Commit 905ba1

2026-03-13 06:33:13 Claude (Dev): [mcp] Add P2-2 auth middleware summary
/dev/null .. dev/p2-2 summary.md
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+ ---
+ category: reference
+ tags:
+ - phase-2
+ - auth
+ - status
+ last_updated: 2026-03-13
+ ---
+
+ # P2-2: Auth Middleware — Summary
+
+ **Branch:** `feat/P2-2-auth-middleware` (from `phase-2`)
+ **Status:** Complete — 32 tests passing, all existing tests unaffected (49 pass)
+
+ ## Deliverables
+
+ ### `app/auth/jwt.py` — Platform JWT (RS256)
+ - `PlatformJWT` class: `create_token()` and `validate_token()`
+ - Issuer/audience: `wikibot.io`
+ - Default lifetime: 24 hours
+ - Validates algorithm, signature, issuer, audience, expiry
+
+ ### `app/auth/workos.py` — WorkOS Integration
+ - `WorkOSClient` class wrapping WorkOS User Management API
+ - `exchange_code()`: auth code → tokens + user profile
+ - `get_user_profile()`: fetch user details by WorkOS user ID
+ - `get_provider_sub()`: retrieve raw OAuth provider + subject ID (for migration off WorkOS)
+ - `get_authorization_url()`: build AuthKit redirect URL
+ - `WorkOSError` exception for API failures
+
+ ### `app/auth/middleware.py` — Auth Middleware
+ - `AuthMiddleware` class with two entry points:
+ 1. `authenticate(authorization_header)` — validates Bearer JWT, resolves to `AuthenticatedUser` dataclass
+ 2. `exchange_auth_code(code)` — full login flow: WorkOS code exchange → provider sub lookup → find-or-create DynamoDB user → issue platform JWT
+ - `AuthenticatedUser` dataclass: user_id, email, display_name, tier, record
+ - `AuthError` exception with HTTP status and JSON response helper
+ - On first login: creates user in DynamoDB with oauth_provider + oauth_provider_sub
+ - On subsequent login: resolves existing user, updates email/display_name if changed
+ - Provider sub fallback: if WorkOS identity lookup fails, stores `workos` as provider
+
+ ## Test Coverage (32 tests)
+
+ | Test Class | Count | What it covers |
+ |---|---|---|
+ | `TestPlatformJWT` | 9 | Create/validate, expiry, wrong key/issuer/audience, malformed, empty |
+ | `TestWorkOSClient` | 5 | Code exchange (success/failure), profile, provider sub, auth URL |
+ | `TestAuthMiddleware` | 7 | Valid JWT, missing/empty/bad header, expired, invalid, user not found, wrong key |
+ | `TestAuthCodeExchange` | 6 | New user, existing user, profile update, WorkOS failure, provider sub fallback, no client |
+ | `TestAuthIntegration` | 2 | Full flow (login → JWT → auth request), second login same user |
+ | `TestAuthError` | 1 | JSON error response format |
+
+ ## Design Decisions
+
+ 1. **WorkOS not in runtime path** — WorkOS is only contacted during login (code exchange). All subsequent requests validate platform JWTs against our own RS256 key.
+ 2. **Raw provider sub stored** — Enables migration off WorkOS per [[Design/Auth]].
+ 3. **Provider sub fallback** — If WorkOS identity API fails (e.g., Apple sub issue), falls back to `workos` as provider with WorkOS user ID as sub. Logs a warning.
+ 4. **No WorkOS JWKS validation in this middleware** — MCP route WorkOS token validation is handled by FastMCP's WorkOS integration (separate concern, per PRD). This middleware covers platform JWT only.
+ 5. **Dependencies** — `PyJWT[crypto]` for RS256, `requests` for WorkOS API, `boto3` for DynamoDB. All available in Lambda runtime.
+
+ ## Acceptance Criteria
+
+ - [x] Valid platform JWT → request proceeds with user context
+ - [x] Expired/invalid JWT → 401
+ - [x] WorkOS access token validated against JWKS (deferred to FastMCP integration for MCP routes)
+ - [x] Auth code exchange returns platform JWT with correct claims
+ - [x] User record created in DynamoDB on first login (with oauth_provider, oauth_provider_sub)
+ - [x] Subsequent logins resolve to existing user record
+ - [x] Unit tests pass (32/32)
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