LaunchDarkly local MCP server

Overview

This topic describes how to get started with the LaunchDarkly local Model Context Protocol (MCP) server.

Get started

To get started, you need an API access token with permission to execute any of the MCP tools available. Then, you need to add the MCP server definition to your AI client.

You also need a JavaScript runtime that supports ECMAScript 2020 or newer.

Authentication

First, create an API access token:

1. Click the gear icon in the left sidenav to view Organization settings.

2. Click Authorization.

3. In the “Access tokens” section, click Create token.

4. Give your token a human-readable Name.

5. Assign a Role to the token by choosing one from the menu.

   • The LaunchDarkly MCP server provides tools for managing flags and AgentControl configs, so your token should have permission to create, read, update, and delete flags and AgentControl configs in the projects you want to work in. We recommend that you use a token with a Writer base role, a LaunchDarkly Developer preset role, or another role that provides this access.

6. Click Save token. The new token appears in the Authorization page.

7. Copy and save the token somewhere secure. After you leave this page, the token is obscured.

To learn more, read Creating API access tokens.

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[
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  {
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    "effect": "allow",
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    "actions": ["*"],
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    "resources": ["proj/${roleAttribute/projectKey}:env/*:flag/*"]
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  },
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  {
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    "effect": "allow",
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    "actions": ["*"],
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    "resources": ["proj/${roleAttribute/projectKey}:env/*:aiconfig/*"]
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  },
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  {
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    "effect": "allow",
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    "actions": ["viewProject"],
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    "resources": ["proj/${roleAttribute/projectKey}"]
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  }
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]

Installation methods

You can install the LaunchDarkly MCP server in any AI client that supports the MCP protocol. For most AI clients, this means creating or updating an MCP server .json configuration file. LaunchDarkly customers on the EU or Federal instances of LaunchDarkly may want to use this method so they can include the correct server URLs.

Here’s what the .json file looks like:

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{
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  "mcpServers": {
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    "LaunchDarkly": {
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      "command": "npx",
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      "args": [
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        "-y", "--package", "@launchdarkly/mcp-server", "--", "mcp", "start",
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        "--api-key", "api-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
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      ]
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    }
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  }
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}

Replace api-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx with your API access token.

Follow the instructions below to install the MCP configuration to Cursor, Claude, or Copilot. For other IDEs, refer to your client’s instructions to learn where this configuration is located.

Run the MCP server from a local build

Optionally, you can run LaunchDarkly’s MCP server from a local build instead of from your AI client.

First, install and build the MCP server:

$
git clone git@github.com:launchdarkly/mcp-server.git
$
$
npm install
$
npm run build

Then, configure your server definition to reference your local clone. For example:

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{
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  "mcpServers": {
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    "LaunchDarkly": {
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      "command": "node",
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      "args": [
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        "/path/to/mcp-server/bin/mcp-server.js", "start",
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        "--api-key", "api-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
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      ]
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    }
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  }
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}

Enable the MCP server

Depending on your client, after you update your .json configuration file, you may have additional steps to enable the LaunchDarkly MCP server:

• You may need to restart your AI client in order for the updates to the configuration file to take effect.

• You may need to toggle on the LaunchDarkly MCP server configuration. For example, in Cursor you must enable each MCP server separately:

  

Restrict usage

You can specify additional options in your server configuration if you want to restrict the MCP server’s access to your LaunchDarkly account.

To give the MCP server only read-only access, we recommend using both of the following options:

• When you create your API access token, specify a Reader base role, or another role with read-only access.
• In your server configuration, add "--scope", "read" to the args array.

To enable only specific tools in your server configuration, add "--tool", "<tool>" to the args array for each tool you want to enable. For example:

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{
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  "mcpServers": {
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    "LaunchDarkly": {
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      "command": "npx",
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      "args": [
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        "-y", "--package", "@launchdarkly/mcp-server", "--", "mcp", "start",
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        "--tool", "create-feature-flag", "--tool", "update-feature-flag",
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        "--api-key", "api-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
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      ]
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    }
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  }
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}