, Appearance::DARK);
+        $this->assertSame('dark', $owner->globalPreference(SharedPreference::APPEARANCE));
+        $owner->deleteGlobalPreference(SharedPreference::APPEARANCE);
+        $this->assertSame(Appearance::SYSTEM, $owner->globalPreference(SharedPreference::APPEARANCE, Appearance::SYSTEM));
+
+        $this->assertCount(5, $this->sent);
+        $this->assertSame(['GET', 'PUT', 'GET', 'DELETE', 'GET'], array_map(fn ($sent) => $sent['request']->getMethod(), $this->sent));
+    }
+
+    public function test_a_failed_write_clears_the_cached_preferences_too(): void
+    {
+        $owner = $this->owner();
+
+        $this->respond(200, ['data' => [$this->preference('appearance', 'light')['data']]]);
+        $this->respond(412, ['message' => 'x', 'error' => 'preference_version_mismatch', 'current_version' => 9]);
+        $this->respond(200, ['data' => [$this->preference('appearance', 'dark', 9)['data']]]);
+
+        $owner->globalPreferences();
+
+        try {
+            $owner->setGlobalPreference('appearance', 'dark', ifVersion: 7);
+        } catch (PreconditionFailedException) {
+        }
+
+        $this->assertSame('dark', $owner->globalPreference('appearance'));
+        $this->assertCount(3, $this->sent);
+    }
+
+    public function test_path_segments_are_encoded(): void
+    {
+        $this->respond(200, ['data' => []]);
+        $this->respond(204);
+        $this->respond(200, ['data' => ['user_id' => '01JUSER']]);
+
+        $anikeenId = app(AnikeenId::class);
+        $anikeenId->preferencesByUserId('a/b', 'x y');
+        $anikeenId->deletePreferenceByUserId('01JUSER', 'acme', '../key?');
+        $anikeenId->findUserIdByPreference('ac/me', 'k', 'v');
+
+        $this->assertSame('/api/v1/client/users/a%2Fb/preferences/x%20y', $this->path(0));
+        $this->assertSame('/api/v1/client/users/01JUSER/preferences/acme/..%2Fkey%3F', $this->path(1));
+        $this->assertSame('/api/v1/client/preferences/ac%2Fme/lookup', $this->path(2));
+    }
+
+    public function test_values_round_trip_as_json(): void
+    {
+        $this->respond(201, $this->preference('settings', (object) []));
+
+        $preference = app(AnikeenId::class)->setPreferenceByUserId('01JUSER', 'acme', 'settings', (object) []);
+
+        $this->assertSame('{"value":{}}', (string) $this->sent[0]['request']->getBody());
+        $this->assertEquals((object) [], $preference->value);
+    }
+
+    public function test_a_deleted_user_is_not_found(): void
+    {
+        $this->respond(404, ['message' => 'The user does not exist.', 'error' => 'user_not_found']);
+
+        try {
+            app(AnikeenId::class)->preferenceByUserId('01JGONE', 'acme', 'plan');
+            $this->fail('no exception');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isNotFound());
+            $this->assertSame('user_not_found', $e->error);
+        }
+    }
+
+    public function test_an_unreachable_service_is_temporary(): void
+    {
+        $this->http->append(new \GuzzleHttp\Exception\ConnectException('down', new \GuzzleHttp\Psr7\Request('DELETE', 'x')));
+
+        try {
+            $this->owner()->deleteGlobalPreference('appearance');
+            $this->fail('no exception');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isTemporary());
+        }
+    }
+}

tests/Id/RequestHeadersTest.php

@@ -0,0 +1,113 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Exceptions\CollectionException;
+use Anikeen\Id\Exceptions\PreconditionFailedException;
+use Anikeen\Id\Resources\SshKeys;
+use Anikeen\Id\Support\AppRequest;
+
+class RequestHeadersTest extends TestCase
+{
+    public function test_requests_without_extra_headers_send_the_same_headers_as_before(): void
+    {
+        $this->respond(200, ['data' => []]);
+
+        AppRequest::send('GET', 'v1/client/subscriptions', null, ['page' => 1]);
+
+        $request = $this->sent[0]['request'];
+        $this->assertSame(['Bearer app-token'], $request->getHeader('Authorization'));
+        $this->assertSame(['app-client'], $request->getHeader('Client-ID'));
