App subscriptions: manage a user's subscriptions with the app's own token

- $user->appSubscriptions(): create (idempotency_key), find, all, checkout, revoke, pause,
  resume, update against /v1/client/subscriptions with a client credentials token, so apps don't
  depend on the user's login
- user id from the billable's anikeen_id (AnikeenId::useUserIdField())
- ApiException with status, stable error code, isNotFound/isConflict/isTemporary; network
  errors no longer escape as raw Guzzle exceptions
- rejected app tokens are renewed once; asApp() never changes the shared client's token
- tests (testbench + Guzzle mock) and CI

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/tests.yml

@@ -0,0 +1,22 @@
+name: tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        php: ['8.3', '8.4']
+    steps:
+      - uses: actions/checkout@v6
+      - uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          coverage: none
+      - run: composer update --no-interaction --prefer-dist --no-progress
+      - run: vendor/bin/phpunit

README.md

@@ -93,6 +93,55 @@ class User extends Authenticatable
 
 then, you can use the `Billable` trait methods in your user model.
 
+### App subscriptions (trusted apps, no user token)
+
+`subscriptions()` acts with the user's own access token and stops working when the user's login
+expired. Trusted apps can manage a user's subscriptions with the app's own token (client
+credentials, scope `subscriptions:client`) instead:
+
+```php
+$subscriptions = $team->owner->appSubscriptions(); // nothing is requested yet
+
+$subscription = $subscriptions->create([
+    'group' => $team->id,
+    'name' => 'Cloud Server S',
+    'unit' => 'hour',
+    'price' => 0.0137,
+    'idempotency_key' => "server:{$pendingServer->id}", // retries return the same subscription
+]);
+
+$subscription->checkout();             // bill the first period
+$subscription->pause();                // expires when the paid period ends
+$subscription->resume();               // expired subscriptions start a new period
+$subscription->revoke(refund: false);  // cancel
+
+$subscriptions->find($id);             // null if unknown or not this user's
+$subscriptions->all(['group' => $team->id, 'active' => true]);
+```
+
+The user's Anikeen ID is read from the billable's `anikeen_id` attribute
+(`AnikeenId::useUserIdField('…')` to change it). The app must be trusted by Anikeen ID; it sees the
+subscriptions it created (plus those of clients delegated to it).
+
+Failures throw `Anikeen\Id\Exceptions\ApiException` with `status` (0 = not reachable), a stable
+`error` code (`already_active`, `already_cancelled`, `not_active`, `already_paused`,
+`already_resumed`, `billing_address_missing`, `not_changeable`, `subscription_not_found`,
+`idempotency_key_conflict`) and `isNotFound()`, `isConflict()`, `isTemporary()`:
+
+```php
+try {
+    $subscription->revoke();
+} catch (ApiException $e) {
+    if ($e->isNotFound() || $e->error === 'already_cancelled') {
+        // already gone
+    } elseif ($e->isTemporary()) {
+        // retry later
+    } else {
+        throw $e;
+    }
+}
+```
+
 ### Change the default access token / refresh token field name
 
 If you access / refresh token fields differs from the default `anikeen_id_access_token` / `anikeen_id_refresh_token`, you can specify the field name in the `AppServiceProvider` boot method:

composer.json

@@ -22,8 +22,9 @@
     "firebase/php-jwt": "^7.0"
   },
   "require-dev": {
-    "phpunit/phpunit": "^8.0|^9.0",
-    "laravel/framework": "^10.0|^11.0|^12.0|^13.0"
+    "phpunit/phpunit": "^11.0|^12.0",
+    "laravel/framework": "^10.0|^11.0|^12.0|^13.0",
+    "orchestra/testbench": "^9.0|^10.0|^11.0"
   },
   "autoload": {
     "psr-4": {

