By name: fastapi-debug description: Debug and troubleshoot ettametta's FastAPI application. Use when investigating middleware issues, authentication failures, route errors, dependency injection problems, CORS, rate limiting, or OpenAPI issues.
FastAPI Debugging
Quick Diagnostics
curl http://localhost:8000/health
curl http://localhost:8000/openapi.json | jq '.paths | keys' | head -30
curl http://localhost:8000/metrics | head -20
Middleware Stack (outermost first)
| Order | Middleware | Purpose |
|---|---|---|
| 1 | GZipMiddleware | Compress responses >= 1KB |
| 2 | SecurityHeadersMiddleware | HSTS, X-Frame-Options, nosniff (prod only) |
| 3 | TracingMiddleware | X-Request-ID generation/propagation |
| 4 | RequestLoggingMiddleware | Log method, path, status, response time |
| 5 | CORSMiddleware | CORS with configurable origins |
Route Structure
All routes under /api/v1/ via v1_router = APIRouter(prefix="/v1").
| Module | Prefix |
|---|---|
| routes/auth.py | /auth |
| routes/discovery.py | /discovery |
| routes/video_transform.py | /video |
| routes/video_generate.py | /video |
| routes/video_jobs.py | /video/jobs |
| routes/publish/ | /publish (sub-routers: oauth, publisher, scheduler, analytics, accounts, opencli) |
| routes/analytics.py | /analytics |
| routes/monetization.py | /monetization |
| routes/billing.py | /billing |
| routes/settings.py | /settings |
| routes/nexus.py | /nexus |
| routes/security.py | /security |
| routes/llm.py | /llm |
| routes/ws.py | /ws |
| routes/health.py | /health |
| routes/admin.py | /admin |
Special: /health (direct), /static (file serving), /metrics (Prometheus).
Key Files
| File | Purpose |
|---|---|
| src/api/main.py | App init, middleware, startup events |
| src/api/utils/auth.py | get_current_user, admin_required, JWT decode |
| src/api/utils/security.py | Password hashing (bcrypt), JWT creation |
| src/api/utils/limiter.py | slowapi rate limiter with tiered keys |
| src/api/utils/database.py | get_db() dependency |
| src/api/utils/api_responses.py | success_response, error_response, PaginatedResponse |
| src/api/utils/errors.py | ErrorCode enum, ErrorResponse, factory functions |
| src/api/exception_handlers.py | Global exception handler registration |
| src/api/config/settings.py | Pydantic Settings singleton |
Authentication
OAuth2 password bearer. Flow:
- Extract JWT from
Authorization: Bearer <token> - Check Redis blacklist (
token_blacklistset) - Decode with python-jose (HS256, SECRET_KEY)
- Extract
sub(email), query UserDB
Route-level: Depends(get_current_user) or Depends(admin_required).
Error Handling
Custom hierarchy: APIError -> ValidationError(422), NotFoundError(404), AuthenticationError(401), AuthorizationError(403), RateLimitError(429), ExternalServiceError(502), ConflictError(409).
Standard format:
{"error": {"code": "ERROR_CODE", "message": "...", "timestamp": "...", "details": {}}}
Catch-all persists to SelfHealingAuditDB.
Rate Limiting
| Tier | Limit |
|---|---|
| FREE | 100/hr |
| PRO/PREMIUM/BASIC | 500/hr |
| SOVEREIGN/STUDIO | 5000/hr |
Startup Events
- Init Redis cache (FastAPICache)
- Seed default monitored niches
- Start hot-reload listener
- sync_all_vitals() recovery
- ConsistencySentinel loop
- Agent Zero state recovery
Common Issues
CORS errors
Check: docker compose exec api env | grep CORS_ORIGINS
401 on valid token
Expired (24h default)? Blacklisted? SECRET_KEY mismatch?
Rate limit 429
Check tier. Wait or adjust LIMIT_* env vars.
Request ID missing
TracingMiddleware generates UUID4. If missing, middleware not registered.
Health check fails
/health does SELECT 1. DB down = 500.