# Feedthrough MCP server

> Injects a debug bridge into web applications to let AI agents inspect the DOM, console logs, and network requests in real time.

- Repository: https://github.com/feedthrough/feedthrough
- Page: https://hostedmcp.org/servers/feedthrough/feedthrough
- Transport: stdio
- Stars: 4
- License: MIT
- Latest version: 0.4.0

## Install

### Claude Code

```sh
claude mcp add feedthrough -- npx -y @feedthrough/mcp
```

### Cursor (`~/.cursor/mcp.json`)

```json
{
  "mcpServers": {
    "feedthrough": {
      "command": "npx",
      "args": [
        "-y",
        "@feedthrough/mcp"
      ]
    }
  }
}
```

### VS Code (`.vscode/mcp.json`)

```json
{
  "servers": {
    "feedthrough": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@feedthrough/mcp"
      ]
    }
  }
}
```

### VS Code CLI

```sh
code --add-mcp '{"name":"feedthrough","type":"stdio","command":"npx","args":["-y","@feedthrough/mcp"]}'
```

### Claude Desktop (`claude_desktop_config.json`)

```json
{
  "mcpServers": {
    "feedthrough": {
      "command": "npx",
      "args": [
        "-y",
        "@feedthrough/mcp"
      ]
    }
  }
}
```

### Codex

```sh
codex mcp add feedthrough -- npx -y @feedthrough/mcp
```

### Codex config.toml (`~/.codex/config.toml`)

```toml
[mcp_servers.feedthrough]
command = "npx"
args = ["-y", "@feedthrough/mcp"]
```

### Gemini CLI

```sh
gemini mcp add -s user feedthrough npx -- -y @feedthrough/mcp
```

### Gemini settings.json (`~/.gemini/settings.json`)

```json
{
  "mcpServers": {
    "feedthrough": {
      "command": "npx",
      "args": [
        "-y",
        "@feedthrough/mcp"
      ]
    }
  }
}
```

## Environment variables

| Name | Required | Secret | Description |
|---|---|---|---|
| `FEEDTHROUGH_ALLOWED_HOST_SUFFIXES` | no | no | Comma-separated non-loopback host suffixes allowed to connect (defaults to .test). Setting it replaces the default, so include .test to keep it. |
| `FEEDTHROUGH_PORT` | no | no | Port the bridge WebSocket server listens on (defaults to 8765). |

## FAQ

### How does Feedthrough differ from other browser MCP tools?

Unlike external observers that use Puppeteer or CDP and only work in Chrome, Feedthrough is an embedded agent that runs inside the page, allowing it to see framework internals and work in any browser.

### Does changing styles or attributes with the AI agent save to my source code?

No, live edits are only previews in the running DOM and are not written to your source files; they reset on reload or HMR.

### What happens if the default port is already in use?

The server will automatically step up to the next available port (e.g., 8766, 8767) instead of failing to start.