+        $this->assertFalse($request->hasHeader('If-Match'));
+        $this->assertFalse($request->hasHeader('If-None-Match'));
+        $this->assertSame('page=1', $request->getUri()->getQuery());
+    }
+
+    public function test_app_requests_send_extra_headers_also_on_the_retry_with_a_fresh_token(): void
+    {
+        $this->respond(401, ['message' => 'Unauthenticated.']);
+        $this->respond(200, ['data' => []]);
+
+        AppRequest::send('PUT', 'v1/x', ['value' => 1], [], ['If-Match' => '"7"']);
+
+        $this->assertSame('"7"', $this->sent[0]['request']->getHeaderLine('If-Match'));
+        $this->assertSame('"7"', $this->sent[1]['request']->getHeaderLine('If-Match'));
+        $this->assertSame('Bearer fresh-app-token', $this->sent[1]['request']->getHeaderLine('Authorization'));
+    }
+
+    public function test_extra_headers_do_not_replace_the_client_and_token_headers(): void
+    {
+        $this->respond(200, ['data' => []]);
+
+        app(AnikeenId::class)->withToken('user-token')
+            ->put('v1/x', ['value' => 1], [], null, ['If-None-Match' => '*', 'Authorization' => 'Bearer other']);
+
+        $request = $this->sent[0]['request'];
+        $this->assertSame('*', $request->getHeaderLine('If-None-Match'));
+        $this->assertSame('Bearer user-token', $request->getHeaderLine('Authorization'));
+    }
+
+    public function test_get_and_delete_helpers_take_headers(): void
+    {
+        $this->respond(200, ['data' => []]);
+        $this->respond(204);
+
+        $anikeenId = app(AnikeenId::class)->withToken('user-token');
+        $anikeenId->get('v1/x', [], null, ['If-None-Match' => '"3"']);
+        $anikeenId->delete('v1/x', [], [], null, ['If-Match' => '"3"']);
+
+        $this->assertSame('"3"', $this->sent[0]['request']->getHeaderLine('If-None-Match'));
+        $this->assertSame('"3"', $this->sent[1]['request']->getHeaderLine('If-Match'));
+    }
+
+    public function test_a_412_of_an_app_request_is_a_precondition_failed_exception(): void
+    {
+        $this->respond(412, ['message' => 'The preference has another version.', 'error' => 'preference_version_mismatch', 'current_version' => 12]);
+
+        try {
+            AppRequest::send('PUT', 'v1/x', ['value' => 1], [], ['If-Match' => '"7"']);
+            $this->fail('no exception');
+        } catch (PreconditionFailedException $e) {
+            $this->assertSame(412, $e->status);
+            $this->assertSame('preference_version_mismatch', $e->error);
+            $this->assertSame(12, $e->currentVersion());
+        }
+    }
+
+    public function test_a_412_of_a_user_request_is_a_precondition_failed_exception(): void
+    {
+        $this->respond(412, ['message' => 'The preference is already set.', 'error' => 'preference_exists', 'current_version' => null]);
+
+        $result = app(AnikeenId::class)->withToken('user-token')->put('v1/x', ['value' => 1]);
+        $e = ApiException::fromResult($result);
+
+        $this->assertInstanceOf(PreconditionFailedException::class, $e);
+        $this->assertSame('preference_exists', $e->error);
+        $this->assertNull($e->currentVersion());
+    }
+
+    public function test_list_errors_keep_their_collection_exception_type(): void
+    {
+        $this->respond(412, ['message' => 'x', 'error' => 'x']);
+
+        $this->expectException(CollectionException::class);
+
+        $anikeenId = app(AnikeenId::class)->withToken('user-token');
+        SshKeys::builder(fn () => $anikeenId->get('v1/ssh-keys'));
+    }
+
+    public function test_other_errors_stay_plain_api_exceptions(): void
+    {
+        $this->respond(409, ['message' => 'Taken.', 'error' => 'preference_value_taken']);
+
+        try {
+            AppRequest::send('PUT', 'v1/x', ['value' => 1]);
+            $this->fail('no exception');
+        } catch (ApiException $e) {
+            $this->assertSame(ApiException::class, $e::class);
+            $this->assertTrue($e->isConflict());
+        }
+    }
+}

