v0.4.0: Production Hardening

Changelog

v0.4.0

Production Hardening

• Schema/argument validation — type checking, required fields, enum, min/max, unknown param rejection (#49)
• Per-agent rate limiting to protect backends from flooding (#29)
• Structured audit logging: session_id, user_id, response_size_bytes, backend_url, http_status (#23)

Proxy Engine

• Shared httpx.AsyncClient per process for connection pooling instead of per-call (#62)
• Client identity forwarded as X-MCP-Client-Name / X-MCP-Client-Version headers to backends (#27)
• Non-JSON responses (HTML/text) gracefully wrapped instead of erroring (#30)
• SSE keepalive heartbeat frame (#45)
• httpx follow_redirects enabled for 3xx responses (#63)

Fixes

• Docker Compose health checks on test-bench for correct startup ordering (#33)
• Incident mock dates relative to datetime.now() — no time-bomb (#59)
• Production Dockerfile switches from editable install to regular install (#61)
• MCP protocol version aligned to 2025-06-18 (#74)
• mcplex/main.py + version added (#73)
• Correct handler types in test_registry.py (#72)
• Static CI badge replaced with live GitHub Actions badge (#65)
• CODE_OF_CONDUCT enforcement email completed (#69)
• Notification Accept: text/event-stream returns SSE, not JSON (#76)
• pytest config (asyncio_mode, testpaths) added (#77)
• CI matrix now tests Python 3.11 and 3.12 (#75)
• E2E screenshot path corrected, dead code removed (#66, #67)
• README connector naming aligned with config (#71)

Docs

• Architecture doc, deployment guide, troubleshooting guide added (#48, #47)
• Config reference updated with full HTTP connector schema (#51)
• WBS completion statuses corrected (#64)

Tests

• 75 total tests (+31): HTTP proxy (13), integration (7), rate limiter (5), validation (6)
• 9/9 Playwright E2E tests passing across all 4 backends