Polar MCP 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. Visit polar-mcp-server.n-neuhaeusel.workers.dev
2. Click "Connect with Polar" and authorize with your Polar account
3. Copy the MCP Server URL you receive
4. In Claude: Settings → Integrations → Add MCP Server
5. Paste the URL and 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
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
"Session expired"	Visit /authorize again to create a new session
"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 stored in Cloudflare KV with 24-hour expiration
• Each user gets their own isolated 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