tests/Id/ScopeTest.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\Enums\Scope;
+use PHPUnit\Framework\Attributes\DataProvider;
+use ReflectionClass;
+
+class ScopeTest extends TestCase
+{
+    public static function newScopes(): array
+    {
+        return [
+            'products:read' => [Scope::PRODUCTS_READ, 'products:read'],
+            'reseller-customers' => [Scope::RESELLER_CUSTOMERS, 'reseller-customers'],
+            'reseller-customers:read' => [Scope::RESELLER_CUSTOMERS_READ, 'reseller-customers:read'],
+            'reseller-grants' => [Scope::RESELLER_GRANTS, 'reseller-grants'],
+            'reseller-orders' => [Scope::RESELLER_ORDERS, 'reseller-orders'],
+        ];
+    }
+
+    #[DataProvider('newScopes')]
+    public function test_the_product_and_reseller_scopes_have_their_names(string $constant, string $expected): void
+    {
+        $this->assertSame($expected, $constant);
+    }
+
+    public function test_the_preference_scopes_match_anikeen_id(): void
+    {
+        $this->assertSame('preferences', Scope::PREFERENCES);
+        $this->assertSame('preferences:read', Scope::PREFERENCES_READ);
+        $this->assertSame('preferences:client', Scope::PREFERENCES_CLIENT);
+    }
+
+    public function test_there_is_no_full_products_scope_the_console_would_not_accept(): void
+    {
+        // the Console's product APIs accept `user`, `user:read` and `products:read` only
+        $this->assertNotContains('products', (new ReflectionClass(Scope::class))->getConstants());
+    }
+
+    public function test_every_scope_follows_the_resource_and_level_schema(): void
+    {
+        $scopes = array_values((new ReflectionClass(Scope::class))->getConstants());
+
+        $this->assertSame($scopes, array_values(array_unique($scopes)), 'scope values must be unique');
+
+        foreach ($scopes as $scope) {
+            // "resource" (full access), "resource:read" or "resource:client"; Anikeen ID groups by resource
+            $this->assertMatchesRegularExpression('/^[a-z]+(-[a-z]+)*(:(read|client))?$/', $scope);
+        }
+    }
+
+    public function test_each_reseller_resource_is_its_own_group(): void
+    {
+        $groups = collect((new ReflectionClass(Scope::class))->getConstants())
+            ->filter(fn (string $scope) => str_starts_with($scope, 'reseller-'))
+            ->groupBy(fn (string $scope) => explode(':', $scope)[0])
+            ->map(fn ($scopes) => $scopes->sort()->values()->all())
+            ->all();
+
+        $this->assertSame([
+            'reseller-customers' => ['reseller-customers', 'reseller-customers:read'],
+            'reseller-grants' => ['reseller-grants'],
+            'reseller-orders' => ['reseller-orders'],
+        ], $groups);
+    }
+}

tests/Id/SharedPreferenceTest.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\Enums\Appearance;
+use Anikeen\Id\Enums\SharedPreference;
+
+class SharedPreferenceTest extends TestCase
+{
+    public function test_the_shared_keys_and_values_match_anikeen_id(): void
+    {
+        $this->assertSame('global', SharedPreference::NAMESPACE);
+        $this->assertSame('appearance', SharedPreference::APPEARANCE);
+        $this->assertSame(['system', 'light', 'dark'], Appearance::all());
+    }
+}

tests/Id/ShipmentsTest.php

@@ -0,0 +1,88 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\Billable;
+use Anikeen\Id\Exceptions\ResourceException;
+use GuzzleHttp\Psr7\Response;
+use Illuminate\Database\Eloquent\Model;
+
+class ShipmentsTest extends TestCase
+{
+    private function owner(): Model
+    {
+        $owner = new class extends Model {
+            use Billable;
+
+            protected $guarded = [];
+        };
+        $owner->anikeen_id = '01JUSER';
+        $owner->anikeen_id_access_token = 'user-token';
+
+        return $owner;
+    }
+
+    private function order(): \Anikeen\Id\Resources\Order
+    {
+        $this->respond(200, ['data' => [], 'meta' => ['current_page' => 1, 'last_page' => 1, 'total' => 0], 'links' => ['next' => null]]);
