mcp

# PostHog MCP Documentation: https://posthog.com/docs/model-context-protocol ## Use the MCP Server ### Quick install You can install the MCP server automatically into Cursor, Claude, Claude Code, VS Code and Zed by running the following command: ``` npx @posthog/wizard@latest mcp add ``` ### Manual install 1. Obtain a personal API key using the MCP Server preset [here](https://app.posthog.com/settings/user-api-keys?preset=mcp_server). 2. Add the MCP configuration to your desktop client (e.g. Cursor, Windsurf, Claude Desktop) and add your personal API key ```json { "mcpServers": { "posthog": { "command": "npx", "args": [ "-y", "mcp-remote@latest", "https://mcp.posthog.com/mcp", // You can replace this with https://mcp.posthog.com/sse if your client does not support Streamable HTTP "--header", "Authorization:${POSTHOG_AUTH_HEADER}" ], "env": { "POSTHOG_AUTH_HEADER": "Bearer {INSERT_YOUR_PERSONAL_API_KEY_HERE}" } } } } ``` ### Example Prompts - What feature flags do I have active? - Add a new feature flag for our homepage redesign - What are my most common errors? ### Data residency The MCP server is hosted on a Cloudflare worker, this can be located outside of the EU / US, so there is no gaurantee that the data will be processed solely within a specific region. ### Using self-hosted instances If you're using a self-hosted instance of PostHog, you can specify a custom base URL by adding the `POSTHOG_BASE_URL` [environment variable](https://developers.cloudflare.com/workers/configuration/environment-variables) when running the MCP server locally or on your own infrastructure, e.g. `POSTHOG_BASE_URL=https://posthog.example.com` # Development To run the MCP server locally, run the following command: ``` pnpm run dev ``` And replace `https://mcp.posthog.com/mcp` with `http://localhost:8787/mcp` in the MCP configuration. ## Project Structure This repository is organized to support multiple language implementations: - `typescript/` - TypeScript implementation of the MCP server & tools - `schema/` - Shared schema files generated from TypeScript ### Development Commands - `pnpm run dev` - Start development server - `pnpm run schema:build:json` - Generate JSON schema for other language implementations - `pnpm run lint && pnpm run format` - Format and lint code ### Adding New Tools See the [tools documentation](typescript/src/tools/README.md) for a guide on adding new tools to the MCP server. ### Environment variables - Create `.dev.vars` in the root - Add Inkeep API key to enable `docs-search` tool (see `Inkeep API key - mcp`) ``` INKEEP_API_KEY="..." ``` ### Configuring the Model Context Protocol Inspector During development you can directly inspect the MCP tool call results using the [MCP Inspector](https://modelcontextprotocol.io/docs/tools/inspector). You can run it using the following command: ```bash npx @modelcontextprotocol/inspector npx -y mcp-remote@latest http://localhost:8787/mcp --header "\"Authorization: Bearer {INSERT_YOUR_PERSONAL_API_KEY_HERE}\"" ``` Alternatively, you can use the following configuration in the MCP Inspector: Use transport type `STDIO`. **Command:** ``` npx ``` **Arguments:** ``` -y mcp-remote@latest http://localhost:8787/mcp --header "Authorization: Bearer {INSERT_YOUR_PERSONAL_API_KEY_HERE}" ```