Devin

Devin Desktop and the Devin CLI

Devin Desktop was formerly Windsurf. Its default agent, Devin Local, reads MCP servers from the Devin CLI’s configuration, so one setup covers both.

Add WeHarness with the CLI

devin mcp add -s user weharness https://mcp.weharness.io/mcp

-s user makes WeHarness available in all your projects. Without it, the server is saved for the current folder only (.devin/mcp_config.local.json); -s project shares it through .devin/mcp_config.json.

Or edit the configuration file

The user configuration is ~/.config/devin/mcp_config.json on macOS and Linux ($XDG_CONFIG_HOME/devin/mcp_config.json when that variable is set), and %APPDATA%\devin\mcp_config.json on Windows:

{
  "mcpServers": {
    "weharness": {
      "url": "https://mcp.weharness.io/mcp",
      "transport": "http"
    }
  }
}

devin mcp login weharness

Your browser opens WeHarness sign-in. Sign in and allow the access Devin asks for. devin mcp logout weharness removes the stored sign-in from Devin.

The legacy Cascade agent

Devin Desktop’s legacy Cascade agent reads the same mcp_config.json but names the address serverUrl:

{
  "mcpServers": {
    "weharness": {
      "serverUrl": "https://mcp.weharness.io/mcp"
    }
  }
}

Open it from the Cascade panel: the … menu, then Open MCP config file in the MCPs section. The same section turns each server on or off.

The Devin web app

In Devin: Customize → MCPs → Add MCP → Add custom MCP → HTTP. Enter the URL https://mcp.weharness.io/mcp, choose OAuth as the auth method and Personal access, save, then select Connect and sign in.

Check the connection

Ask Devin:

List my WeHarness workspaces.

In the WeHarness app, Connect MCP now lists Devin with when it was last used. Devin stays signed in while you use it, for up to 90 days. See Sign-in and disconnect.

Removing WeHarness from Devin does not end its sign-in with WeHarness. To stop it at once, select Disconnect beside it in Connect MCP.