+        $this->respond(200, ['data' => ['id' => 'ord1', 'status' => 'completed']]);
+
+        return $this->owner()->orders()->find('ord1');
+    }
+
+    private function sentCall(int $index): string
+    {
+        $request = $this->sent[$index]['request'];
+
+        return $request->getMethod() . ' ' . $request->getUri()->getPath() . ' ' . $request->getHeaderLine('Authorization');
+    }
+
+    public function test_an_order_is_shipped_with_carrier_tracking_and_items(): void
+    {
+        $order = $this->order();
+        $this->respond(200, ['data' => []]);
+        $this->respond(201, ['data' => ['id' => 'shp1', 'number' => 'LS-2026-0001', 'order_id' => 'ord1', 'carrier' => 'DHL']]);
+
+        $shipment = $order->shipments()->create([
+            'carrier' => 'DHL',
+            'tracking_number' => '0034',
+            'items' => [['order_item_id' => 'item1', 'units' => 1]],
+        ]);
+
+        $this->assertSame('LS-2026-0001', $shipment->number);
+        $this->assertSame('GET /api/v1/orders/ord1/shipments Bearer user-token', $this->sentCall(2));
+        $this->assertSame('POST /api/v1/orders/ord1/shipments Bearer user-token', $this->sentCall(3));
+        $this->assertSame(['carrier' => 'DHL', 'tracking_number' => '0034', 'items' => [['order_item_id' => 'item1', 'units' => 1]]], $this->sentJson(3));
+    }
+
+    public function test_shipments_are_listed_and_the_delivery_note_is_downloaded(): void
+    {
+        $order = $this->order();
+        $this->respond(200, ['data' => [['id' => 'shp1', 'number' => 'LS-2026-0001']]]);
+        $this->respond(200, ['data' => ['id' => 'shp1', 'number' => 'LS-2026-0001', 'order_id' => 'ord1']]);
+        $this->http->append(new Response(200, ['Content-Type' => 'application/pdf'], '%PDF-1.7 test'));
+
+        $shipments = $order->shipments();
+        $this->assertSame('LS-2026-0001', $shipments->toArray()[0]->number);
+
+        $pdf = $shipments->find('shp1')->deliveryNote();
+
+        $this->assertSame('%PDF-1.7 test', $pdf);
+        $this->assertSame('GET /api/v1/orders/ord1/shipments/shp1/delivery-note Bearer user-token', $this->sentCall(4));
+    }
+
+    public function test_refusals_keep_their_status(): void
+    {
+        $order = $this->order();
+        $this->respond(200, ['data' => []]);
+        $this->respond(409, ['message' => 'Only paid orders can be shipped.', 'error' => 'order_not_paid']);
+
+        try {
+            $order->shipments()->create();
+            $this->fail('expected a ResourceException');
+        } catch (ResourceException $e) {
+            $this->assertSame(409, $e->getCode());
+            $this->assertStringContainsString('Only paid orders can be shipped', $e->getMessage());
+        }
+    }
+}

tests/Id/SubscriptionStatusTest.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\Billable;
+use Anikeen\Id\Enums\SubscriptionStatus;
+use Anikeen\Id\Resources\AppSubscription;
+use Illuminate\Database\Eloquent\Model;
+use PHPUnit\Framework\Attributes\DataProvider;
+
+class SubscriptionStatusTest extends TestCase
+{
+    private const BASE = ['id' => '01JSUB', 'active' => false, 'autorenew' => true, 'cancelled' => false, 'starts_at' => null, 'cancels_at' => null, 'trial_ends_at' => null];
+
+    public static function states(): array
+    {
+        $started = ['starts_at' => '2026-10-01T00:00:00+00:00'];
+
+        return [
+            'draft' => [[], SubscriptionStatus::DRAFT, false],
+            'active' => [['active' => true, ...$started], SubscriptionStatus::ACTIVE, true],
+            'trial' => [['active' => true, 'trial_ends_at' => date(DATE_ATOM, time() + 86400), ...$started], SubscriptionStatus::TRIAL, true],
+            'trial over' => [['active' => true, 'trial_ends_at' => '2026-01-01T00:00:00+00:00', ...$started], SubscriptionStatus::ACTIVE, true],
+            'paused' => [['active' => true, 'autorenew' => false, ...$started], SubscriptionStatus::PAUSED, true],
+            'cancelling' => [['active' => true, 'cancels_at' => '2027-01-01T00:00:00+00:00', ...$started], SubscriptionStatus::CANCELLING, true],