phpunit.xml

@@ -1,29 +1,16 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit bootstrap="vendor/autoload.php"
-         backupGlobals="false"
-         backupStaticAttributes="false"
-         colors="true"
-         verbose="true"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
-         processIsolation="false"
-         stopOnFailure="false"
-         printerClass="\Codedungeon\PHPUnitPrettyResultPrinter\Printer">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         colors="true">
     <testsuites>
         <testsuite name="Unit">
             <directory>tests</directory>
         </testsuite>
     </testsuites>
-    <filter>
-        <whitelist processUncoveredFilesFromWhitelist="true">
+    <source>
+        <include>
             <directory suffix=".php">src</directory>
-        </whitelist>
-    </filter>
-    <php>
-        <env name="ANIKEEN_ID_KEY" value="38"/>
-        <env name="ANIKEEN_ID_SECRET" value="2goNRF8x37HPVZVaa28ySZGVXJuksvxnxM7TcGzM"/>
-        <env name="ANIKEEN_ID_BASE_URL" value="https://id.anikeen.com"/>
-        <env name="CLIENT_ACCESS_TOKEN" value="eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJhdWQiOiIxNSIsImp0aSI6IjAxN2QxZDg0Y2MxNjAyZTYxOGZkNjYwZGViZWVjMDY4MTk2YmYzMDk1OGMzY2RiYzBjZmJkZWFjZjFhOTUxODQzZDU1YTk3OGY2YWIxY2YzIiwiaWF0IjoxNjY0NjIzMzA4LjQyODI4MSwibmJmIjoxNjY0NjIzMzA4LjQyODI4NCwiZXhwIjoxNjgwMzQ4MTA4LjQxNjc4MSwic3ViIjoiMzkiLCJzY29wZXMiOlsiYXBpIiwicmVhZF91c2VyIl0sImNsaWVudCI6eyJ0cnVzdGVkIjpmYWxzZX19.vxnzCaU4PpOrNVHa5AnGSS6gX_RCvxIERAnHFhjTrUzRafV9mr2Cvwd-BDVYoUr10wHvxa_TJSYfnAdDuhE-MEyDv13O3dL2XGTtJNa_Rg6L6CQ0JvC3wL-lWPvGPFax9pu-_lqbA3jm5B08hc3-7tq3f2nXcxjhtkqT6TTJv1-RCAppb2HCXiUDAqANzbhyInDjOH2WvFj1OGC_AI03J3W2KRWyeFLtUne8XKPFyr9XGcPuTrqogcuuXLeUt2kcf2bXbuIV1OlgIECrDiP1Ee0F2AzPs27ZVJ2z0R0JbT6AubKhGl5_Qi27cwjOH7hT2dmjcF1mLjzpN1uChLIdSnGSoStH8VzYHnHE2I8G-owW_aadG2UmGdnRY143q6g_28f3WIZNSucBSXkwFeS_t4fylsvpxhpjYJusf5qiEU_X3YbeawYMUCFUkSD2XTIypAqMJLNZQAeJ52eyL-9fln-Bv7n9v7K9G6ieR6Tm0tsJ1PRnaQi7rA1NTFwHoQmIOW9tfMycLzT7bgSoz3ra6Ez2J7ZNuWBZNKS0O-0YfSrAWyWK5U8YRfQuSVzP2VrIU63K6RGU2c284PfQGy11kgKUNQPykirb8p7MDQ8PwrxKaylBnD6hhDgjqEh2bfsr_43DfJA0R58L1HK3BmQnxgap0C77wK1e0yNlABpN28Q"/>
-    </php>
+        </include>
+    </source>
 </phpunit>

src/Id/AnikeenId.php

@@ -58,6 +58,8 @@ class AnikeenId
      */
     private static string $refreshTokenField = 'anikeen_id_refresh_token';
 
+    private static string $userIdField = 'anikeen_id';
+
     /**
      * Guzzle is used to make http requests.
      */
@@ -143,6 +145,41 @@ class AnikeenId
         return self::$accessTokenField;
     }
 
