← Projects
MIT · Open source

mcp-harness-fme

Manage Harness FME (Split.io) feature flags & segments from any MCP client — list, toggle, kill

Documentation →GitHub ↗

Features

  • 38 tools — covers workspaces, environments, feature flags, flag definitions, segments, rule-based segments, and change requests.
  • Kill & restore — instantly kill a flag to force all traffic to the default treatment, or restore it with a single tool call.
  • Safety guard — every destructive operation (delete, kill, archive, disable) requires confirm: true, preventing accidental changes.
  • Rule-based segments — create, update, enable, disable, and submit change requests for rule-based segments per environment.
  • Change request flow — submit segment definition changes with optional approvers for teams that require approval gates.
  • Zero-config startup — reads MCP_HARNESS_FME_API_KEY from the environment and exits immediately if it is missing.

Install

Add to your MCP client config (see Usage below), or install globally to run manually:

npx --yes @kud/mcp-harness-fme@latest

Set the environment variable MCP_HARNESS_FME_API_KEY to your Harness FME API key before starting the server.

Usage

This is a standard stdio MCP server — it works with any MCP client (Claude Desktop, Claude Code, Cursor, Windsurf, Cline, Zed, …). Add it to your client's MCP config:

{
  "mcpServers": {
    "harness-fme": {
      "command": "npx",
      "args": ["--yes", "@kud/mcp-harness-fme@latest"],
      "env": {
        "MCP_HARNESS_FME_API_KEY": "your_api_key"
      }
    }
  }
}

Most clients read this mcpServers shape — Claude Desktop's config file, Cursor's .cursor/mcp.json, Windsurf, Cline, and so on. For Claude Code, there's a CLI shortcut:

claude mcp add --transport stdio --scope user harness-fme \
  --env MCP_HARNESS_FME_API_KEY=your_api_key \
  -- npx --yes @kud/mcp-harness-fme@latest

To enable the get_flag_url deep-link tool, also set two optional keys — add them to the env block above (or as extra --env flags for the CLI). See Configuration for where to find their values.

"env": {
  "MCP_HARNESS_FME_API_KEY": "your_api_key",
  "MCP_HARNESS_FME_ACCOUNT_ID": "your_account_id",
  "MCP_HARNESS_FME_ORG_GUID": "your_org_guid"
}

Leave them out and every other tool still works — get_flag_url just reports what's missing.

Read the documentation →