+            'expired' => [['autorenew' => false, ...$started], SubscriptionStatus::EXPIRED, false],
+            'cancelled' => [['autorenew' => false, 'cancelled' => true, ...$started], SubscriptionStatus::CANCELLED, false],
+        ];
+    }
+
+    #[DataProvider('states')]
+    public function test_the_status_follows_the_fields(array $fields, string $status, bool $running): void
+    {
+        $data = [...self::BASE, ...$fields];
+
+        $this->respond(200, ['data' => [$data]]); // subscriptions() loads the list
+        $this->respond(200, ['data' => $data]);
+        $owner = new class extends Model {
+            use Billable;
+        };
+        $owner->anikeen_id_access_token = 'user-token';
+        $subscription = $owner->subscriptions()->find('01JSUB');
+
+        $app = new AppSubscription((object) $data);
+
+        foreach ([$subscription, $app] as $resource) {
+            $this->assertSame($status, $resource->status());
+            $this->assertSame($running, $resource->isActive());
+            $this->assertSame($status === SubscriptionStatus::DRAFT, $resource->isDraft());
+            $this->assertSame($status === SubscriptionStatus::TRIAL, $resource->isTrial());
+            $this->assertSame($status === SubscriptionStatus::PAUSED, $resource->isPaused());
+            $this->assertSame($status === SubscriptionStatus::CANCELLING, $resource->isCancelling());
+            $this->assertSame($status === SubscriptionStatus::EXPIRED, $resource->isExpired());
+            $this->assertSame($status === SubscriptionStatus::CANCELLED, $resource->isCancelled());
+        }
+    }
+}

tests/Id/TokenGuardTest.php

@@ -0,0 +1,204 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\HasAnikeenTokens;
+use Anikeen\Id\Helpers\JwtParser;
+use Anikeen\Id\Http\Middleware\CheckForAnyScope;
+use Anikeen\Id\Http\Middleware\CheckScopes;
+use Firebase\JWT\JWT;
+use Illuminate\Auth\RequestGuard;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Foundation\Auth\User as Authenticatable;
+use Illuminate\Support\Facades\Auth;
+use Illuminate\Support\Facades\Route;
+use Illuminate\Support\Facades\Schema;
+use Illuminate\Support\Str;
+
+class TokenGuardTest extends TestCase
+{
+    private static ?string $privateKey = null;
+
+    private static string $publicKey;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        if (self::$privateKey === null) {
+            $key = openssl_pkey_new(['private_key_bits' => 2048, 'private_key_type' => OPENSSL_KEYTYPE_RSA]);
+            openssl_pkey_export($key, $private);
+            self::$privateKey = $private;
+            self::$publicKey = openssl_pkey_get_details($key)['key'];
+        }
+
+        JwtParser::flushKeys();
+        config([
+            'services.anikeen.public_key' => self::$publicKey,
+            'app.key' => 'base64:'.base64_encode(str_repeat('k', 32)),
+            'database.default' => 'testing',
+            'auth.guards.api' => ['driver' => 'anikeen', 'provider' => 'anikeen'],
+            'auth.providers.anikeen' => ['driver' => 'anikeen', 'model' => GuardUser::class],
+        ]);
+
+        Schema::create('users', function (Blueprint $table) {
+            $table->id();
+            $table->string('anikeen_id')->nullable();
+            $table->string('email');
+        });
+
+        GuardUser::query()->insert([
+            ['id' => 1, 'anikeen_id' => 'ulid-of-alice', 'email' => 'alice@example.com'],
+            ['id' => 2, 'anikeen_id' => '1', 'email' => 'bob@example.com'],
+        ]);
+
+        Route::middleware('auth:api')->get('/me', fn () => ['email' => auth()->user()->email, 'scopes' => auth()->user()->anikeenToken()->scopes]);
+        Route::middleware(['auth:api', CheckScopes::using('user')])->post('/write', fn () => ['ok' => true]);
+        Route::middleware(['auth:api', CheckForAnyScope::using('user', 'user:read')])->get('/read', fn () => ['ok' => true]);
+    }
+
+    /**
+     * Like a fresh request in production: the guard remembers its user per application.