+    /**
+     * Attribute of the billable model that holds the user's Anikeen ID (used by app requests,
+     * e.g. appSubscriptions(), which act on behalf of a user without the user's token).
+     */
+    public static function useUserIdField(string $userIdField): void
+    {
+        self::$userIdField = $userIdField;
+    }
+
+    public static function getUserIdField(): string
+    {
+        return self::$userIdField;
+    }
+
+    /**
+     * A copy that uses the app's own access token (client credentials) instead of a user's token.
+     * The shared instance keeps its token, so app rights never leak into other requests.
+     *
+     * @throws Exceptions\RequestFreshAccessTokenException
+     */
+    public function asApp(): static
+    {
+        return (clone $this)->withToken(app(Contracts\AppTokenRepository::class)->getAccessToken());
+    }
+
+    /**
+     * Replace the HTTP client, e.g. with one using a Guzzle MockHandler in tests.
+     */
+    public function setHttpClient(Client $client): static
+    {
+        $this->client = $client;
+
+        return $this;
+    }
+
     public static function getMode(): string
     {
         return config('services.anikeen.mode') ?: 'production';

src/Id/Concerns/ManagesSubscriptions.php

@@ -2,6 +2,7 @@
 
 namespace Anikeen\Id\Concerns;
 
+use Anikeen\Id\Resources\AppSubscriptions;
 use Anikeen\Id\Resources\Subscriptions;
 use Throwable;
 
@@ -24,4 +25,14 @@ trait ManagesSubscriptions
 
         return $this->subscriptionsCache;
     }
+
+    /**
+     * The user's subscriptions, managed with the app's own token instead of the user's
+     * (trusted apps only, scope subscriptions:client). Use this in jobs and anywhere the user's
+     * login may have expired.
+     */
+    public function appSubscriptions(): AppSubscriptions
+    {
+        return new AppSubscriptions($this);
+    }
 }

src/Id/Exceptions/ApiException.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Anikeen\Id\Exceptions;
+
+use Throwable;
+
+/**
+ * A request to the ID service failed. `status` is the HTTP status (0 when the service could not
+ * be reached), `error` the service's stable error code when it sent one (e.g. "already_cancelled").
+ */
+class ApiException extends ResourceException
+{
+    public function __construct(
+        string $message,
+        public readonly int $status = 0,
+        public readonly ?string $error = null,
+        ?Throwable $previous = null,
+    ) {
+        parent::__construct($message, $status, $previous);
+    }
+
+    public function isNotFound(): bool
+    {
+        return $this->status === 404;
+    }
+
+    public function isConflict(): bool
+    {
+        return $this->status === 409;
+    }
+
+    /**
+     * The ID service could not be reached (network error, timeout) or failed (5xx): retry later.
+     */
+    public function isTemporary(): bool
+    {
+        return $this->status === 0 || $this->status >= 500 || $this->status === 429;
+    }
+}

src/Id/Repository/AppTokenRepository.php

@@ -32,6 +32,14 @@ class AppTokenRepository implements Repository
         return $this->requestFreshAccessToken('*');
     }
 
+    /**
+     * Drop the cached token, e.g. after the ID service rejected it.
+     */
+    public function forgetAccessToken(): void
+    {
+        Cache::forget(self::ACCESS_TOKEN_CACHE_KEY);
+    }
+
     /**
      * @throws RequestFreshAccessTokenException
      */

