intervals-training-bridge

An MCP server that lets Claude Code read your intervals.icu training data and write planned workouts to your intervals.icu calendar. If your calendar syncs to Garmin Connect, those workouts appear on your watch.

The bridge is deliberately mechanical. It fetches and writes data; all the training judgement stays with you and Claude.

Tools

dryRun defaults

push_workout, update_workout and delete_workout all default to dryRun: true. A dry run reports what would be written and changes nothing. Claude should only pass dryRun: false after you have explicitly approved that specific change.

Warning: dryRun: false writes to your real intervals.icu calendar, which syncs to Garmin Connect and onto your watch. delete_workout cannot be undone. Always review the dry run first.

Each workout stays in one metric family: all pace or all power. Mixing them breaks intervals.icu's load and time-in-zone calculations. Workouts can be pushed for run and bike.

Related MCP server: garmin-claude-mcp

Setup

1. Get an intervals.icu API key

In intervals.icu, open Settings, then Developer Settings, and create an API key.

2. Create a settings file

Create config/intervals.env in your project:

INTERVALS_API_KEY=
INTERVALS_ATHLETE_ID=

Paste your key after the =. INTERVALS_ATHLETE_ID is optional. Leave it blank to use the owner of the API key. This file holds a live API key, so keep it out of version control. Add it to your project's .gitignore:

config/intervals.env

3. Add the server to Claude Code

Add this to .mcp.json in your project:

{
  "mcpServers": {
    "intervals-training-bridge": {
      "command": "npx",
      "args": [
        "-y",
        "intervals-training-bridge@^0.2",
        "--stdio",
        "--settings-file",
        "config/intervals.env"
      ]
    }
  }
}

Relative settings-file paths resolve against the directory Claude Code launches the server from. As an alternative to the flag, set the INTERVALS_ENV_FILE environment variable to the file's path; the flag wins if both are given.

Restart Claude Code, approve the server, and ask it for your recent training.

Optional settings

These go in the same settings file.

• LOGS_PATH: a directory to write bridge.log to. Logs always go to stderr, which Claude Code captures. With --stdio, no log file is written unless you set this.

• INTERVALS_TIMEOUT_MS: how long to wait for intervals.icu before giving up, in milliseconds. Defaults to 10000 (10 seconds); must be more than 0.

• TIMEZONE: the time zone that decides what "today" is, for example Europe/London or America/New_York. Leave it out to use your computer's time zone.

Requirements

Node.js 20 or later.

Development

npm install
npm run build
npm test

Licence

MIT. See LICENSE.