@tokenfactory/acc-mcp-server

Agent Control Center MCP server. Stdio-transport subprocess spawned by @tokenfactory/acc-runner alongside each Claude Code session. Exposes six read-only ACC tools (query_tasks, query_prs, query_cost, query_decisions, query_runners, query_approvals) over the Model Context Protocol and telemeters every tool call to acc.mcp_tool_calls.

How agents reach it

The runner writes a .mcp.json into the task working directory before spawning Claude Code:

{
  "mcpServers": {
    "acc": {
      "command": "npx",
      "args": [
        "-y", "@tokenfactory/acc-mcp-server",
        "--task-id", "T-12345",
        "--runner-id", "local-priyas-mbp",
        "--access-token", "<runner JWT>"
      ]
    }
  }
}

Claude Code auto-discovers the server, lists the tools at session start, and the agent can call any of the six during a task. Each call writes one row to acc.mcp_tool_calls (latency, request args, response summary) via POST /api/mcp/record-tool-call — service-role only, so the agent surface cannot fabricate telemetry.

Tool catalog

The catalog is a duplicate of api/chat/_tools.ts (the Ask-ACC chat contract). A parity test in tests/tools.test.ts cross-checks the two arrays so additions in one place fail CI in the other.

Environment

| Var | Notes | | --- | --- | | SUPABASE_URL / ACC_SUPABASE_URL | Project URL | | SUPABASE_ANON_KEY / ACC_SUPABASE_ANON_KEY | Anon key for the user-scoped client | | ACC_PUBLIC_URL | ACC API host. Defaults to https://acc.techarch.dev. Overridable via --public-url. | | ACC_MCP_ACCESS_TOKEN | Runner JWT. Overridable via --access-token (visible in ps). |

Security notes

• The runner's JWT is passed as a CLI arg. Visible in ps output for the subprocess lifetime — acceptable for v0.5-C1 because the runner itself owns the process tree, but tracked for v0.6 hardening (env-only handoff or token-broker pattern).
• Telemetry writes go through POST /api/mcp/record-tool-call, which validates the JWT and uses the service-role to call acc.record_mcp_tool_call. Direct RPC access is denied.

Versioning

Pin @modelcontextprotocol/sdk exactly — MCP SDK churns on minor releases. Update via the standard checklist in docs/acc/MCP_SERVER.md (peer-dep cycle, schema-shape diff, parity test against the latest Claude Code release).