src/Id/Resources/AppSubscription.php

@@ -0,0 +1,126 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Support\AppRequest;
+use JsonSerializable;
+
+/**
+ * A subscription managed by the app itself (client credentials), see AppSubscriptions.
+ *
+ * @property string $id
+ * @property string $user_id
+ * @property ?string $group
+ * @property string $name
+ * @property ?string $description
+ * @property string $unit
+ * @property float $price
+ * @property ?float $vat_rate
+ * @property bool $active
+ * @property bool $autorenew
+ * @property bool $cancelled
+ * @property ?string $status "active" or "inactive"
+ * @property ?string $starts_at
+ * @property ?string $ends_at
+ * @property ?string $accounting_at
+ * @property bool $is_past_due
+ * @property int $failed_renewal_retries
+ * @property ?array $payload
+ * @property ?string $idempotency_key
+ */
+class AppSubscription 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});
+    }
+
+    /**
+     * Change a subscription that wasn't checked out yet.
+     *
+     * @throws ApiException
+     */
+    public function update(array $attributes): self
+    {
+        return $this->send('PUT', '', $attributes);
+    }
+
+    /**
+     * Activate the subscription and bill its first period.
+     *
+     * @throws ApiException 409 "already_active", "billing_address_missing", …
+     */
+    public function checkout(): self
+    {
+        return $this->send('PUT', '/checkout');
+    }
+
+    /**
+     * Cancel the subscription. With $refund (only within 14 days of its start), its not yet
+     * charged usage is credited.
+     *
+     * @throws ApiException 409 "already_cancelled", 404 "subscription_not_found", …
+     */
+    public function revoke(bool $refund = false): self
+    {
+        return $this->send('PUT', '/revoke', ['refund' => $refund]);
+    }
+
+    /**
+     * Stop renewing; the subscription expires when its paid period ends.
+     *
+     * @throws ApiException
+     */
+    public function pause(): self
+    {
+        return $this->send('PUT', '/pause');
+    }
+
+    /**
+     * Renew again (an expired subscription starts a new period).
+     *
+     * @throws ApiException
+     */
+    public function resume(): self
+    {
+        return $this->send('PUT', '/resume');
+    }
+
+    /**
+     * @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, ?array $payload = null): self
+    {
+        $this->data = AppRequest::send($method, sprintf('v1/client/subscriptions/%s%s', $this->id, $action), $payload)->data;
+
+        return $this;
+    }
+}

src/Id/Resources/AppSubscriptions.php

@@ -0,0 +1,116 @@
+<?php
+
+namespace Anikeen\Id\Resources;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Contracts\Billable;
+use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Support\AppRequest;
+use Illuminate\Database\Eloquent\Model;
+use InvalidArgumentException;
+
+/**
+ * Subscriptions of a user, managed with the app's own token (client credentials, scope
+ * `subscriptions:client`) instead of the user's token, so they keep working when the user's
+ * login expired. The app has to be trusted by the ID service. Nothing is requested until a
+ * method is called.
+ */
+class AppSubscriptions
+{
+    public function __construct(protected Billable|Model $billable)
+    {
+    }
+
+    /**
+     * The user's Anikeen ID (see AnikeenId::useUserIdField()).
+     */
+    public function userId(): string
+    {
+        $userId = $this->billable->{AnikeenId::getUserIdField()} ?? null;
+
+        if (empty($userId)) {
+            throw new InvalidArgumentException(sprintf('The billable has no Anikeen ID in [%s].', AnikeenId::getUserIdField()));
+        }
+
+        return (string) $userId;
+    }
+
+    /**
+     * Create a subscription for the user (it is billed only after checkout()).
+     *
+     * @param array{
+     *     group?: null|string,
+     *     name: string,
+     *     description?: null|string,
+     *     unit: string,
+     *     price: float|string,
+     *     vat_rate?: float,
+     *     payload?: null|array,
+     *     ends_at?: null|string,
+     *     webhook_url?: null|string,
+     *     webhook_secret?: null|string,
+     *     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.
+     *
+     * @throws ApiException
+     */
+    public function create(array $attributes): AppSubscription
+    {
+        return new AppSubscription(AppRequest::send('POST', 'v1/client/subscriptions', [
+            ...$attributes,
+            'user_id' => $this->userId(),
+        ])->data);
+    }
+
+    /**
+     * Find one of the user's subscriptions; null when it doesn't exist (or belongs to someone else).
+     *
+     * @throws ApiException
+     */
+    public function find(string $id): ?AppSubscription
+    {
+        try {
+            $subscription = new AppSubscription(AppRequest::send('GET', sprintf('v1/client/subscriptions/%s', $id))->data);
+        } catch (ApiException $e) {
+            if ($e->isNotFound()) {
+                return null;
+            }
+
+            throw $e;
+        }
+
+        return $subscription->user_id === $this->userId() ? $subscription : null;
+    }
+
+    /**
+     * All of the user's subscriptions, optionally filtered.
+     *
+     * @param array{group?: string, active?: bool, cancelled?: bool} $filters
+     * @return list<AppSubscription>
+     *
+     * @throws ApiException
+     */
+    public function all(array $filters = []): array
+    {
+        $subscriptions = [];
+        $page = 1;
+
+        do {
+            $result = AppRequest::send('GET', 'v1/client/subscriptions', null, [
+                ...array_map(fn ($value) => is_bool($value) ? (int) $value : $value, $filters),
+                'user_id' => $this->userId(),
+                'per_page' => 100,
+                'page' => $page,
+            ]);
+
+            foreach ($result->data as $data) {
+                $subscriptions[] = new AppSubscription($data);
+            }
+
+            $lastPage = (int) ($result->meta->last_page ?? $page);
+        } while ($page++ < $lastPage);
+
+        return $subscriptions;
+    }
+}

