Polar Server

An MCP (Model Context Protocol) server for the Polar AccessLink API. Connect your Polar fitness data to Claude AI - access workouts, sleep analysis, recovery metrics, heart rate data, and more.

Quick Start (Public Instance)

No setup required! Use our hosted instance:

1. In Claude: Settings → Integrations → Add MCP Server
2. Enter the URL: https://polar-mcp-server.n-neuhaeusel.workers.dev/mcp
3. Claude will open an authorization window — log in with your Polar account
4. Start chatting about your fitness data!

Features

25 Tools Available

Category	Tools	Description
Exercises	get_exercises, get_exercise	Training data with HR, speed, zones
Exercise Export	get_exercise_fit, get_exercise_tcx, get_exercise_gpx	Export in FIT, TCX, GPX formats
Sleep	get_sleep, get_sleep_range	Sleep stages, score, duration
Recovery	get_nightly_recharge, get_nightly_recharge_range	ANS charge, HRV, breathing rate
Activity	get_daily_activity, get_daily_activity_range, get_activity_samples, get_activity_samples_range	Steps, calories, activity zones
Heart Rate	get_continuous_heart_rate, get_continuous_heart_rate_range	24/7 heart rate monitoring
Training Load	get_cardio_load, get_cardio_load_range, get_cardio_load_history	TRIMP, acute/chronic load
SleepWise	get_sleepwise_alertness, get_sleepwise_circadian_bedtime	Alertness predictions, optimal bedtime
Biosensing	get_body_temperature, get_skin_temperature, get_spo2	Temperature, SpO2 data
User	get_user_info, get_physical_info	Profile, VO2max, resting HR

Supported Devices

• Polar Pacer / Pacer Pro
• Polar Vantage V2 / V3
• Polar Vantage M / M2
• Polar Grit X / Grit X Pro / Grit X2 Pro
• Polar Ignite / Ignite 2 / Ignite 3
• Polar Unite
• And more...

Example Prompts

Once connected, ask Claude:

• "Show me my workouts from last week"
• "How was my sleep last night? Compare it to my weekly average"
• "Analyze my heart rate variability trends"
• "What's my current training load status?"
• "When should I go to bed tonight for optimal recovery?"
• "Export my last run as a GPX file"
• "How many steps did I take this month?"

Self-Hosting

Want to run your own instance? Two deployment options available:

Option 1: Cloudflare Workers (Recommended)

Prerequisites

• Cloudflare account
• Polar AccessLink API credentials

Setup

# Clone and install
git clone https://github.com/NelsonNew/polar-mcp-server.git
cd polar-mcp-server
npm install

# Create KV namespace
npx wrangler kv namespace create OAUTH_KV
# Copy the ID to wrangler.toml

# Set secrets
npx wrangler secret put POLAR_CLIENT_ID
npx wrangler secret put POLAR_CLIENT_SECRET

# Deploy
npm run deploy

After deploying, add the callback URL to your Polar app:

https://YOUR-WORKER.workers.dev/callback

Option 2: Local (Claude Desktop)

# Clone and build
git clone https://github.com/NelsonNew/polar-mcp-server.git
cd polar-mcp-server
npm install && npm run build

# Get access token
export POLAR_CLIENT_ID="your_client_id"
export POLAR_CLIENT_SECRET="your_client_secret"
npm run auth

Add to Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "polar": {
      "command": "node",
      "args": ["/path/to/polar-mcp-server/dist/index.js"],
      "env": {
        "POLAR_ACCESS_TOKEN": "your_access_token"
      }
    }
  }
}

API Reference

All tools use the Polar AccessLink API v3.

Tool	Endpoint	Description
get_user_info	/users/{id}	User profile
get_physical_info	/users/physical-information	VO2max, max HR, resting HR
get_exercises	/exercises	Last 30 days of workouts
get_exercise	/exercises/{id}	Single workout details
get_exercise_fit/tcx/gpx	/exercises/{id}/fit|tcx|gpx	Export formats
get_sleep	/users/sleep	Sleep data
get_nightly_recharge	/users/nightly-recharge	Recovery metrics
get_daily_activity	/users/activities	Daily activity
get_continuous_heart_rate	/users/continuous-heart-rate	24/7 HR
get_cardio_load	/users/cardio-load	Training load
get_sleepwise_alertness	/users/sleepwise/alertness	Alertness predictions
get_body_temperature	/users/biosensing/bodytemperature	Body temp
get_spo2	/users/biosensing/spo2	Blood oxygen

Troubleshooting

Error	Solution
"Polar API error (403)"	Re-authorize or check if data sync is complete
"Polar API error (404)"	Endpoint not available for your device/subscription
No exercise data	Sync your Polar device to Polar Flow app first

Privacy

• Your Polar credentials are never stored
• OAuth tokens are managed securely by the Cloudflare Workers OAuth provider
• Each user gets their own isolated MCP session
• No fitness data is logged or stored on our servers

Contributing

Contributions welcome! Please open an issue or PR.

License

MIT

Links

• Polar AccessLink API
• Polar Developer Portal
• MCP Protocol
• Cloudflare Workers