+     */
+    public function call($method, $uri, $parameters = [], $cookies = [], $files = [], $server = [], $content = null)
+    {
+        Auth::forgetGuards();
+
+        return parent::call($method, $uri, $parameters, $cookies, $files, $server, $content);
+    }
+
+    private function token(array $claims = [], ?string $privateKey = null): string
+    {
+        $now = time();
+
+        return JWT::encode(array_merge([
+            'aud' => '019a0000-0000-7000-8000-000000000001',
+            'jti' => Str::random(40),
+            'iat' => $now,
+            'nbf' => $now,
+            'exp' => $now + 3600,
+            'sub' => 'ulid-of-alice',
+            'scopes' => ['user'],
+        ], $claims), $privateKey ?? self::$privateKey, 'RS256');
+    }
+
+    public function test_the_api_guard_resolves(): void
+    {
+        $this->assertInstanceOf(RequestGuard::class, Auth::guard('api'));
+        $this->assertNull(Auth::guard('api')->user());
+    }
+
+    public function test_a_valid_token_resolves_the_user_by_anikeen_id(): void
+    {
+        $this->getJson('/me', ['Authorization' => 'Bearer '.$this->token()])
+            ->assertOk()
+            ->assertExactJson(['email' => 'alice@example.com', 'scopes' => ['user']]);
+    }
+
+    public function test_the_user_is_not_looked_up_by_primary_key(): void
+    {
+        // sub "2" is bob's primary key, but nobody has the Anikeen ID "2"
+        $this->getJson('/me', ['Authorization' => 'Bearer '.$this->token(['sub' => '2'])])->assertUnauthorized();
+        // sub "1" is bob's Anikeen ID (alice's primary key)
+        $this->getJson('/me', ['Authorization' => 'Bearer '.$this->token(['sub' => '1'])])
+            ->assertOk()->assertJsonPath('email', 'bob@example.com');
+    }
+
+    public function test_the_lookup_column_is_configurable(): void
+    {
+        config(['auth.providers.anikeen.column' => 'email']);
+
+        $this->getJson('/me', ['Authorization' => 'Bearer '.$this->token(['sub' => 'bob@example.com'])])
+            ->assertOk()->assertJsonPath('email', 'bob@example.com');
+    }
+
+    public function test_the_eloquent_provider_works_too(): void
+    {
+        config([
+            'auth.guards.api.provider' => 'users',
+            'auth.providers.users' => ['driver' => 'eloquent', 'model' => GuardUser::class],
+        ]);
+
+        $this->getJson('/me', ['Authorization' => 'Bearer '.$this->token()])
+            ->assertOk()->assertJsonPath('email', 'alice@example.com');
+    }
+
+    public function test_invalid_tokens_answer_401_json(): void
+    {
+        $other = openssl_pkey_new(['private_key_bits' => 2048, 'private_key_type' => OPENSSL_KEYTYPE_RSA]);
+        openssl_pkey_export($other, $otherPrivate);
+
+        $cases = [
+            'no token' => [],
+            'garbage' => ['Authorization' => 'Bearer not-a-jwt'],
+            'expired' => ['Authorization' => 'Bearer '.$this->token(['exp' => time() - 120])],
+            'not yet valid' => ['Authorization' => 'Bearer '.$this->token(['nbf' => time() + 600])],
+            'foreign key' => ['Authorization' => 'Bearer '.$this->token([], $otherPrivate)],
+            'unknown user' => ['Authorization' => 'Bearer '.$this->token(['sub' => 'nobody'])],
+            'client credentials' => ['Authorization' => 'Bearer '.$this->token(['sub' => ''])],
+        ];
+
+        foreach ($cases as $case => $headers) {
+            $this->getJson('/me', $headers)->assertUnauthorized()->assertJson(['message' => 'Unauthenticated.'], $case);
+        }
+    }
+
+    public function test_scopes_are_enforced(): void
+    {
+        $read = $this->token(['scopes' => ['user:read']]);
+        $billing = $this->token(['scopes' => ['billing']]);
+        $all = $this->token(['scopes' => ['*']]);
+
+        $this->getJson('/read', ['Authorization' => "Bearer $read"])->assertOk();
+        $this->postJson('/write', [], ['Authorization' => "Bearer $read"])->assertForbidden();
+        $this->getJson('/read', ['Authorization' => "Bearer $billing"])->assertForbidden();
+        $this->postJson('/write', [], ['Authorization' => "Bearer $all"])->assertOk();
+        $this->postJson('/write', [], ['Authorization' => 'Bearer '.$this->token()])->assertOk();
+    }
+
+    public function test_token_can(): void
+    {
+        $user = GuardUser::query()->find(1)->withAnikeenAccessToken((object) ['scopes' => ['user:read']]);
+
+        $this->assertTrue($user->anikeenTokenCan('user:read'));
+        $this->assertFalse($user->anikeenTokenCan('user'));
+        $this->assertTrue($user->anikeenTokenCanAny(['user', 'user:read']));