src/Id/Support/AppRequest.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace Anikeen\Id\Support;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Contracts\AppTokenRepository;
+use Anikeen\Id\Exceptions\ApiException;
+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.
+ */
+final class AppRequest
+{
+    /**
+     * @throws ApiException
+     */
+    public static function send(string $method, string $path, ?array $payload = null, array $query = []): Result
+    {
+        $result = self::attempt($method, $path, $payload, $query);
+
+        if ($result->status === 401) {
+            $tokens = app(AppTokenRepository::class);
+
+            if (method_exists($tokens, 'forgetAccessToken')) {
+                $tokens->forgetAccessToken();
+                $result = self::attempt($method, $path, $payload, $query);
+            }
+        }
+
+        if (!$result->success()) {
+            $body = is_object($result->data) ? $result->data : null;
+
+            throw new ApiException(
+                sprintf('Anikeen ID request %s %s failed: %s', $method, $path, $body->message ?? $result->error()),
+                $result->response()?->getStatusCode() ?? 0,
+                $body->error ?? null,
+                $result->exception,
+            );
+        }
+
+        return $result;
+    }
+
+    /**
+     * @throws ApiException
+     */
+    private static function attempt(string $method, string $path, ?array $payload, array $query): Result
+    {
+        try {
+            return app(AnikeenId::class)->asApp()->request($method, $path, $payload, $query);
+        } catch (ApiException $e) {
+            throw $e;
+        } catch (GuzzleException|Throwable $e) {
+            // network errors / timeouts (ConnectException isn't a RequestException) and token errors
+            throw new ApiException(sprintf('Anikeen ID is not reachable: %s', $e->getMessage()), 0, null, $e);
+        }
+    }
+}

