intervals-kit 0.1.3

MCP server, CLI, and Python library for the Intervals.ICU fitness tracking API

intervals-kit

MCP server, CLI, and Python library for the Intervals.ICU fitness tracking API. Exposes activity data (power curves, HR curves, streams, intervals, segments, file downloads) to AI assistants via the Model Context Protocol, and as a command-line tool for scripting and bulk data access.

Requirements

• Python 3.10+
• uv — recommended for running the package

Installation

pip install intervals-kit

Or with uv:

uv pip install intervals-kit

Configuration

The package reads credentials from environment variables or a config file.

Environment variables (recommended):

export INTERVALS_API_KEY=your_api_key      # From intervals.icu → Settings → API Key
export INTERVALS_ATHLETE_ID=iXXXXXX       # Your athlete ID (visible in the URL when logged in)

Config file (~/.config/intervals-kit/config.toml):

api_key = "your_api_key"
athlete_id = "iXXXXXX"
base_url = "https://intervals.icu"   # optional

Environment variables take precedence over the config file.

Usage as MCP Server (Claude Code / Claude Desktop)

The easiest way — no installation needed:

{
  "mcpServers": {
    "intervals-icu": {
      "command": "uvx",
      "args": ["intervals-kit"],
      "env": {
        "INTERVALS_API_KEY": "your_api_key",
        "INTERVALS_ATHLETE_ID": "iXXXXXX"
      }
    }
  }
}

Once configured, Claude can directly query your training data:

"How many rides did I do last month?" "What was my best 5-minute power in March?" "Download my activities as a CSV for Q1 2025."

Available MCP Tools

Tool	Description
list_activities	List activities for a date range
get_activity	Get full details for a single activity
search_activities	Search by name or tag
update_activity	Update name, description, type, or RPE
get_activity_intervals	Get lap/split data
get_activity_streams	Get second-by-second time-series (power, HR, cadence, …)
get_power_curve	Mean-maximal power curve for an activity
get_hr_curve	Heart rate curve for an activity
get_pace_curve	Pace curve for running/swimming
get_best_efforts	Best efforts detected in an activity
get_activity_segments	Matched Strava/Intervals segments
get_activity_map	GPS track (lat/lon)
get_athlete_power_curves	Best power curves across a date range
get_athlete_hr_curves	Best HR curves across a date range

For large data (streams >1 hour, CSV exports, binary files) the MCP tools return metadata and tell Claude to use the CLI for the actual download.

Usage as CLI

uvx --from intervals-kit intervals-icu-tools --help

Activity commands

# List activities for a date range (JSON to stdout)
uvx --from intervals-kit intervals-icu-tools list-activities --oldest 2025-01-01 --newest 2025-03-31

# Save to a file instead of stdout
uvx --from intervals-kit intervals-icu-tools -o ./data list-activities --oldest 2025-01-01 --newest 2025-03-31

# Get a single activity
uvx --from intervals-kit intervals-icu-tools get-activity i136292802

# Search by name or tag (# prefix for exact tag match)
uvx --from intervals-kit intervals-icu-tools search-activities "long ride"
uvx --from intervals-kit intervals-icu-tools search-activities "#race" --full

# Update fields
uvx --from intervals-kit intervals-icu-tools update-activity i136292802 --perceived-exertion 7 --description "Felt strong"

Sub-resource commands

# Lap/interval data
uvx --from intervals-kit intervals-icu-tools get-intervals i136292802

# Time-series streams (specify types to limit size)
uvx --from intervals-kit intervals-icu-tools -o ./data get-streams i136292802 --types watts,heartrate,cadence

# Power / HR / pace curves
uvx --from intervals-kit intervals-icu-tools get-power-curve i136292802
uvx --from intervals-kit intervals-icu-tools get-hr-curve i136292802
uvx --from intervals-kit intervals-icu-tools get-pace-curve i136292816  # running activity

# Best efforts, segments, GPS map
uvx --from intervals-kit intervals-icu-tools get-best-efforts i136292802
uvx --from intervals-kit intervals-icu-tools get-segments i136292802
uvx --from intervals-kit intervals-icu-tools -o ./data get-activity-map i136292802

File download commands

# Download original upload / FIT / GPX file
uvx --from intervals-kit intervals-icu-tools -o ./data download-activity-file i136292802 --type fit
uvx --from intervals-kit intervals-icu-tools -o ./data download-activity-file i136292802 --type gpx

# Bulk CSV export for a date range
uvx --from intervals-kit intervals-icu-tools -o ./data download-activities-csv --oldest 2025-01-01 --newest 2025-03-31

Aggregate curves

# Best power/HR/pace curves across all activities in a date range
uvx --from intervals-kit intervals-icu-tools get-athlete-power-curves --oldest 2025-01-01 --newest 2025-03-31
uvx --from intervals-kit intervals-icu-tools get-athlete-hr-curves --oldest 2025-01-01 --newest 2025-03-31
uvx --from intervals-kit intervals-icu-tools get-athlete-pace-curves --oldest 2025-01-01 --newest 2025-03-31

Global options

Option	Default	Description
-o / --output-dir	. (stdout)	Directory to save output files
-f / --format	json	Output format: json or csv

Exit codes

Code	Meaning
0	Success
1	Auth error or general API error
2	Rate limit exceeded (retryable)
3	Download / network error (retryable)
4	Resource not found

Usage as Python Library

import asyncio
from intervals_kit import IntervalsService, load_config

async def main():
    svc = IntervalsService(load_config())

    # List March 2025 activities
    activities = await svc.list_activities("2025-03-01", "2025-03-31")
    rides = [a for a in activities if a.type == "Ride"]
    print(f"Rides: {len(rides)}, Runs: {len(activities) - len(rides)}")

    # Get power curve for first ride
    if rides:
        curve = await svc.get_power_curve(rides[0].id)
        print(f"Power curve keys: {list(curve.keys())}")

asyncio.run(main())

Development

# Clone and install with dev dependencies
git clone https://github.com/jrsassen/intervals-kit
cd intervals-kit
uv sync

# Run tests
uv run pytest

# Run a single test
uv run pytest tests/test_service.py -k test_name

# Run integration tests against the real API (requires credentials)
uv run pytest -m integration

Architecture

Three interfaces share one service layer — see docs/SPECIFICATIONS.md for the full architecture and src/intervals_kit/cli_tools.md for the complete CLI reference intended for LLM agents.

MCP Tools (FastMCP)  ──┐
CLI Commands (Click)  ──┼──▶  service.py  ──▶  client.py  ──▶  Intervals.ICU API
Python import        ──┘

Source layout:

src/intervals_kit/
├── errors.py        # Exception types
├── models.py        # Pydantic models
├── config.py        # Configuration loading
├── client.py        # HTTP client (auth, error mapping, streaming)
├── exporters.py     # JSON serialization
├── service.py       # All business logic
├── mcp_server.py    # FastMCP tool definitions
└── cli/             # Click command definitions