launchflag-mcp

launchflag-mcp

MCP server for LaunchFlag. It lets a coding agent create a feature flag, ship the risky path dark behind it, and flip it later without a deploy.

Seven tools, one token, no state.

Hosted, or local

Hosted (recommended). Nothing to install. Point your client at https://launchflag.dev/mcp with your API token (lfk_…) in the Authorization header.

Local (stdio). Runs on your machine and talks to the same API over HTTPS. Useful when your client does not speak Streamable HTTP, or when you self-host LaunchFlag.

npx launchflag-mcp

Either way, the fastest setup is one command from your project root, which also writes the key and the agent skill: npx launchflag init --token lfk_….

Env vars

Variable	Required	Default	What it is
LAUNCHFLAG_TOKEN	yes	none	Your API token (lfk_…), from the dashboard Install page. The server exits if it is missing.
LAUNCHFLAG_URL	no	https://launchflag.dev	Base URL of the LaunchFlag instance. Set it only if you self-host.

The token is a secret. Keep the file that holds it out of git.

The seven tools

Tool	What it does
list_flags	Every flag with its dev, staging and prod state, fail mode and variants.
create_flag	Creates a flag OFF in all three environments and returns the snippet to wrap the new path in.
set_flag	Turns a flag on or off, or changes who it targets, in one environment.
promote_flag	Copies one environment's config forward: dev to staging, or staging to prod.
delete_flag	Deletes a flag, once the code paths behind it are gone.
emergency_off	Kill switch: disables every non-essential flag in the project at once, or lifts it.
list_projects	Your projects and their env keys.

Claude Code

Hosted:

claude mcp add --transport http launchflag https://launchflag.dev/mcp --header "Authorization: Bearer lfk_…"

Local, in .mcp.json:

{
  "mcpServers": {
    "launchflag": {
      "command": "npx",
      "args": ["-y", "launchflag-mcp"],
      "env": { "LAUNCHFLAG_TOKEN": "lfk_…" }
    }
  }
}

Cursor

.cursor/mcp.json, hosted:

{
  "mcpServers": {
    "launchflag": {
      "type": "http",
      "url": "https://launchflag.dev/mcp",
      "headers": { "Authorization": "Bearer lfk_…" }
    }
  }
}

Swap in the command/args/env block above to run it locally instead.

Codex

codex mcp add launchflag --url https://launchflag.dev/mcp --header "Authorization: Bearer lfk_…"

Local:

codex mcp add launchflag --env LAUNCHFLAG_TOKEN=lfk_… -- npx -y launchflag-mcp

Docs

Full agent guide, including the skill file and the flag conventions agents should follow: launchflag.dev/docs/agents.

Questions or a bug: [e-mail].

MIT licensed.