How do I install Polar?

Polar is a local plugin. Install it using npm package: polar-mcp-unofficial and add the generated configuration snippet to your AI app's MCP config file. Then restart your AI app.

Is Polar safe to use?

Polar was flagged by MCP Marketplace's security scan, scoring 4.2/10 (high risk). It has 3 high or critical findings to review. Review the security report on this page carefully before installing it.

What credentials does Polar need?

Polar requires the following credentials or environment variables: POLAR_CLIENT_ID, POLAR_CLIENT_SECRET, POLAR_REDIRECT_URI, POLAR_TOKEN_PATH, POLAR_PRIVACY_MODE, POLAR_CACHE, POLAR_CACHE_PATH, POLAR_NO_CACHE. You can find setup instructions on the server detail page.

What AI apps work with Polar?

Polar uses the Model Context Protocol (MCP) and works with any MCP-compatible AI app, including Claude, ChatGPT / Codex, Gemini, Copilot, Cursor, and more.

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Polar MCP Server

by davidmosiah

Developer ToolsUse Caution4.2Local

Free

Privacy-first unofficial Polar AccessLink v4 MCP server for AI health, sleep and training agents.

About

Privacy-first unofficial Polar AccessLink v4 MCP server for AI health, sleep and training agents.

Security Report

4.2

Use Caution4.2High Risk

Polar MCP is a well-designed local-first health data connector with solid authentication and privacy controls. The codebase demonstrates good security practices around OAuth token handling, privacy mode enforcement, and restricted file permissions. Minor code quality issues and broad error handling do not significantly impact security posture. Supply chain analysis found 3 known vulnerabilities in dependencies (0 critical, 3 high severity). Package verification found 1 issue.

4 files analyzed · 9 issues found

Security scores are indicators to help you make informed decisions, not guarantees. Always review permissions before connecting any MCP server.

Permissions Required

This plugin requests these system permissions. Most are normal for its category.

env_vars

Check that this permission is expected for this type of plugin.

HTTP Network Access

Connects to external APIs or services over the internet.

File System Read

Reads files on your machine. Normal for tools that analyze or process local data.

File System Write

Writes or modifies files on your machine. Check that this is expected for the tool.

file_delete

Check that this permission is expected for this type of plugin.

What You'll Need

Set these up before or after installing:

Polar OAuth client ID. Optional when configured with polar-mcp-server setup.Optional

Environment variable: POLAR_CLIENT_ID

Polar OAuth client secret. Prefer polar-mcp-server setup so this secret is stored in ~/.polar-mcp/config.json instead of MCP client config.Required

Environment variable: POLAR_CLIENT_SECRET

Redirect URI configured in the Polar AccessLink admin. Optional when configured with polar-mcp-server setup.Optional

Environment variable: POLAR_REDIRECT_URI

Optional local path for OAuth tokens. Defaults to ~/.polar-mcp/tokens.json.Optional

Environment variable: POLAR_TOKEN_PATH

Optional payload mode: summary, structured, or raw. Defaults to structured. raw means full Polar AccessLink payloads for supported endpoints.Optional

Environment variable: POLAR_PRIVACY_MODE

Optional SQLite cache toggle. Set to true or sqlite to enable.Optional

Environment variable: POLAR_CACHE

Optional local SQLite cache path. Defaults to ~/.polar-mcp/cache.sqlite.Optional

Environment variable: POLAR_CACHE_PATH

Set to true to bypass the in-memory HTTP response cache (60s TTL for GET only). POST/PUT/DELETE and 4xx/5xx responses are never cached regardless.Optional

Environment variable: POLAR_NO_CACHE

How to Install

Add this to your MCP configuration file:

{
  "mcpServers": {
    "io-github-davidmosiah-polarmcp": {
      "env": {
        "POLAR_CACHE": "your-polar-cache-here",
        "POLAR_NO_CACHE": "your-polar-no-cache-here",
        "POLAR_CLIENT_ID": "your-polar-client-id-here",
        "POLAR_CACHE_PATH": "your-polar-cache-path-here",
        "POLAR_TOKEN_PATH": "your-polar-token-path-here",
        "POLAR_PRIVACY_MODE": "your-polar-privacy-mode-here",
        "POLAR_REDIRECT_URI": "your-polar-redirect-uri-here",
        "POLAR_CLIENT_SECRET": "your-polar-client-secret-here"
      },
      "args": [
        "-y",
        "polar-mcp-unofficial"
      ],
      "command": "npx"
    }
  }
}