> ## Documentation Index
> Fetch the complete documentation index at: https://sunpeak.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# sunpeak inspect

> Inspect any MCP server in the inspector.

## Overview

The `sunpeak inspect` command connects to any MCP server and launches the inspector — no sunpeak project required. Use it to test and debug MCP servers built with any language or framework.

```bash theme={null}
sunpeak inspect --server <url-or-command>
```

## Options

| Option                   | Short | Description                                           |
| ------------------------ | ----- | ----------------------------------------------------- |
| `--server <url\|cmd>`    | `-s`  | MCP server URL (HTTP/SSE) or stdio command (required) |
| `--simulations <dir>`    |       | Directory of simulation JSON fixtures (optional)      |
| `--port <number>`        | `-p`  | Inspector port (default: 3000)                        |
| `--name <string>`        |       | App name displayed in inspector chrome                |
| `--env <KEY=VALUE>`      |       | Environment variable for stdio servers (repeatable)   |
| `--cwd <path>`           |       | Working directory for stdio servers                   |
| `--header <Name: value>` | `-H`  | HTTP header for HTTP MCP servers (repeatable)         |

## Examples

```bash theme={null}
# Connect to an HTTP MCP server
sunpeak inspect --server http://localhost:8000/mcp

# Pass an Authorization header to an HTTP MCP server
sunpeak inspect --server http://localhost:8000/mcp -H "Authorization: Bearer $TOKEN"

# Connect to a stdio MCP server
sunpeak inspect --server "python my_server.py"

# Pass env vars and a working directory to a stdio server
sunpeak inspect --server "python server.py" --env API_KEY=sk-123 --cwd ./backend

# With simulation fixtures for mock data
sunpeak inspect --server http://localhost:8000/mcp --simulations tests/simulations
```

## How It Works

1. Connects to the MCP server via HTTP/SSE or stdio transport
2. Discovers tools and resources via MCP protocol (`tools/list`, `resources/list`)
3. Builds simulations from discovered tools, optionally merging JSON fixtures from `--simulations`
4. Launches the multi-host inspector UI (Vite dev server)
5. Proxies tool calls and resource reads through to the connected server

## Transport Support

* **HTTP/SSE**: URLs starting with `http://` or `https://` connect via Streamable HTTP transport
* **Stdio**: Any other string is parsed as a shell command and connects via stdio transport (e.g., `"python my_server.py"`, `"node server.js"`)

## Authentication

sunpeak auto-negotiates MCP OAuth when the server returns 401 Unauthorized and publishes standard MCP OAuth metadata. If you already have a token, pass it as an HTTP header:

```bash theme={null}
sunpeak inspect --server http://localhost:8000/mcp -H "Authorization: Bearer $TOKEN"
```

You can repeat `--header` for other HTTP auth schemes or tenant headers.

## Combining with Simulations

Use `--simulations` to overlay mock data on discovered tools. This lets you test specific states without modifying your server:

```bash theme={null}
sunpeak inspect --server http://localhost:8000/mcp --simulations ./fixtures
```

Simulation JSON files in the directory are matched to tools by filename. See [Simulation API Reference](/testing/simulations) for the JSON schema.

## Related Commands

<CardGroup cols={2}>
  <Card horizontal title="sunpeak dev" icon="code" href="/app-framework/cli/dev">
    Full dev server with built-in inspector for sunpeak projects.
  </Card>

  <Card horizontal title="Inspector" icon="desktop" href="/mcp-apps-inspector">
    Inspector concepts and features.
  </Card>
</CardGroup>