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MCP tunnels quickstart ​

Connect Claude to a private MCP server using a local Docker Compose deployment.


INFO

MCP tunnels is a research preview feature. Request access to try it.

This quickstart takes you from zero to Claude calling a private MCP server through a tunnel. It uses Docker Compose with manually supplied credentials, which is the shortest path for local testing. For production deployments, see Deploy with Helm or Deploy with Docker Compose.

What you'll build ​

A three-container stack on your machine: a sample MCP server, the tunnel proxy, and the outbound connector. When it's running, the sample server is reachable from Claude at https://echo.<your-tunnel-domain>/mcp even though nothing is listening on a public port.

What you need ​

  • Docker and Docker Compose on a machine with outbound internet access.
  • A role in the Claude Console that can manage MCP tunnels. See the Console guide prerequisites.
  • OpenSSL 1.1.1 or later. Preinstalled on macOS and most Linux distributions; on Windows, install it separately (the openssl binary must be on your PATH).

Create a tunnel ​

In the Claude Console sidebar, go to **Manage > MCP tunnels** and click **New tunnel**. Give it a name. Leave **Set up programmatic access** off; this quickstart uses manually supplied credentials.

After it's created, open the tunnel. Copy two values from the **Connection** section:

- **Domain** (looks like `abcd1234.tunnel.anthropic.com`)
- **Token** (click the eye icon, then copy)

Set up the deployment directory ​

bash
```bash
    mkdir -p mcp-tunnel/{config,data}
    cd mcp-tunnel
    export TUNNEL_DOMAIN=YOUR_TUNNEL_DOMAIN_HERE   # from step 1
    export TUNNEL_TOKEN='eyJ...'            # from step 1
    ```
powershell
```powershell
    New-Item -ItemType Directory -Force -Path mcp-tunnel/config, mcp-tunnel/data | Out-Null
    Set-Location mcp-tunnel
    $env:TUNNEL_DOMAIN = "YOUR_TUNNEL_DOMAIN_HERE"   # from step 1
    $env:TUNNEL_TOKEN  = "eyJ..."             # from step 1
    ```

Generate a CA and server certificate ​

The proxy terminates an inner TLS handshake using a certificate signed by a CA you control. Generate both:
bash
```bash
    openssl req -x509 -newkey rsa:2048 -nodes \
      -keyout data/ca.key -out data/ca.crt \
      -days 3650 -subj "/CN=mcp-tunnel-ca" \
      -addext "basicConstraints=critical,CA:TRUE" \
      -addext "keyUsage=critical,keyCertSign,cRLSign" \
      -addext "subjectKeyIdentifier=hash"

    cat > data/tls.ext <<EOF
    subjectAltName = DNS:${TUNNEL_DOMAIN},DNS:*.${TUNNEL_DOMAIN}
    authorityKeyIdentifier = keyid,issuer
    extendedKeyUsage = serverAuth
    EOF

    openssl req -newkey rsa:2048 -nodes \
      -keyout data/tls.key -out /tmp/server.csr \
      -subj "/CN=${TUNNEL_DOMAIN}"
    openssl x509 -req -in /tmp/server.csr \
      -CA data/ca.crt -CAkey data/ca.key -CAcreateserial \
      -out data/tls.crt -days 90 -extfile data/tls.ext

    chmod 644 data/tls.key
    ```
powershell
```powershell
    openssl req -x509 -newkey rsa:2048 -nodes `
      -keyout data/ca.key -out data/ca.crt `
      -days 3650 -subj "/CN=mcp-tunnel-ca" `
      -addext "basicConstraints=critical,CA:TRUE" `
      -addext "keyUsage=critical,keyCertSign,cRLSign" `
      -addext "subjectKeyIdentifier=hash"

    @"
    subjectAltName = DNS:$env:TUNNEL_DOMAIN,DNS:*.$env:TUNNEL_DOMAIN
    authorityKeyIdentifier = keyid,issuer
    extendedKeyUsage = serverAuth
    "@ | Set-Content -NoNewline -Encoding ascii -Path data/tls.ext

    openssl req -newkey rsa:2048 -nodes `
      -keyout data/tls.key -out data/server.csr `
      -subj "/CN=$env:TUNNEL_DOMAIN"
    openssl x509 -req -in data/server.csr `
      -CA data/ca.crt -CAkey data/ca.key -CAcreateserial `
      -out data/tls.crt -days 90 -extfile data/tls.ext
    ```
Back in the Console, on the tunnel detail page, click **Add certificate** and upload `data/ca.crt` (or paste its contents). The tunnel status flips to **Active**.

