debate/.planning/phases/01-core-infrastructure-security/01-03-SUMMARY.md

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	duration	completed
01-core-infrastructure-security	03	security	slowapi fastapi-csrf-protect rate-limiting cors security-headers middleware	phase provides 01-01 FastAPI application structure, pydantic-settings configuration phase provides 01-02 PostgreSQL database, async session factory, get_db dependency	Rate limiting at 100 requests/minute per IP CSRF protection with secure cookie configuration Security headers middleware (HSTS, X-Frame-Options, X-XSS-Protection) TrustedHostMiddleware for Host header validation CORS configuration with credential support Database health check endpoint at /api/v1/health/db	01-04 01-05 02 03	added patterns slowapi fastapi-csrf-protect security-middleware-stack rate-limit-exempt-decorator dependency-injection-for-csrf	created modified backend/app/core/security.py backend/app/api/deps.py backend/app/main.py backend/app/api/v1/endpoints/health.py	Security headers applied via custom middleware (Starlette @app.middleware pattern) Rate limiting uses in-memory storage for development, Redis URL configurable for production Health endpoints exempt from rate limiting via @limiter.exempt decorator CSRF validation available as optional dependency injection pattern	Middleware ordering: TrustedHost (outermost) -> CORS -> Rate limiting -> Security headers (innermost) deps.py centralizes FastAPI dependencies with re-exports for cleaner imports Database health check with SELECT 1 query pattern	3min	2026-01-25

Phase 01 Plan 03: Security Middleware Stack Summary

FastAPI security middleware with 100/min rate limiting, CSRF protection, trusted host validation, CORS, and security headers (HSTS, X-Frame-Options, X-XSS-Protection, Referrer-Policy)

Performance

• Duration: 3 min
• Started: 2026-01-25T20:17:05Z
• Completed: 2026-01-25T20:20:07Z
• Tasks: 2
• Files modified: 4 (plus 1 migration file linting fix)

Accomplishments

• Rate limiting configured at 100 requests/minute using slowapi with in-memory storage
• CSRF protection configured with secure cookie settings (httponly, samesite=lax, secure=true)
• Security headers middleware adds HSTS, X-Content-Type-Options, X-Frame-Options, X-XSS-Protection, Referrer-Policy
• TrustedHostMiddleware rejects requests with invalid Host headers (returns 400)
• Database health check endpoint verifies PostgreSQL connectivity

Task Commits

Each task was committed atomically:

1. Task 1: Configure rate limiting and CSRF protection - 81486fc (feat)
2. Task 2: Apply security middleware and update health endpoint - 0d1a008 (feat)

Files Created/Modified

• backend/app/core/security.py - Rate limiter and CSRF settings configuration
• backend/app/api/deps.py - Dependency injection utilities with get_db re-export and CSRF validation
• backend/app/main.py - Security middleware stack applied in correct order
• backend/app/api/v1/endpoints/health.py - Database health check endpoint with rate limit exemption

Decisions Made

• Used Starlette's @app.middleware("http") for security headers instead of separate middleware class (simpler for static headers)
• Health endpoints marked @limiter.exempt to avoid rate limiting health checks from monitoring systems
• CSRF validation is optional dependency injection pattern (validate_csrf) rather than middleware, allowing per-endpoint control
• Used get_db re-export pattern in deps.py for cleaner import paths in endpoints

Deviations from Plan

Auto-fixed Issues

1. [Rule 3 - Blocking] Fixed ruff linting errors in migration file

• Found during: Task 2 (ruff check backend/)
• Issue: Pre-existing migration file had trailing whitespace, long lines, and old Union syntax
• Fix: Reformatted file to comply with ruff rules (line length, modern type hints)
• Files modified: backend/alembic/versions/de1460a760b0_create_build_table.py
• Verification: ruff check backend/ passes with no errors
• Committed in: 0d1a008 (Task 2 commit)

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Total deviations: 1 auto-fixed (1 blocking) Impact on plan: Linting fix was necessary for verification to pass. No scope creep.

Issues Encountered

None - plan executed as expected.

User Setup Required

None - no external service configuration required. Rate limiting uses in-memory storage by default.

Next Phase Readiness

• Security middleware stack complete and verified
• Ready for 01-04-PLAN.md (Caddy reverse proxy and automatic HTTPS)
• CSRF protection configured but not enforced on endpoints yet (ready for form submission protection when needed)

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Phase: 01-core-infrastructure-security Completed: 2026-01-25