Best for
- Teams already using GrowthBook who want agents to manage flags and experiments
- MCP users who want an authenticated, auditable API passthrough
- Operators of self-hosted instances
G
GrowthBook MCP Server
Official
Official GrowthBook MCP server: skill loader + authenticated API passthrough
GitHub source repository ↗
60FMRS · C
An officially maintained, deliberately thin GrowthBook MCP server: skills are bundled at build time and capability is a single generic API passthrough, with a uniform tool prefix to avoid ambiguity across multiple MCP servers. HTTP mode's OAuth and token-refresh handling is well thought out. Best for existing GrowthBook teams, but mutating calls rely on soft confirmation, so grant credentials carefully.
The official, lightweight MCP server for GrowthBook. It exposes three tools: listing and reading bundled GrowthBook agent skills (bundled at build time from the official skills repo), and a generic growthbook_call_api tool that passes authenticated REST calls through to the GrowthBook API (creating flags, getting experiments, and more). It supports stdio and an HTTP transport with OAuth 2.0 protected-resource metadata (RFC 9728 / RFC 6750), and skill tools can be disabled to expose capability-only mode.
Tools
growthbook_list_skills
List bundled GrowthBook agent skills (name + description)
growthbook_read_skill
Return the full skill markdown (workflow + guardrails)
growthbook_call_api
Authenticated REST passthrough to the GrowthBook API, supporting GET/POST/PUT/PATCH/DELETE
Setup
Install and build with npm (npm install && npm run build), then point your MCP client at the compiled server/index.js, or run the published package via npx @growthbook/mcp. GB_API_KEY (a GrowthBook API key or personal access token) is required; GB_API_URL is optional (defaults to https://api.growthbook.io). Building from source requires a sibling ../skills checkout or SKILLS_SRC. A multi-arch image is also available at ghcr.io/growthbook/growthbook-mcp.
claude_desktop_config.json
{
"mcpServers": {
"growthbook": {
"command": "npx",
"args": [
"@growthbook/mcp"
],
"env": {
"GB_API_KEY": "your_api_key_or_pat",
"GB_API_URL": "https://api.growthbook.io"
}
}
}
}
Fit and risk
Not for
- Users without GrowthBook
- Read-only browsing without a GrowthBook API key
- Environments that cannot tolerate agent-driven mutating API calls
Required permissions
- GB_API_KEY: a GrowthBook API key or personal access token (required, secret)
- GB_API_URL: API base URL (optional, defaults to https://api.growthbook.io)
- GB_HTTP_HEADER_*: extra request headers (e.g. Cloudflare Access tokens)
Risks and side effects
- growthbook_call_api is a generic passthrough; POST/PUT/PATCH/DELETE can mutate data, and the confirm-with-user rule is soft guidance, not a hard gate
- The API key is a sensitive credential that can act on the whole account if leaked
- HTTP mode should run on a trusted network or loopback; multi-tenant or public deployments should be fronted by your own gateway/auth
Troubleshooting
- 401 invalid_token: check that GB_API_KEY is valid; in HTTP mode the client should refresh the token
- 403 means the token was accepted but permissions are insufficient — not an invalid token
- 404 on self-hosted instances: verify GB_API_URL points to the right address
- Server refuses to start in HTTP mode: GB_MCP_URL must be set
- Skill tools missing: check whether GB_SKILLS_ENABLED is set to false/0
Use cases
Creating and managing feature flags through an AI agent
Fetching experiments and project data
Having agents follow workflows and guardrails from official skills
Remote MCP access to a self-hosted GrowthBook instance (HTTP + OAuth mode)