+        $this->assertFalse((new GuardUser())->anikeenTokenCan('user'));
+    }
+
+    public function test_revoked_tokens_are_rejected_when_revocation_is_verified(): void
+    {
+        config(['services.anikeen.verify_revocation' => true]);
+        $active = $this->token();
+        $revoked = $this->token();
+
+        $this->respond(200, ['data' => ['id' => 'ulid-of-alice']]);
+        $this->getJson('/me', ['Authorization' => "Bearer $active"])->assertOk();
+        // cached: no second request to Anikeen ID
+        $this->getJson('/me', ['Authorization' => "Bearer $active"])->assertOk();
+        $this->assertCount(1, $this->sent);
+        $this->assertSame("Bearer $active", $this->sent[0]['request']->getHeaderLine('Authorization'));
+        $this->assertStringEndsWith('v1/user', (string) $this->sent[0]['request']->getUri());
+
+        $this->respond(401, ['message' => 'Unauthenticated.']);
+        $this->getJson('/me', ['Authorization' => "Bearer $revoked"])->assertUnauthorized();
+
+        // Anikeen ID down: fail closed, not cached
+        $other = $this->token();
+        $this->respond(503);
+        $this->getJson('/me', ['Authorization' => "Bearer $other"])->assertUnauthorized();
+        $this->respond(200, ['data' => ['id' => 'ulid-of-alice']]);
+        $this->getJson('/me', ['Authorization' => "Bearer $other"])->assertOk();
+    }
+}
+
+class GuardUser extends Authenticatable
+{
+    use HasAnikeenTokens;
+
+    protected $table = 'users';
+
+    public $timestamps = false;
+
+    protected $guarded = [];
+}

tests/Id/UserApiExceptionsTest.php

@@ -0,0 +1,97 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\Billable;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Exceptions\CollectionException;
+use Anikeen\Id\Exceptions\ConfirmationRequiredException;
+use Anikeen\Id\Exceptions\ResourceException;
+use GuzzleHttp\Exception\ConnectException;
+use GuzzleHttp\Psr7\Request;
+use Illuminate\Database\Eloquent\Model;
+
+class UserApiExceptionsTest extends TestCase
+{
+    private function user(): Model
+    {
+        $user = new class extends Model {
+            use Billable;
+        };
+        $user->anikeen_id_access_token = 'user-token';
+
+        return $user;
+    }
+
+    public function test_a_refused_request_carries_status_and_error_code(): void
+    {
+        $this->respond(200, ['data' => []]); // orders() loads the list
+        $this->respond(422, ['message' => 'The billing address is missing.', 'error' => 'billing_address_missing']);
+
+        try {
+            $this->user()->orders()->create(['items' => []]);
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertInstanceOf(ResourceException::class, $e, 'existing catch (ResourceException) blocks keep working');
+            $this->assertSame(422, $e->status);
+            $this->assertSame(422, $e->getCode());
+            $this->assertSame('billing_address_missing', $e->error);
+            $this->assertSame('The billing address is missing', $e->getMessage());
+            $this->assertFalse($e->isTemporary());
+        }
+    }
+
+    public function test_an_unknown_id_is_not_found(): void
+    {
+        $this->respond(200, ['data' => []]);
+        $this->respond(404, ['message' => 'Not found.']);
+
+        try {
+            $this->user()->orders()->find('01JMISSING');
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertTrue($e->isNotFound());
+            $this->assertNull($e->error);
+        }
+    }
+
+    public function test_a_failed_list_is_an_api_exception_too(): void
+    {
+        $this->respond(503, ['message' => 'Maintenance.']);
+
+        try {
+            $this->user()->invoices();
+            $this->fail('Expected a CollectionException.');
+        } catch (CollectionException $e) {
+            $this->assertInstanceOf(ApiException::class, $e);
+            $this->assertSame(503, $e->status);
+            $this->assertTrue($e->isTemporary());
+        }
+    }
+
+    public function test_no_response_is_temporary_with_status_zero(): void
+    {
+        $this->respond(200, ['data' => []]);
+        $this->http->append(new ConnectException('Connection refused', new Request('GET', 'v1/orders/01J')));
+
+        try {
+            $this->user()->orders()->find('01J');
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertSame(0, $e->status);
+            $this->assertTrue($e->isTemporary());
+            $this->assertInstanceOf(ConnectException::class, $e->getPrevious());
+        }
+    }
+
+    public function test_confirmation_required_stays_its_own_exception(): void
+    {
+        $this->respond(200, ['data' => []]);
