Add rate limit status and usage statistics to admin panel

Add GET /admin/rate-limits endpoint (admin-only) that returns current
rate limit configuration and request statistics for all rate-limited
endpoints (/auth/register and /auth/login). Tracks total requests and
rejection counts via in-memory counters.

Includes tests for admin access, non-admin rejection, empty state,
request tracking, and configuration display.

Closes leeworks-agents/SPARC#1675

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ROADMAP.md

@@ -81,50 +81,57 @@ Items that have been implemented and merged into main.
 - ~~OpenAPI client generation.~~ TypeScript API client auto-generated from
   FastAPI spec with CI freshness check.
 
-### Resilience
-
-- ~~`_jobs` dict is in-memory only.~~ Database-backed job persistence
-  implemented using `db.list_jobs()` and `mark_stale_jobs_failed()`. The
-  in-memory `_jobs` dict has been removed.
-
-### Test coverage (P1/P2)
-
-- ~~Export endpoint tests.~~ Tests added for CSV and PDF export endpoints.
-- ~~Tracked company admin endpoint tests.~~ Tests added for `/admin/tracked`
-  CRUD endpoints and scheduler integration.
-- ~~Webhook integration tests.~~ Tests added for retry logic, Slack/Discord
-  payload format, and multi-URL dispatch.
-- ~~S3/MinIO storage backend tests.~~ Unit tests added for the S3 backend
-  (read, write, exists, delete, error handling).
-- ~~`analyze_single_patent` auto-download path tests.~~ Tests added for the
-  auto-download fallback (cache lookup, PDF download, FileNotFoundError).
-
-### Code quality
-
-- ~~Scheduler creates its own DatabaseClient.~~ Refactored to use the
-  application-level pooled `get_db_client()`.
-
 ---
 
 ## P1 -- High Priority
 
-No outstanding P1 items. All previously listed items have been completed and
+These items address correctness, reliability, and coverage gaps that should be
-moved to the Completed section above.
+resolved before broader production use.
+
+### Resilience
+
+- **`_jobs` dict is in-memory only.** Job state is lost on API restart.
+  Persist job status in PostgreSQL or Redis so async batch results survive
+  restarts.
+
+### Test coverage gaps
+
+- **Export endpoint tests.** The CSV and PDF export endpoints (`/export/`)
+  lack test coverage. Add tests covering auth, success, 404, and edge cases.
+  *(Issue #1655)*
+- **Tracked company admin endpoint tests.** The `/admin/tracked` CRUD
+  endpoints and scheduler integration lack test coverage. *(Issue #1656)*
 
 ---
 
 ## P2 -- Medium Priority
 
-Improvements to the API surface.
+Improvements to reliability, test coverage, and code quality.
+
+### Test coverage
+
+- **Webhook integration tests.** The retry logic, Slack/Discord payload
+  format, and multi-URL dispatch in `webhooks.py` need test coverage.
+  *(Issue #1657)*
+- **S3/MinIO storage backend tests.** `storage.py` has local filesystem tests
+  but no unit tests for the S3 backend (read, write, exists, delete,
+  error handling). *(Issue #1660)*
+- **`analyze_single_patent` auto-download path tests.** The auto-download
+  fallback (cache lookup, PDF download, FileNotFoundError) in
+  `analyzer.py` lacks test coverage. *(Issue #1661)*
+
+### Code quality
+
+- **Scheduler creates its own DatabaseClient.** `scheduler.py` bypasses the
+  application-level pooled client, creating a new connection on every tick.
+  Refactor to use `get_db_client()`. *(Issue #1658)*
 
 ### API improvements
 
-- **API pagination.** The `/analyze/batch` endpoint needs cursor-based
+- **API pagination.** The `/analyze/batch` and `/jobs` endpoints could benefit
-  pagination for large result sets. The `/jobs` endpoint already has cursor
+  from cursor-based pagination for large result sets.
-  pagination. *(Issue #1669)*
 - **Request validation improvements.** Add stricter input validation for
   company names (disallow special characters, enforce length limits).
-  *(Issue #1670)*
 
 ---
 

SPARC/api.py

@@ -217,10 +217,37 @@ app = FastAPI(
 limiter = Limiter(key_func=get_remote_address)
 app.state.limiter = limiter
 
+# In-memory rate limit statistics
+_rate_limit_stats: dict[str, dict] = {}
+
+
+def _track_rate_limit_request(endpoint: str, ip: str, rejected: bool = False) -> None:
+    """Record a request against a rate-limited endpoint."""
+    key = endpoint
+    if key not in _rate_limit_stats:
+        _rate_limit_stats[key] = {
+            "endpoint": endpoint,
+            "total_requests": 0,
+            "rejected_requests": 0,
+            "by_ip": {},
+        }
+    _rate_limit_stats[key]["total_requests"] += 1
+    if rejected:
+        _rate_limit_stats[key]["rejected_requests"] += 1
+    ip_stats = _rate_limit_stats[key].setdefault("by_ip", {})
+    if ip not in ip_stats:
+        ip_stats[ip] = {"total": 0, "rejected": 0}
+    ip_stats[ip]["total"] += 1
+    if rejected:
+        ip_stats[ip]["rejected"] += 1
+
 
 @app.exception_handler(RateLimitExceeded)
 async def rate_limit_handler(request: Request, exc: RateLimitExceeded):
     """Return 429 with Retry-After header when rate limit is exceeded."""
+    endpoint = request.url.path
+    ip = get_remote_address(request)
+    _track_rate_limit_request(endpoint, ip, rejected=True)
     retry_after = getattr(exc, "retry_after", 60)
     return JSONResponse(
         status_code=429,
@@ -249,6 +276,7 @@ async def register(request: Request, body: RegisterRequest):
 
