---
title: "Running the Server"
description: "How to run your mcp-use server with different transport methods"
icon: "play"
---
<Info>
Learn how to run your mcp-use server using different transport methods and configurations.
</Info>

## Basic Usage

```python
from mcp_use.server import MCPServer

server = MCPServer(name="My Server")

# Run with stdio transport (for MCP clients)
server.run(transport="stdio")

# Run with HTTP transport (for web clients)
server.run(transport="streamable-http")
```

## Transport Methods

### stdio Transport

Standard input/output transport for MCP clients:

```python
server.run(transport="stdio")
```

### streamable-http Transport

HTTP-based transport for web clients:

```python
server.run(
    transport="streamable-http",
    host="0.0.0.0",
    port=8000,
    reload=False,
    debug=False
)
```

## Host and Port Configuration

You can configure host and port either at initialization or when calling `run()`.
Values passed to `run()` override those set in `__init__()`, and DNS rebinding
protection is automatically reconfigured to match:

```python
# Set defaults at initialization
server = MCPServer(name="My Server", host="0.0.0.0", port=3000)
server.run()  # Uses host="0.0.0.0", port=3000, no DNS protection

# Override at runtime - DNS protection is reconfigured automatically
server.run(host="127.0.0.1", port=8080)  # Switches to localhost with DNS protection
```

### Default Values

| Parameter | Default | Description |
|-----------|---------|-------------|
| `host` | `"0.0.0.0"` | Bind address. Use `"127.0.0.1"` for local-only access |
| `port` | `8000` | Port number |

## Automatic Port Retry

When the requested port is already in use (e.g., another server is running on port 8000), the server automatically tries the next available port instead of crashing:

```
Port 8000 is in use, using port 8001 instead.

- Local:        http://0.0.0.0:8001
- MCP:          http://0.0.0.0:8001/mcp
```

The server tries up to 10 consecutive ports (8000, 8001, ..., 8009). If none are available, it raises an error. This makes it easy to run multiple MCP servers simultaneously during development without manually specifying different ports.

<Tip>
The startup output always shows the actual port the server bound to, so you'll know where to connect.
</Tip>

## Cloud and Proxy Deployments

When deploying behind reverse proxies (Cloudflare, nginx, Fly.io, etc.), the server
automatically configures DNS rebinding protection based on the host:

- **`host="0.0.0.0"`** (default): DNS rebinding protection is **disabled**, allowing
  any Host header. This is safe when your proxy handles host validation.

- **`host="127.0.0.1"`**: DNS rebinding protection is **enabled**, only allowing
  requests with `Host: 127.0.0.1:*` or `Host: localhost:*`.

```python
# Cloud deployment (behind proxy) - default, no DNS protection
server = MCPServer(name="My Server")
server.run(transport="streamable-http")

# Local development - auto-enables DNS protection
server = MCPServer(name="My Server", host="127.0.0.1")
server.run(transport="streamable-http")
```

<Warning>
If you get **421 Misdirected Request** errors behind a proxy, ensure you're using
`host="0.0.0.0"` (the default).
</Warning>

## Debug Mode

Enable debug mode for development features:

```python
server = MCPServer(name="My Server", debug=True)

# Debug mode enables:
# - /openmcp.json endpoint
# - /docs endpoint
# - /inspector endpoint
# - Enhanced logging
server.run(transport="streamable-http", debug=True)
```

## Auto-reload

Enable auto-reload during development:

```python
server.run(transport="streamable-http", reload=True)
```

## Production Configuration

```python
server = MCPServer(
    name="My Server",
    host="0.0.0.0",
    port=8000,
)

server.run(
    transport="streamable-http",
    reload=False,
    debug=False
)
```

## Command Line

Run directly with Python:

```bash
python my_server.py
```

Or use uvicorn directly:

```bash
uvicorn my_server:app --host 0.0.0.0 --port 8000
```
