growthbook MCP Server

Use This MCP server To

Create new feature flags for my projects Fetch details of existing experiments Update feature flag settings Delete obsolete feature flags List available skills and workflows Access GrowthBook API data securely Run experiments and analyze results

README

GrowthBook MCP Thin

A thin MCP server for GrowthBook with four tools:

Tool	Purpose
`growthbook_list_skills`	List top-level skill entry points (name + description)
`growthbook_read_skill`	Return a listed skill or qualified child workflow (`feature-flags` or `feature-flags/references/flag-create`)
`growthbook_api_read`	Authenticated GET passthrough to the GrowthBook API
`growthbook_api_write`	Authenticated POST/PUT/PATCH/DELETE passthrough

Competence lives in the skills repo and is bundled at build time. Capability is split into read vs write API tools (no per-endpoint formatters) so clients can honor readOnlyHint / destructiveHint correctly.

Tools are prefixed with growthbook_ so they stay unambiguous when a client has multiple MCP servers loaded.

Install / run

npm install
npm run build

Point your MCP client at the compiled entrypoint:

{
  "mcpServers": {
    "growthbook": {
      "command": "node",
      "args": ["/absolute/path/to/growthbook-mcp/server/index.js"],
      "env": {
        "GB_API_KEY": "your_api_key_or_pat",
        "GB_API_URL": "https://api.growthbook.io"
      }
    }
  }
}

Or run the published package:

npx @growthbook/mcp

Environment variables

Variable	Required	Default	Purpose
`GB_API_KEY`	Yes for stdio; optional for HTTP OAuth	—	GrowthBook API key or personal access token
`GB_API_URL`	No	`https://api.growthbook.io`	API base URL (self-hosted) and default OAuth AS issuer
`GB_MCP_TRANSPORT`	No	`stdio`	`stdio` or `http`
`GB_MCP_PORT`	No	`3333`	HTTP listen port (when transport=http)
`GB_MCP_HOST`	No	`127.0.0.1`	HTTP bind host
`GB_MCP_URL`	Yes for HTTP	—	Public MCP base URL stamped into OAuth resource metadata (server refuses to start in HTTP mode without it)
`GB_OAUTH_ISSUER`	No	`GB_API_URL`	GrowthBook OAuth AS issuer URL
`GB_HTTP_HEADER_*`	No	—	Extra request headers (e.g. `GB_HTTP_HEADER_CF_ACCESS_TOKEN`)
`GB_SKILLS_ENABLED`	No	`true`	Set to `false` / `0` to disable skill tools

growthbook-mcp FAQ

Can I use this to create and manage feature flags?

Yes — it lets your AI create, update, and retrieve feature flags using GrowthBook's API.

Can I use this to run experiments and get experiment data?

Yes — it supports fetching experiment details and managing them through GrowthBook's API.

Which apps can I use this MCP server with?

It can be connected to any MCP-compatible client that supports custom servers, such as Claude Desktop, Cursor, or ChatGPT with MCP support.

Do I need a GrowthBook API key to use this server?

Yes — you must provide a GrowthBook API key or personal access token to authenticate requests.

How hard is it to set up this server?

Setup involves pasting a small configuration snippet and environment variables, so it is a copy-paste-config level task.

Does this server support both reading and writing data?

Yes — it provides separate tools for authenticated read and write access to GrowthBook's API.

Can I run this server remotely over HTTP?

Yes — it supports HTTP mode with OAuth 2.0 protection for remote connections.