Intervals.icu MCP Server

A self-hosted, multi-tenant Model Context Protocol (MCP) server that exposes the Intervals.icu API — activities, events, wellness, power curves, gear, and custom items — as MCP tools for Claude. It runs as a remote, OAuth-authenticated connector at https://intervalsicu.farhoodlabs.com/mcp, where each user's Intervals.icu API key and athlete id are stored encrypted and looked up per request from their OAuth identity.

This is a fork of the upstream single-tenant project (mvilanova/intervals-mcp-server), reworked for remote multi-user operation.

How it fits together

The system is three services on one Kubernetes host (intervalsicu.farhoodlabs.com), deployed via Flux GitOps and sharing one CloudNativePG Postgres database:

Service	Path	What it does
intervalsicu-mcp (this repo)	/mcp	The MCP server. Verifies OAuth JWTs and serves Intervals.icu data as MCP tools over streamable-HTTP.
intervalsicu-mcp-ui	/portal	Portal where users sign in (Google via Better Auth) and set their Intervals.icu credentials; admins approve accounts.
intervalsicu-mcp-auth	/api/auth	Better Auth OAuth 2.1 server: dynamic client registration (DCR), PKCE, EdDSA-signed JWTs + JWKS, Google login.

Connection flow: the Claude connector self-registers at the auth server (DCR), the user logs in with Google, and Claude receives a JWT access token whose audience is the /mcp URL. This server verifies that JWT against the auth server's JWKS and resolves the caller's stored Intervals.icu credentials by the token subject. A user who hasn't been approved or hasn't set credentials gets a friendly "account isn't ready" message.

Connecting Claude

Add a custom remote connector in Claude pointing at:

https://intervalsicu.farhoodlabs.com/mcp

Name it without a dot — use intervals, not intervals.icu. Claude Desktop and mobile fail to load the tools if the connector name contains a dot. Claude handles registration and Google login for you. Your account must be approved in the portal and have Intervals.icu credentials set.

Available tools

get_activities, get_activity_details, get_activity_intervals, get_activity_streams, get_activity_messages, add_activity_message, get_events, get_event_by_id, add_or_update_event, delete_event, delete_events_by_date_range, get_wellness_data, get_athlete_power_curves, get_gear_list, get_custom_items, get_custom_item_by_id, create_custom_item, update_custom_item, delete_custom_item.

Local development

Requires Python 3.12+ and uv.

uv venv --python 3.12 && source .venv/bin/activate
uv sync --all-extras        # install with dev extras

uv run pytest               # tests (enforces a >=90% coverage gate)
ruff check .                # lint
mypy src tests              # type check

Run locally over stdio (single-user, using the env fallback credentials below):

python -m intervals_mcp_server.server

For local HTTP without OAuth, set MCP_TRANSPORT=http and leave MCP_ISSUER / MCP_RESOURCE / MCP_JWKS_URI unset — auth is disabled when those aren't all present, and tools use the API_KEY / ATHLETE_ID env fallback.

Environment variables

Local / single-user fallback (used only when there is no OAuth context):

• API_KEY — an Intervals.icu API key (Settings → API on intervals.icu).
• ATHLETE_ID — your athlete id, e.g. i12345 (from the intervals.icu URL). Must match i?\d+.
• INTERVALS_API_BASE_URL — optional, defaults to https://intervals.icu/api/v1.

Multi-tenant / deployment:

• DATABASE_URL — async Postgres DSN (postgresql+asyncpg://…) for the shared user store.
• INTERVALS_ENC_KEY — base64-encoded 32-byte AES-256-GCM key used to encrypt stored API keys. Shared with the UI service so both read/write the same ciphertext.
• MCP_ISSUER, MCP_RESOURCE, MCP_JWKS_URI — OAuth: token issuer, the /mcp resource URL, and the JWKS endpoint (an internal in-cluster URL, to bypass Cloudflare). Setting all three enables auth.
• MCP_TRANSPORT — stdio (default), sse, or http/streamable-http. Deployment uses http.
• MCP_STATELESS_HTTP, MCP_JSON_RESPONSE — HTTP tuning. The deployment sets both true (stateless + JSON) so the distributed connector can hit any replica; stateful/SSE breaks it.
• FASTMCP_HOST, FASTMCP_PORT, FASTMCP_LOG_LEVEL — HTTP bind + logging.

Deployment

Pushes to main trigger Gitea CI (.gitea/workflows/build.yaml): it runs the test suite with the coverage gate, then builds and pushes a container image to git.farh.net/farhoodlabs/intervalsicu-mcp. Flux reconciles the new image onto the cluster. Database migrations run as an Alembic (alembic upgrade head) initContainer before the server starts.

License

GNU General Public License v3.0 (inherited from the upstream project).