Api Hardening Patterns

API Hardening Patterns

When to use

Use this skill when building or reviewing Laravel APIs that need stronger security, safer defaults, and better abuse resistance. It is most useful for public APIs, partner integrations, mobile backends, webhook endpoints, or any route group under routes/api.php.

Input parameters

• API routes, controllers, request classes, and policies to inspect.
• Authentication model such as Sanctum, Passport, or token-based custom auth.
• Known abuse cases, compliance requirements, or public endpoint exposure.
• Desired response format and error handling conventions.
• Whether the API uses resources, spatie/laravel-query-builder, file uploads, signed URLs, or webhooks.

Procedure

1. Inspect the API surface from routes/api.php, route groups, middleware, controllers, form requests, resources, policies, guards, and exception handling. Note which endpoints are public, authenticated, tenant-scoped, admin-only, or webhook-driven.
2. Check validation and authorization in Laravel-native locations first. Prefer FormRequest classes, policy methods, gates, route model binding constraints, signed routes, and explicit authorization checks over ad-hoc controller logic.
3. Focus on common Laravel API risks: inline validation, mass-assignment exposure, unsafe $fillable or $guarded, over-broad API resources, user-controlled filters and sorts, weak pagination defaults, unconstrained uploads, and inconsistent exception rendering.
4. Review abuse controls and data exposure. Check throttling, token issuance, pagination caps, webhook signature verification, replay protection, rate-limited jobs, and whether hidden or sensitive attributes leak through serialization or toArray().
5. If the API uses Sanctum or Passport, review token ability checks, stateful vs stateless assumptions, CSRF/session crossover risks, and revocation or rotation handling. If it handles webhooks, explicitly review signature verification and idempotency.
6. Return findings under Critical issues, Hardening improvements, and Tests to add. Point each recommendation to the Laravel file or layer where the fix belongs, and prefer concrete changes such as FormRequest, policy, middleware, resource, cast, or hidden-attribute updates.
7. Keep the answer practical and prioritized. Do not give generic API security advice that is not tied to the actual Laravel implementation.

Output expectations: return prioritized Laravel-specific issues first, then concrete fixes and tests to add, not a generic API security checklist.

Examples

Prompt 1:

Use api-hardening-patterns on our public Laravel API. Focus on validation, authorization, throttling, and resource/data exposure.

Prompt 2:

Review these Sanctum-protected endpoints for abuse resistance and safer error handling. Suggest concrete Laravel fixes, not just generic advice.

JSON:

{
  "skill": "api-hardening-patterns",
  "context": {
    "auth": "sanctum",
    "exposure": "public",
    "focus": ["validation", "authorization", "rate_limiting", "error_contracts"],
    "files": ["routes/api.php", "app/Http/Controllers/Api", "app/Http/Requests"],
    "concerns": ["resource_exposure", "pagination_limits", "token_abilities"]
  }
}

Code example:

public function store(StorePostRequest $request): PostResource
{
    $this->authorize('create', Post::class);

    return new PostResource(Post::create($request->validated()));
}

Smoke test

Run the skill on a Laravel API controller with inline validation, missing policy checks, unsafe resource serialization, and unlimited pagination. Verify that the response returns concrete Laravel fixes such as FormRequest, policy, middleware, resource, or model-visibility changes instead of generic security advice.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: me-shaon
• Source: me-shaon/agent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.