# VytalLink

> Privacy-first platform connecting wearable health data (Apple Health, Google Health Connect) to AI assistants via MCP (Model Context Protocol). Your data stays on your phone.

VytalLink is a mobile app that acts as a local MCP server, exposing health metrics from Apple HealthKit and Google Health Connect to AI tools like Claude Desktop and ChatGPT. Users share access via a Word + PIN credential system — no cloud upload of health data.

## Product

- [Home](https://vytallink.xmartlabs.com/): Overview, features, and download links for iOS and Android
- [About](https://vytallink.xmartlabs.com/about.md): Mission, values, and the Xmartlabs team behind VytalLink
- [FAQ](https://vytallink.xmartlabs.com/faq.md): Common questions about the app and integrations

## Setup Guides

- [MCP Advanced Setup](https://vytallink.xmartlabs.com/mcp-setup.md): Connect any MCP-compatible AI agent to VytalLink (Claude Desktop, Cursor, VS Code, and more)
- [ChatGPT Setup](https://vytallink.xmartlabs.com/chatgpt-setup.md): Use the VytalLink custom GPT in ChatGPT
- [Claude Desktop Bundle Setup](https://vytallink.xmartlabs.com/claude-bundle-setup.md): Connect Claude Desktop using the pre-built one-click bundle

## Developers

**If you are building an integration, read this first:** [llms-full.txt](https://vytallink.xmartlabs.com/llms-full.txt) contains the complete MCP API reference — response formats, field names, units per metric, response examples for each tool, and integration gotchas that are not in the OpenAPI spec or the tools endpoint. The OpenAPI spec and /mcp/tools alone are not sufficient to correctly parse responses.

- [Developer Guide](https://vytallink.xmartlabs.com/developers.md): Build health data agents in 5 minutes — MCP tools reference, authentication flow
- [Agent Examples (TypeScript & Python)](https://github.com/xmartlabs/vytalLink/tree/main/examples): Complete working agents — clone, configure, run
- [Health Kit Starter Template](https://github.com/xmartlabs/vytallink-health-kit): Python starter kit with CLI, Jupyter notebooks, and built-in observability (Grafana, Jaeger, LangSmith) — structured foundation for hackathons and prototypes

## Important notes

- MCP tool calls must be sequential (no parallel calls). The server does not support concurrent requests.
- The VytalLink mobile app must be open on the user's phone for the MCP connection to work. The phone acts as the data source.

## Resources

- [GitHub Repository](https://github.com/xmartlabs/vytalLink): Source code, issues, and contributions
- [npm Package](https://www.npmjs.com/package/@xmartlabs/vytallink-mcp-server): MCP server proxy (`npm install -g @xmartlabs/vytallink-mcp-server`)
- [Architecture Blog Post](https://blog.xmartlabs.com/blog/blog-building-health-apps-mcp-llms/): How VytalLink works under the hood
- [Bug Reports & Feature Requests](https://github.com/xmartlabs/vytalLink/issues)
- Email: vytalLink@xmartlabs.com

## API & MCP Reference

- [Swagger UI (Interactive Docs)](https://api.vytallink.xmartlabs.com/docs/mcp): Browse and test MCP tools interactively
- [OpenAPI Schema (JSON)](https://api.vytallink.xmartlabs.com/openapi/schema.json): Machine-readable API spec
- [OpenAPI Schema (YAML)](https://api.vytallink.xmartlabs.com/openapi/schema.yaml): Machine-readable API spec
- [MCP Tools Endpoint](https://api.vytallink.xmartlabs.com/mcp/tools): Live list of available MCP tools (GET)
- [MCP Call Endpoint](https://api.vytallink.xmartlabs.com/mcp/call): Invoke MCP tools (POST)
- [OAuth Discovery](https://api.vytallink.xmartlabs.com/.well-known/oauth-authorization-server): OAuth 2.0 server metadata

## Full content

- [llms-full.txt](https://vytallink.xmartlabs.com/llms-full.txt): All pages concatenated for single-file consumption