Milestone 2.5.G6.M1 — MCP Server Skeleton

Status: Completed (2026-08-25)
Goal: Track F — MCP Server Skeleton
Phase: 2.5 — Provider Generalization & Foundation
Estimated effort: 3 days
ADR: ADR-0050

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Why This Milestone Exists

Ship the MCP auth boundary, Streamable HTTP transport, and audit wiring against stub handlers before Phase 3 writers exist — same “build the seam first” pattern as the rest of Phase 2.5.

Non-Goals (enforced)

• Real memory read/write / DB coupling
• record_feedback / get_memory_lineage
• Independent OAuth authorization server or second identity system
• Independent MCP rate limiter (env reserved; enforcement is 3.5.E.4)

What shipped

• Service services/mcp-memory/ — official MCP Python SDK, FastAPI host, /health /ready
• Transport: Streamable HTTP (/mcp); stdio gated (IBEX_MCP_TRANSPORT=stdio + IBEX_MCP_ALLOW_STDIO)
• Auth: Bearer → AuthService.ValidateToken gRPC, fail closed; WWW-Authenticate + /.well-known/oauth-protected-resource
• Stub tools: search_memory, write_memory with strict schemas; tenant from token org_id
• ClickHouse ibex.mcp_tool_calls (000002) + async non-blocking audit emitter
• CI (pytest/ruff/bandit/coverage), Dockerfile, ADR-0050

Success signals

• MCP initialize / tools/list / tools/call against stubs (HTTP tests)
• Bearer validation via Auth gRPC seam; fail closed on auth outage
• Tool invocations emit org-scoped audit events (no secrets/content)
• Exactly two tools registered
• Repo guards / CI gates wired for the new Python service

Prerequisites

• Phase 2 exit (merged)
• Auth service gRPC contract stable