# unleash-mcp

An MCP server that lets a coding assistant create and manage Unleash feature flags. Handy when a change needs to sit behind a flag while you write it.

- MCP server · `type=mcp` · Claude Code, Codex, Cursor, GitHub Copilot, Windsurf (Devin Desktop), Cline, Zed, Gemini CLI · ★ 21
- Author: Unleash
- License: not stated · policy=link-only · description only; the file stays with the author
- Source: https://github.com/Unleash/unleash-mcp
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/mcp/unleash-mcp

## What it does

The server exposes tools that talk to the Unleash Admin API. An assistant can create a flag, look for one that already exists so you don't end up with duplicates, score the risk of a change, and get guidance on wrapping that change in a flag. Other tools return a flag's metadata, its recent edits from the event log, and an explanation of which strategies matched when the flag is evaluated against a context.

The intended order of work is: judge whether the change needs a flag, check for an existing one, create it, then pull the language-specific code for using it. Rollout tools cover percentage, segments, constraints and whether an environment is on; lifecycle tools complete, archive, revive or mark a flag stale.

You need Node.js 22 or higher, pnpm or npm, an Unleash instance and a personal access token allowed to create flags. No token, no server. An experimental option connects over HTTP to the remote MCP built into your Unleash instance, which has to be enabled there first. The `send_feedback` tool reports a broken call back to Unleash, and only after the user agrees; setting `UNLEASH_MCP_SEND_FEEDBACK=false` keeps it out of the tool list.

## Requirements
- Needs: Node.js (commands run via npx)
- Environment variables: `UNLEASH_BASE_URL`, `UNLEASH_PAT`, `UNLEASH_DEFAULT_PROJECT`, `UNLEASH_MCP_SEND_FEEDBACK`, `UNLEASH_FEEDBACK_URL`, `UNLEASH_MCP_CONFIG_DIR` — keys and tokens: ask the human for the values, never commit them or put them in shared files.

## Install

### Claude Code (native platform)

**Platform CLI**
```bash
claude mcp add --env UNLEASH_BASE_URL=<UNLEASH_BASE_URL> --env UNLEASH_PAT=<UNLEASH_PAT> --env UNLEASH_DEFAULT_PROJECT=<UNLEASH_DEFAULT_PROJECT> --env UNLEASH_MCP_SEND_FEEDBACK=<UNLEASH_MCP_SEND_FEEDBACK> --env UNLEASH_FEEDBACK_URL=<UNLEASH_FEEDBACK_URL> --transport stdio unleash-mcp -- npx -y @unleash/mcp
```
Replace <…> with your own values. 1 more environment variable is in the server README

### Codex

**Platform CLI**
```bash
codex mcp add unleash-mcp --env UNLEASH_BASE_URL=<UNLEASH_BASE_URL> --env UNLEASH_PAT=<UNLEASH_PAT> --env UNLEASH_DEFAULT_PROJECT=<UNLEASH_DEFAULT_PROJECT> --env UNLEASH_MCP_SEND_FEEDBACK=<UNLEASH_MCP_SEND_FEEDBACK> --env UNLEASH_FEEDBACK_URL=<UNLEASH_FEEDBACK_URL> -- npx -y @unleash/mcp
```
Replace <…> with your own values. 1 more environment variable is in the server README

### Cursor

**Config file**
File `.cursor/mcp.json`:
```json
{
    "mcpServers": {
        "unleash-mcp": {
            "command": "npx",
            "args": [
                "-y",
                "@unleash/mcp"
            ],
            "env": {
                "UNLEASH_BASE_URL": "<UNLEASH_BASE_URL>",
                "UNLEASH_PAT": "<UNLEASH_PAT>",
                "UNLEASH_DEFAULT_PROJECT": "<UNLEASH_DEFAULT_PROJECT>",
                "UNLEASH_MCP_SEND_FEEDBACK": "<UNLEASH_MCP_SEND_FEEDBACK>",
                "UNLEASH_FEEDBACK_URL": "<UNLEASH_FEEDBACK_URL>"
            }
        }
    }
}
```
Replace <…> with your own values. 1 more environment variable is in the server README

### GitHub Copilot

**Config file**
File `.vscode/mcp.json`:
```json
{
    "servers": {
        "unleash-mcp": {
            "type": "stdio",
            "command": "npx",
            "args": [
                "-y",
                "@unleash/mcp"
            ],
            "env": {
                "UNLEASH_BASE_URL": "<UNLEASH_BASE_URL>",
                "UNLEASH_PAT": "<UNLEASH_PAT>",
                "UNLEASH_DEFAULT_PROJECT": "<UNLEASH_DEFAULT_PROJECT>",
                "UNLEASH_MCP_SEND_FEEDBACK": "<UNLEASH_MCP_SEND_FEEDBACK>",
                "UNLEASH_FEEDBACK_URL": "<UNLEASH_FEEDBACK_URL>"
            }
        }
    }
}
```
Replace <…> with your own values. 1 more environment variable is in the server README

### Gemini CLI

**Platform CLI**
```bash
gemini mcp add -e UNLEASH_BASE_URL=<UNLEASH_BASE_URL> -e UNLEASH_PAT=<UNLEASH_PAT> -e UNLEASH_DEFAULT_PROJECT=<UNLEASH_DEFAULT_PROJECT> -e UNLEASH_MCP_SEND_FEEDBACK=<UNLEASH_MCP_SEND_FEEDBACK> -e UNLEASH_FEEDBACK_URL=<UNLEASH_FEEDBACK_URL> unleash-mcp npx -y @unleash/mcp
```
Replace <…> with your own values. 1 more environment variable is in the server README

## When to use it
- create a feature flag without opening the Unleash UI
- check whether a flag already exists and reuse it
- decide if a code change needs a flag at all
- see who changed a flag and when, per environment
- turn a flag off in one environment or drop its strategy

## Example prompts
- Evaluate this change and tell me whether it needs a feature flag
- Create a flag called `new-checkout` in the `web` project and show how to wrap the code
- Roll out `new-checkout` to 10 percent of users in staging

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