Syncky: open protocol, reference agent and reference server

Syncky Health sends the Apple Health data you choose from your iPhone to your own AI agent (local MCP server) or your own server. The AI agent route is end-to-end encrypted. Your agent and your server can both write entries back into Health once you allow writing on the iPhone.

Client health-data envelopes are end-to-end encrypted (HPKE Auth + ChaCha20-Poly1305): the relay sees delivery metadata and emits plaintext hub notices, but sees no health values. The app can also send straight to a server the user runs, with no relay at all. The user's agent or server receives plaintext, and a chosen model sees what the agent supplies.

Get Syncky Health on the App Store or visit syncky.app.

Install for an MCP client

Requires Node.js ≥22.15 and npm. The npm package embeds its runtime packages and has no runtime dependencies. Start the local stdio server with:

npx -y @syncky/agent mcp

For a client whose JSON configuration uses mcpServers:

{"mcpServers":{"syncky":{"command":"npx","args":["-y","@syncky/agent","mcp"]}}}

Pair first using SKILL.md or the operator guide. Use the same SYNCKY_AGENT_HOME during setup and in the MCP client's environment when selecting a custom home. Grant only the read/write types you want to share. iOS background scheduling and an unlocked phone govern delivery; this is not a real-time feed.

Cursor

Add to Cursor

The default home is ~/.syncky-agent; add env.SYNCKY_AGENT_HOME only for a custom home, using the absolute path of the same initialized/paired home used by your receiver. JSON environment values do not expand $HOME or ~; use your actual path, including on Windows.

For manual configuration, merge this server into global ~/.cursor/mcp.json or project .cursor/mcp.json, preserving other servers:

{"mcpServers":{"syncky":{"command":"npx","args":["-y","@syncky/agent","mcp"]}}}

Cursor enables MCP tool approval by default. Do not auto-allow syncky_send or syncky_ack; approve only writes, diagnostics requests and access requests you intend. Cursor's mcp.json cannot disable individual tools, so this recipe leaves both mutating tools available and is not a read-only setup. You can toggle the whole server in Customize. A write is applied only when its type is in the app write allowance (device-wide) or granted to this agent at pairing, within the agent's write scope, and authorized by HealthKit (iOS write permission). The operator guide's security rules still apply. A queued write is not an applied write. MCP does not start a receiver or complete pairing; keep one receiver per home.

Claude Desktop

For manual local setup, the official MCP tutorial, linked through Anthropic's local-server documentation, specifies Settings → Developer → Edit Config. On macOS the file is ~/Library/Application Support/Claude/claude_desktop_config.json; on Windows it is %APPDATA%\Claude\claude_desktop_config.json. Merge this server, preserving other entries:

{"mcpServers":{"syncky":{"command":"npx","args":["-y","@syncky/agent","mcp"]}}}

Save, fully quit and restart Desktop to start the local stdio server. It runs under your user account. Inspect tools through + → Connectors or Local MCP servers settings; current Anthropic Help describes Settings → Desktop app → Manage Extensions and the older Settings → Extensions layout. Review permission requests and approve only intended operations. This re

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