tests/Id/AppSubscriptionsTest.php

@@ -0,0 +1,172 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Billable;
+use Anikeen\Id\Exceptions\ApiException;
+use GuzzleHttp\Exception\ConnectException;
+use GuzzleHttp\Psr7\Request;
+use Illuminate\Database\Eloquent\Model;
+use InvalidArgumentException;
+
+class AppSubscriptionsTest extends TestCase
+{
+    private function owner(?string $anikeenId = '01JUSER'): Model
+    {
+        $owner = new class extends Model {
+            use Billable;
+
+            protected $guarded = [];
+        };
+        $owner->anikeen_id = $anikeenId;
+        $owner->anikeen_id_access_token = 'user-token';
+
+        return $owner;
+    }
+
+    private function subscription(array $overrides = []): array
+    {
+        return ['data' => ['id' => '01JSUB', 'user_id' => '01JUSER', 'name' => 'Server', 'active' => false, 'cancelled' => false, ...$overrides]];
+    }
+
+    public function test_create_sends_the_user_id_with_the_app_token(): void
+    {
+        $this->respond(201, $this->subscription());
+
+        $subscription = $this->owner()->appSubscriptions()->create(['group' => 'team-1', 'name' => 'Server', 'unit' => 'hour', 'price' => '0.0137', 'idempotency_key' => 'server:1']);
+
+        $request = $this->sent[0]['request'];
+        $this->assertSame('POST', $request->getMethod());
+        $this->assertSame('/api/v1/client/subscriptions', $request->getUri()->getPath());
+        $this->assertSame('Bearer app-token', $request->getHeaderLine('Authorization'));
+        $this->assertSame(['group' => 'team-1', 'name' => 'Server', 'unit' => 'hour', 'price' => '0.0137', 'idempotency_key' => 'server:1', 'user_id' => '01JUSER'], $this->sentJson(0));
+        $this->assertSame('01JSUB', $subscription->id);
+    }
+
+    public function test_nothing_is_requested_until_a_method_is_called(): void
+    {
+        $this->owner()->appSubscriptions();
+
+        $this->assertCount(0, $this->sent);
+    }
+
+    public function test_actions_use_the_app_endpoints(): void
+    {
+        $this->respond(201, $this->subscription());
+        $this->respond(200, $this->subscription(['active' => true]));
+        $this->respond(200, $this->subscription(['active' => true, 'autorenew' => false]));
+        $this->respond(200, $this->subscription(['active' => true, 'autorenew' => true]));
+        $this->respond(200, $this->subscription(['cancelled' => true]));
+
+        $subscription = $this->owner()->appSubscriptions()->create(['name' => 'Server', 'unit' => 'hour', 'price' => 1]);
+
+        $this->assertTrue($subscription->checkout()->active);
+        $this->assertFalse($subscription->pause()->autorenew);
+        $this->assertTrue($subscription->resume()->autorenew);
+        $this->assertTrue($subscription->revoke(refund: true)->cancelled);
+
+        $this->assertSame([
+            'POST /api/v1/client/subscriptions',
+            'PUT /api/v1/client/subscriptions/01JSUB/checkout',
+            'PUT /api/v1/client/subscriptions/01JSUB/pause',
+            'PUT /api/v1/client/subscriptions/01JSUB/resume',
+            'PUT /api/v1/client/subscriptions/01JSUB/revoke',
+        ], array_map(fn ($entry) => $entry['request']->getMethod() . ' ' . $entry['request']->getUri()->getPath(), $this->sent));
+        $this->assertSame(['refund' => true], $this->sentJson(4));
+    }
+
+    public function test_errors_carry_status_and_error_code(): void
+    {
+        $this->respond(409, ['message' => 'Product subscription has already been cancelled.', 'error' => 'already_cancelled']);
+
+        try {
+            $this->owner()->appSubscriptions()->create(['name' => 'Server', 'unit' => 'hour', 'price' => 1]);
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertSame(409, $e->status);
+            $this->assertSame('already_cancelled', $e->error);
+            $this->assertTrue($e->isConflict());
+            $this->assertFalse($e->isTemporary());
+        }
+    }
+
+    public function test_find_returns_null_for_unknown_subscriptions_and_other_users(): void
+    {
+        $this->respond(404, ['message' => 'Subscription not found.', 'error' => 'subscription_not_found']);
+        $this->respond(200, $this->subscription(['user_id' => '01JSOMEONEELSE']));
+        $this->respond(200, $this->subscription());
+
+        $subscriptions = $this->owner()->appSubscriptions();
+
+        $this->assertNull($subscriptions->find('01JUNKNOWN'));
+        $this->assertNull($subscriptions->find('01JSUB'));
+        $this->assertSame('01JSUB', $subscriptions->find('01JSUB')->id);
+    }
+
+    public function test_all_follows_pages_and_filters_by_user(): void
+    {
+        $this->respond(200, ['data' => [['id' => 'a', 'user_id' => '01JUSER']], 'meta' => ['current_page' => 1, 'last_page' => 2, 'total' => 2], 'links' => ['next' => null]]);
+        $this->respond(200, ['data' => [['id' => 'b', 'user_id' => '01JUSER']], 'meta' => ['current_page' => 2, 'last_page' => 2, 'total' => 2], 'links' => ['next' => null]]);
+
+        $all = $this->owner()->appSubscriptions()->all(['group' => 'team-1', 'active' => true]);
+
+        $this->assertSame(['a', 'b'], array_map(fn ($s) => $s->id, $all));
+        parse_str($this->sent[0]['request']->getUri()->getQuery(), $query);
+        $this->assertSame(['group' => 'team-1', 'active' => '1', 'user_id' => '01JUSER', 'per_page' => '100', 'page' => '1'], $query);
+    }
+
+    public function test_a_rejected_app_token_is_renewed_once(): void
+    {
+        $this->respond(401, ['message' => 'Unauthenticated.']);
+        $this->respond(200, ['data' => [], 'meta' => ['last_page' => 1], 'links' => ['next' => null]]);
+
+        $this->assertSame([], $this->owner()->appSubscriptions()->all());
+
+        $this->assertSame('Bearer app-token', $this->sent[0]['request']->getHeaderLine('Authorization'));
+        $this->assertSame('Bearer fresh-app-token', $this->sent[1]['request']->getHeaderLine('Authorization'));
+    }
+
+    public function test_an_unreachable_service_is_a_temporary_api_exception(): void
+    {
+        $this->http->append(new ConnectException('Connection refused', new Request('GET', 'v1/client/subscriptions')));
+
+        try {
+            $this->owner()->appSubscriptions()->all();
+            $this->fail('Expected an ApiException.');
+        } catch (ApiException $e) {
+            $this->assertSame(0, $e->status);
+            $this->assertTrue($e->isTemporary());
+        }
+    }
+
+    public function test_the_shared_client_keeps_the_users_token(): void
+    {
+        $this->respond(200, ['data' => [], 'meta' => ['last_page' => 1], 'links' => ['next' => null]]);
+        app(AnikeenId::class)->withToken('user-token');
+
+        $this->owner()->appSubscriptions()->all();
+
+        $this->assertSame('user-token', app(AnikeenId::class)->getToken());
+    }
+
+    public function test_the_user_id_field_is_configurable(): void
+    {
+        AnikeenId::useUserIdField('id_service_user');
+        $owner = $this->owner(null);
+        $owner->id_service_user = '01JOTHER';
+
+        try {
+            $this->assertSame('01JOTHER', $owner->appSubscriptions()->userId());
+        } finally {
+            AnikeenId::useUserIdField('anikeen_id');
+        }
+    }
+
+    public function test_a_missing_user_id_is_reported(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        $this->owner(null)->appSubscriptions()->create(['name' => 'Server', 'unit' => 'hour', 'price' => 1]);
+    }
+}

