cos: Skill for Claude Code

Fitness MCP setup (thin fetch-wrapper bridge :8011)

Why this exists / architecture

fitness is the second built-in add-on ("Fitness" — Apple Watch health ingestion + dashboard at /fitness/health, plus the athlete training profile + AI coach at /fitness). Like nutrition, it has no external repo and no sidecar: the server lives in this Cos checkout at mcp/fitness-server/server.mjs, and it is the same thin fetch wrapper archetype over the board's /api/fitness/* HTTP routes on CRM_BASE_URL. It makes no LLM calls — the coaching intelligence (training plans, weekly reviews, pre-workout briefs) lives on the board's /api/fitness/* routes (server-side Claude calls) and in the operator skill (/fitness-coach), not here.

Like nutrition, every write is add-on-gated — attributed to the agent via the x-actor header and blocked only when the add-on is disabled. The Apple-Watch ingest endpoint (POST /api/fitness/push) is the same: the MCP's push_health_data lands a batch of canonical entries, gated by the add-on toggle exactly like every other write.

It is a single Node stdio process and registers into Cos the same two ways the core servers do:

• Claude Code reaches it over HTTP via a supergateway + launchd BRIDGE on :8011 ($FITNESS_BRIDGE_PORT, label com.chiefofstaff.mcp-fitness, IN .mcp.json).
• Claude Cowork Desktop spawns it as a direct stdio command entry in claude_desktop_config.json — identical to how mcp-bridge-setup wires board/calendar/etc.

Claude Code   ──HTTP──> localhost:8011/mcp ──supergateway(launchd)──> node fitness-server (stdio)
                                                                          │ fetch (x-actor:agent)
                                                                          └──HTTP──> board /api/fitness/* (:3000)
Cowork Desktop ──spawns stdio directly──────────────────────────────────> node fitness-server   (§5)

This is an ADD-ON — its WRITES are GATED, its READS are open. The "Fitness" add-on must be ENABLED (Settings.addons.fitness.enabled in cases.json) for writes to land. A disabled add-on 404s every write (the board surfaces it here as a Not found — the fitness add-on may be disabled. tool error) while every GET read stays open, and its /fitness + /fitness/* nav pages 404 + hide. Enabling is itself a step (§6) — flip it from the board's /addons catalog (or PATCH /api/addons/fitness).