MostLogin MCP

Written By Penny Wang

Last updated About 13 hours ago

MostLogin MCP Server is a local API service provided by MostLogin to connect with MCP-compatible AI tools. It enables seamless integration between MostLogin and popular AI development tools such as Claude, Cursor, Codex, and OpenCode.

MostLogin client version 2.1.9 and above is required for MCP.

Once connected, you can use natural language commands to control MostLogin and perform the following key operations:

  • Create and launch browser profiles

  • Update browser fingerprints

  • Configure proxies

  • Manage sessions, cookies, User-Agent strings, and more

  • Execute other browser automation tasks

This integration significantly enhances AI-assisted development, testing, and automation workflows by allowing AI tools to interact with realistic browser environments just like a human user would.

Supported Tools

The MCP Server currently supports the following tools:

  • Claude (Claude Code)

  • Cursor

  • Codex

  • OpenCode

The General configuration applies to most tools. If you change values in the request headers, you will need to reconfigure the MCP based on the new values.

Configuration Methods

MostLogin offers two convenient configuration methods: Via Prompt and Via JSON.

1. Configure via Prompt (Recommended for Beginners)

  1. In the MostLogin MCP Server interface, go to the General tab.

  2. Click the Copy prompt button to copy the prompt text.

  3. Paste the prompt into your AI tool (Claude, Cursor, etc.) chat window.

  4. Follow the AI’s guided instructions to complete the setup.

This method is the simplest, as the AI will walk you through the process step by step.

2. Configure via JSON (For Advanced Users or Automated Deployments)

Copy the JSON configuration from the Configure MCP via Json section:

{
    "mostlogin": {
        "url": "http://127.0.0.1:30898/mcp",
        "headers": {
            "Authorization": "*******************"
        }
    }
}

Configuration Breakdown:

  • args: Includes the service address (default: http://127.0.0.1:30897/mcp), transport protocol, security settings, and authorization header.

  • env.AUTH_TOKEN: The authorization token provided by MostLogin (shown masked in the interface). Replace with your actual token.

How to Use:

  1. Click Copy code to copy the full JSON.

  2. Paste it into your AI tool’s MCP configuration section (Settings → MCP / Tools / Integrations).

  3. Save and test the connection.

Step-by-Step Setup (Cursor Example)

  1. Ensure MostLogin is running and the LocalAPI MCP Server is enabled.

  2. Open the MCP configuration area in Cursor.

  3. Choose “Add MCP Server” or the equivalent option.

  4. Paste either the Prompt or JSON configuration.

  5. Enter or verify the AUTH_TOKEN.

  6. Test the connection.

  7. Once successful, you can start using natural language commands such as:

    • “Create a new US Chrome browser profile with a residential proxy using MostLogin”

    • “Launch a fingerprint profile mimicking an iPhone 15”

    • “Update the current session’s User-Agent”

Common Use Cases & Example Commands

  • Create New Profile:
    “Create a new browser profile with Windows 10, latest Chrome, located in Los Angeles, using a SOCKS5 proxy.”

  • Update Fingerprint:
    “Modify the current profile’s Canvas and WebGL fingerprints to match a real device more closely.”

  • Batch Operations:
    “Create 10 different fingerprint profiles and assign unique proxies to each.”

  • Session Management:
    “Save cookies from the current browser session and restore them on next launch.”

Important Notes & Best Practices

  1. Network & Ports

    • Default port is 30897. Ensure your firewall allows traffic on this port.

    • Use the local address http://127.0.0.1:30897/mcp for security.

  2. Token Security

    • Keep your AUTH_TOKEN confidential.

    • Regenerate and update the token if it expires or becomes invalid.

  3. Compatibility

    • When switching AI tools (e.g., from Claude to Cursor), re-apply the configuration.

    • Reconfigure MCP whenever request headers change.

  4. Performance Tips

    • Initial connection may take a few seconds.

    • For large batch profile operations, process in smaller groups to avoid high resource usage.

  5. Troubleshooting

    • Connection Failed: Verify MostLogin is running, the port is not occupied, and the token is correct.

    • Commands Not Working: Ensure instructions explicitly mention “MostLogin” or “MCP” and clearly describe the desired action.

    • Proxy Issues: Confirm the proxy is working and specify the correct type (HTTP/SOCKS5) when creating profiles.

    • Check Logs: Use the MCP Server logs in the MostLogin interface for detailed diagnostics.