+        $this->respond(200, ['data' => ['id' => '01JORDER', 'status' => 'draft']]);
+        $this->respond(403, ['message' => 'Confirm it on Anikeen ID.', 'error' => 'confirmation_required', 'confirmation_url' => 'https://id.test/confirm/01JORDER']);
+
+        $this->expectException(ConfirmationRequiredException::class);
+
+        $this->user()->orders()->find('01JORDER')->checkout();
+    }
+}

tests/Id/WebhookTest.php

@@ -0,0 +1,98 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\Exceptions\SignatureVerificationException;
+use Anikeen\Id\Webhooks\EventType;
+use Anikeen\Id\Webhooks\Webhook;
+
+class WebhookTest extends TestCase
+{
+    private string $secret = 'whsec_test';
+
+    private string $payload = '{"id":"01JEVT","type":"order.completed","created":1790000000,"data":{"object":{"id":"01JORD"}}}';
+
+    private function header(?int $timestamp = null, ?string $secret = null): string
+    {
+        $timestamp ??= time();
+
+        return "t={$timestamp},v1=" . hash_hmac('sha256', "{$timestamp}.{$this->payload}", $secret ?? $this->secret);
+    }
+
+    public function test_a_signed_event_is_returned(): void
+    {
+        $event = Webhook::constructEvent($this->payload, $this->header(), $this->secret);
+
+        $this->assertSame('order.completed', $event['type']);
+        $this->assertSame('01JORD', $event['data']['object']['id']);
+    }
+
+    public function test_a_wrong_secret_is_rejected(): void
+    {
+        $this->expectException(SignatureVerificationException::class);
+
+        Webhook::constructEvent($this->payload, $this->header(secret: 'whsec_other'), $this->secret);
+    }
+
+    public function test_a_changed_body_is_rejected(): void
+    {
+        $this->expectException(SignatureVerificationException::class);
+
+        Webhook::constructEvent(str_replace('01JORD', '01JXXX', $this->payload), $this->header(), $this->secret);
+    }
+
+    public function test_old_requests_are_rejected(): void
+    {
+        $this->expectException(SignatureVerificationException::class);
+
+        Webhook::constructEvent($this->payload, $this->header(time() - 600), $this->secret);
+    }
+
+    public function test_a_missing_header_is_rejected(): void
+    {
+        $this->expectException(SignatureVerificationException::class);
+
+        Webhook::constructEvent($this->payload, null, $this->secret);
+    }
+
+    public function test_a_renewal_carries_the_booked_period(): void
+    {
+        $this->payload = json_encode(['id' => '01JEVT', 'type' => EventType::SUBSCRIPTION_RENEWED, 'created' => time(), 'data' => [
+            'object' => ['id' => '01JSUB', 'status' => 'active'],
+            'period' => ['object' => 'subscription_period', 'subscription_id' => '01JSUB', 'period_start' => '2026-11-01T00:00:00+00:00', 'period_end' => '2026-12-01T00:00:00+00:00', 'periods' => 1, 'first_period' => true, 'unit' => 'month', 'order_id' => '01JORD', 'order_item_id' => '01JITEM', 'items' => [], 'currency_iso' => 'EUR', 'net_amount' => 8],
+        ]]);
+
+        $event = Webhook::constructEvent($this->payload, $this->header(), $this->secret);
+
+        $this->assertSame('subscription.renewed', $event['type']);
+        $this->assertSame('01JORD', $event['data']['period']['order_id']);
+        $this->assertTrue($event['data']['period']['first_period']);
+        $this->assertContains(EventType::SUBSCRIPTION_RENEWED, EventType::all());
+    }
+
+    public function test_refunds_have_their_own_event_type(): void
+    {
+        $this->assertSame('order.refunded', EventType::ORDER_REFUNDED);
+        $this->assertContains(EventType::ORDER_REFUNDED, EventType::all());
+    }
+
+    public function test_billing_limit_events_have_their_own_types(): void
+    {
+        $this->assertSame('billing_limit.reached', EventType::BILLING_LIMIT_REACHED);
+        $this->assertSame('billing_limit.available', EventType::BILLING_LIMIT_AVAILABLE);
+        $this->assertContains(EventType::BILLING_LIMIT_REACHED, EventType::all());
+        $this->assertContains(EventType::BILLING_LIMIT_AVAILABLE, EventType::all());
+    }
+
+    public function test_a_change_carries_the_previous_attributes(): void
+    {
+        $this->payload = json_encode(['id' => '01JEVT', 'type' => EventType::SUBSCRIPTION_UPDATED, 'created' => time(), 'data' => [
+            'object' => ['id' => '01JSUB', 'price' => 14.99],
+            'previous_attributes' => ['price' => 9.99],
+        ]]);
+
+        $event = Webhook::constructEvent($this->payload, $this->header(), $this->secret);
+
+        $this->assertSame(9.99, $event['data']['previous_attributes']['price']);
+    }
+}