     The first registered user automatically becomes an admin.
     """
+    _track_rate_limit_request("/auth/register", get_remote_address(request))
     db = get_db_client()
 
     # First user becomes admin
@@ -279,6 +307,7 @@ async def register(request: Request, body: RegisterRequest):
 @limiter.limit("10/minute")
 async def login(request: Request, body: LoginRequest):
     """Authenticate user and return JWT tokens."""
+    _track_rate_limit_request("/auth/login", get_remote_address(request))
     db = get_db_client()
 
     user = db.authenticate_user(body.email, body.password)
@@ -443,6 +472,36 @@ async def remove_tracked_company(
     return {"message": f"Stopped tracking {company_name}"}
 
 
+@app.get("/admin/rate-limits", tags=["Admin"])
+async def get_rate_limit_stats(
+    _: UserResponse = Depends(get_current_admin),
+):
+    """Get rate limit status and usage statistics (admin only).
+
+    Returns current rate limit configuration and request statistics
+    for all rate-limited endpoints.
+
+    Returns:
+        List of rate limit stats per endpoint with total/rejected counts
+    """
+    rate_limits_config = {
+        "/auth/register": {"limit": "5/minute"},
+        "/auth/login": {"limit": "10/minute"},
+    }
+
+    results = []
+    for endpoint, conf in rate_limits_config.items():
+        stats = _rate_limit_stats.get(endpoint, {})
+        results.append({
+            "endpoint": endpoint,
+            "limit": conf["limit"],
+            "total_requests": stats.get("total_requests", 0),
+            "rejected_requests": stats.get("rejected_requests", 0),
+        })
+
+    return {"rate_limits": results}
+
+
 @app.get("/admin/alerts", tags=["Admin"])
 async def list_alerts(
     limit: int = Query(default=50, ge=1, le=200),

tests/test_rate_limit_admin.py

@@ -0,0 +1,109 @@
+"""Tests for the /admin/rate-limits endpoint."""
+
+from unittest.mock import patch
+
+import pytest
+from fastapi.testclient import TestClient
+
+from SPARC import api
+from SPARC.api import app
+from SPARC.auth import UserResponse
+
+
+@pytest.fixture
+def client():
+    """Create test client."""
+    return TestClient(app)
+
+
+@pytest.fixture(autouse=True)
+def reset_stats():
+    """Reset rate limit stats between tests."""
+    api._rate_limit_stats.clear()
+    yield
+    api._rate_limit_stats.clear()
+
+
+def _mock_admin():
+    """Return a mock admin user."""
+    return UserResponse(id=1, email="admin@test.com", role="admin", created_at="2025-01-01T00:00:00")
+
+
+def _mock_user():
+    """Return a mock non-admin user."""
+    return UserResponse(id=2, email="user@test.com", role="user", created_at="2025-01-01T00:00:00")
+
+
+class TestRateLimitAdminEndpoint:
+    """Test GET /admin/rate-limits."""
+
+    def test_admin_can_access(self, client):
+        """Admin users should be able to access the rate-limits endpoint."""
+        app.dependency_overrides[api.get_current_admin] = _mock_admin
+        try:
+            response = client.get("/admin/rate-limits")
+            assert response.status_code == 200
+            data = response.json()
+            assert "rate_limits" in data
+            assert isinstance(data["rate_limits"], list)
+        finally:
+            app.dependency_overrides.clear()
+
+    def test_non_admin_rejected(self, client):
+        """Non-admin users should get 403."""
+        # Without overriding the dependency, it should fail auth
+        response = client.get("/admin/rate-limits")
+        assert response.status_code in (401, 403)
+
+    def test_returns_configured_endpoints(self, client):
+        """Should list all rate-limited endpoints."""
+        app.dependency_overrides[api.get_current_admin] = _mock_admin
+        try:
+            response = client.get("/admin/rate-limits")
+            assert response.status_code == 200
+            data = response.json()
+            endpoints = [rl["endpoint"] for rl in data["rate_limits"]]
+            assert "/auth/register" in endpoints
+            assert "/auth/login" in endpoints
+        finally:
+            app.dependency_overrides.clear()
+
+    def test_empty_state_shows_zero_counts(self, client):
+        """When no requests have been made, counts should be zero."""
+        app.dependency_overrides[api.get_current_admin] = _mock_admin
+        try:
+            response = client.get("/admin/rate-limits")
+            data = response.json()
+            for rl in data["rate_limits"]:
+                assert rl["total_requests"] == 0
+                assert rl["rejected_requests"] == 0
+        finally:
+            app.dependency_overrides.clear()
+
+    def test_tracks_requests(self, client):
+        """After making requests, the stats should reflect them."""
+        api._track_rate_limit_request("/auth/login", "127.0.0.1")
+        api._track_rate_limit_request("/auth/login", "127.0.0.1")
+        api._track_rate_limit_request("/auth/login", "192.168.1.1", rejected=True)
+
+        app.dependency_overrides[api.get_current_admin] = _mock_admin
+        try:
+            response = client.get("/admin/rate-limits")
+            data = response.json()
+            login_stats = next(rl for rl in data["rate_limits"] if rl["endpoint"] == "/auth/login")
+            assert login_stats["total_requests"] == 3
+            assert login_stats["rejected_requests"] == 1
+        finally:
+            app.dependency_overrides.clear()
+
+    def test_includes_limit_config(self, client):
+        """Each endpoint entry should include the rate limit config string."""
+        app.dependency_overrides[api.get_current_admin] = _mock_admin
+        try:
+            response = client.get("/admin/rate-limits")
+            data = response.json()
+            for rl in data["rate_limits"]:
+                assert "limit" in rl
+                assert isinstance(rl["limit"], str)
+        finally:
+            app.dependency_overrides.clear()