tests/Id/TestCase.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace Anikeen\Id\Tests;
+
+use Anikeen\Id\AnikeenId;
+use Anikeen\Id\Contracts\AppTokenRepository;
+use Anikeen\Id\Providers\AnikeenIdServiceProvider;
+use GuzzleHttp\Client;
+use GuzzleHttp\Handler\MockHandler;
+use GuzzleHttp\HandlerStack;
+use GuzzleHttp\Middleware;
+use GuzzleHttp\Psr7\Response;
+use Orchestra\Testbench\TestCase as Orchestra;
+
+abstract class TestCase extends Orchestra
+{
+    protected MockHandler $http;
+
+    /** @var list<array{request: \Psr\Http\Message\RequestInterface}> */
+    protected array $sent = [];
+
+    protected function getPackageProviders($app): array
+    {
+        return [AnikeenIdServiceProvider::class];
+    }
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        config(['services.anikeen.client_id' => 'app-client', 'services.anikeen.client_secret' => 'secret']);
+
+        $this->http = new MockHandler();
+        $stack = HandlerStack::create($this->http);
+        $stack->push(Middleware::history($this->sent));
+
+        $this->app->instance(AnikeenId::class, (new AnikeenId())->setHttpClient(new Client(['handler' => $stack, 'base_uri' => 'https://id.test/api/'])));
+        $this->app->instance(AppTokenRepository::class, new class implements AppTokenRepository {
+            public int $forgotten = 0;
+
+            public function getAccessToken(): string
+            {
+                return $this->forgotten ? 'fresh-app-token' : 'app-token';
+            }
+
+            public function forgetAccessToken(): void
+            {
+                $this->forgotten++;
+            }
+        });
+    }
+
+    protected function respond(int $status, array $body = []): void
+    {
+        $this->http->append(new Response($status, ['Content-Type' => 'application/json'], json_encode($body)));
+    }
+
+    protected function sentJson(int $index): array
+    {
+        return json_decode((string) $this->sent[$index]['request']->getBody(), true) ?? [];
+    }
+}