PostHog MCP

Use the MCP Server

Quick install

You can install the MCP server automatically into popular clients 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.

2. Add the MCP configuration to your desktop client (e.g. Cursor, Windsurf, Claude Desktop) and add your personal API key

{
  "mcpServers": {
    "posthog": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote@latest",
        "https://mcp.posthog.com/sse",
        "--header",
        "Authorization:${POSTHOG_AUTH_HEADER}"
      ],
      "env": {
        "POSTHOG_AUTH_HEADER": "Bearer {INSERT_YOUR_PERSONAL_API_KEY_HERE}"
      }
    }
  }
}

Using EU cloud or self-hosted instances

If you're using PostHog EU cloud or a self-hosted instance, you can specify a custom base URL by adding the POSTHOG_BASE_URL environment variable when running the MCP server locally or on your own infrastructure, e.g. POSTHOG_BASE_URL=https://eu.posthog.com

Here are some examples of prompts you can use:

• What feature flags do I have active?

• Add a new feature flag for our homepage redesign

• What are my most common errors?

Development

To run the MCP server locally, run the following command:

pnpm run dev

And replace https://mcp.posthog.com/sse with http://localhost:8787/sse in the MCP configuration.

Related MCP server: Featureflow MCP Server

Project Structure

This repository is organized to support multiple language implementations:

• typescript/ - TypeScript implementation (current)

• python/ - Python implementation (planned)

• schema/ - Shared schema files generated from TypeScript for cross-language compatibility

Development Commands

• pnpm run dev - Start development server

• pnpm run schema:build:json - Generate JSON schema for other language implementations

• pnpm run lint:fix - Format and lint code

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.

You can run it using the following command:

npx @modelcontextprotocol/inspector npx -y mcp-remote@latest http://localhost:8787/sse --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/sse --header "Authorization: Bearer {INSERT_YOUR_PERSONAL_API_KEY_HERE}"