Write the sample MCP server ​

bash
```bash
    cat > hello_server.py <<'EOF'
    from mcp.server.fastmcp import FastMCP

    mcp = FastMCP("hello-server", host="0.0.0.0", port=9000)


    @mcp.tool()
    def hello(name: str = "world") -> str:
        """Say hello to someone."""
        return f"Hello, {name}!"


    if __name__ == "__main__":
        mcp.run(transport="streamable-http")
    EOF
    ```
powershell
```powershell
    @'
    from mcp.server.fastmcp import FastMCP

    mcp = FastMCP("hello-server", host="0.0.0.0", port=9000)


    @mcp.tool()
    def hello(name: str = "world") -> str:
        """Say hello to someone."""
        return f"Hello, {name}!"


    if __name__ == "__main__":
        mcp.run(transport="streamable-http")
    '@ | Set-Content -NoNewline -Encoding ascii -Path hello_server.py
    ```

Write the proxy config and compose file ​

bash
```bash
    cat > config/mcp-proxy.yaml <<EOF
    listen_addr: ":8080"
    tunnel_domain: ${TUNNEL_DOMAIN}
    tls:
      cert_file: /data/tls.crt
      key_file: /data/tls.key
    routes:
      echo: http://hello-mcp:9000
    EOF

    cat > docker-compose.yaml <<'EOF'
    services:
      mcp-proxy:
        image: us-docker.pkg.dev/anthropic-public-registry/images/mcp-proxy@sha256:6b9adedbf2763143ec72f106ecaf0ce7fd3294e89b208f54a1db97a33d14c5ba
        volumes:
          - ./config/mcp-proxy.yaml:/etc/mcp-gateway/config.yaml:ro
          - ./data:/data:ro
        restart: unless-stopped

      cloudflared:
        image: cloudflare/cloudflared@sha256:6b599ca3e974349ead3286d178da61d291961182ec3fe9c505e1dd02c8ac31b0
        command: tunnel --no-autoupdate run --url http://localhost:8080
        environment:
          - TUNNEL_TOKEN
        network_mode: "service:mcp-proxy"
        restart: unless-stopped

      hello-mcp:
        image: python:3.13-slim
        working_dir: /app
        volumes:
          - ./hello_server.py:/app/hello_server.py:ro
        command: sh -c "pip install --quiet mcp && python hello_server.py"
        restart: unless-stopped
    EOF
    ```
powershell
```powershell
    @"
    listen_addr: ":8080"
    tunnel_domain: $env:TUNNEL_DOMAIN
    tls:
      cert_file: /data/tls.crt
      key_file: /data/tls.key
    routes:
      echo: http://hello-mcp:9000
    "@ | Set-Content -NoNewline -Encoding ascii -Path config/mcp-proxy.yaml

    @'
    services:
      mcp-proxy:
        image: us-docker.pkg.dev/anthropic-public-registry/images/mcp-proxy@sha256:6b9adedbf2763143ec72f106ecaf0ce7fd3294e89b208f54a1db97a33d14c5ba
        volumes:
          - ./config/mcp-proxy.yaml:/etc/mcp-gateway/config.yaml:ro
          - ./data:/data:ro
        restart: unless-stopped

      cloudflared:
        image: cloudflare/cloudflared@sha256:6b599ca3e974349ead3286d178da61d291961182ec3fe9c505e1dd02c8ac31b0
        command: tunnel --no-autoupdate run --url http://localhost:8080
        environment:
          - TUNNEL_TOKEN
        network_mode: "service:mcp-proxy"
        restart: unless-stopped

      hello-mcp:
        image: python:3.13-slim
        working_dir: /app
        volumes:
          - ./hello_server.py:/app/hello_server.py:ro
        command: sh -c "pip install --quiet mcp && python hello_server.py"
        restart: unless-stopped
    '@ | Set-Content -NoNewline -Encoding ascii -Path docker-compose.yaml
    ```

Start it ​

bash
```bash
    docker compose up -d
    docker compose logs mcp-proxy | grep "route configured"
    docker compose logs cloudflared | grep "Registered tunnel connection"
    ```
powershell
```powershell
    docker compose up -d
    docker compose logs mcp-proxy | Select-String "route configured"
    docker compose logs cloudflared | Select-String "Registered tunnel connection"
    ```
You should see one `route configured` line for `echo` and four `Registered tunnel connection` lines. The containers take a few seconds to start; rerun the log commands if they come back empty.

Call it from Claude ​

In the Console, go to **Managed Agents > Sessions** and create a session. In the agent picker choose **Create new agent**, then click **+ MCP Server**, select your tunnel, set **Subdomain** to `echo` and **Path** to `mcp`. Then ask:

> Use the hello tool to greet tunnel.

You should see a tool call followed by its result.

Next steps ​

The tunnel is verified end to end. For production deployments:

Hardened single-host deployment, with or without programmatic access.


Kubernetes deployment with automatic credential management.