Tools

MCP server

AI agents like Claude Code can create feature flags, turn them on and write the code that checks them through Flagbearer's MCP server:

https://mcp.flagbearer.dev

Connect an agent

Add the server with just its URL. The first time the agent uses it, Flagbearer opens in your browser. Pick the organization it can use and the access, Editor or Viewer, and click Connect.

  • Claude Code: run claude mcp add --transport http flagbearer https://mcp.flagbearer.dev, then /mcp, and choose flagbearer to sign in.
  • Claude.ai and Claude Desktop: add a custom connector with the URL https://mcp.flagbearer.dev.

The agent appears on the organization's API tokens tab as a connected app. Disconnect it there to end its access right away.

With a personal API token

For clients that can't sign in through the browser:

  1. Open your organization's API tokens tab and create a token. Pick Editor so the agent can create and change flags.

  2. Add the server with the token as a header. In Claude Code:

    claude mcp add --transport http flagbearer https://mcp.flagbearer.dev \
      --header "Authorization: Bearer fb_pat_…"

For a team, commit an .mcp.json that reads each person's own token from their environment, so no secret is in the repository:

{
  "mcpServers": {
    "flagbearer": {
      "type": "http",
      "url": "https://mcp.flagbearer.dev",
      "headers": { "Authorization": "Bearer ${FLAGBEARER_TOKEN}" }
    }
  }
}

Other MCP clients take the same URL and header in their own settings.

Tools

ToolWhat it does
list_organizationsThe organizations you belong to
list_applicationsAn organization's applications
list_flagsAn application's flags, on or off with their rollout, everywhere
create_flagCreates a flag, off in every environment
set_flagTurns a flag on or off in one environment
generate_flag_typesThe typed flag keys file for a TypeScript project, which the agent saves
get_sdk_docsThese SDK docs for React, the browser, Node, Python, Go, Java, .NET, Ruby, Rust, C++ or PHP, with an environment's client key

Before an agent writes code that checks a flag, it's told to read the SDK docs for the platform the code runs on, so it follows the same guidance you see here. It never gets a server key: those are shown once, in the dashboard.

Safeguards

  • Who gets a flag. Turning a flag on without a percentage reaches only the environment's testers. The agent is told to ask whether it should be on for everyone.
  • Production. The agent must confirm with you before changing the production environment.
  • Access. The agent works in the one organization you picked, as you, capped at the access you picked. It stops working if you leave the organization.
  • Limits. Each token can make 60 changes a minute.