Give Devin Local a browser that survives the task.

Authentication disabled

Devin CLI

devin mcp add -s user hronaut http://127.0.0.1:47812/mcp

A URL selects Streamable HTTP automatically. This command intentionally contains no bearer token.

Equivalent user configuration

~/.config/devin/mcp_config.json

{
  "mcpServers": {
    "hronaut": {
      "url": "http://127.0.0.1:47812/mcp",
      "transport": "http"
    }
  }
}

Authentication enabled

Read the owner token from its file

Enable Require MCP authentication in Hronaut, then copy the current token-file path from Hronaut Home into this user-only configuration. Devin supports file interpolation, so the token does not need to appear in JSON.

{
  "mcpServers": {
    "hronaut": {
      "url": "http://127.0.0.1:47812/mcp",
      "transport": "http",
      "headers": {
        "Authorization": "Bearer ${file:/path/from-hronaut-home}"
      }
    }
  }
}

Do not commit the resolved token, paste it into chat, or copy it into a project-scoped .devin/mcp_config.json.

3 · Browser task

Create an isolated workspace

Ask: “Create a Hronaut workspace named first-check, open https://example.com inside it, and tell me the page title and workspace ID. Do not use my Default workspace.”

Expect a visible first-check workspace showing Example Domain.

Legacy Cascade

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "hronaut": {
      "serverUrl": "http://127.0.0.1:47812/mcp"
    }
  }
}

Cascade also documents ${file:/path} interpolation for protected headers. See the official legacy Cascade MCP guide ↗.