Developer integration

Hollow MCP

Status: Public integration

A self-hosted Model Context Protocol facade for Hollow services.

Hollow MCP gives MCP clients one Streamable HTTP endpoint for Hollow tools, authenticated per request with the caller’s own API key and scoped across Notes, Tasks, Calendar, Workbooks, Cascade, and Lumen.

Hollow MCP

Developer integration

Developer surface

One endpoint, caller-owned access

  • 01

    Streamable HTTP

    A standard JSON-RPC endpoint for initialize, tool discovery, and tool calls.

  • 02

    Per-caller identity

    Every request uses the caller’s own Hollow API key and owner context.

  • 03

    Hollow tools

    Search, Notes, Tasks, Calendar, Workbooks, Cascade, and Lumen tools in one facade.

  • 04

    Scoped permissions

    Tools require the API-key scope appropriate to the product they reach.

Give your agent a careful way into Hollow

Hollow MCP is available at mcp.projecthollow.com. Configure it from Hollow Developer Keys and keep approval set to ask.