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MCP tunnels quickstart

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

This quickstart takes you from zero to Claude calling a private MCP server through a tunnel. It uses Docker Compose with manual credential provisioning, 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 two-container tunnel stack (the proxy and cloudflared) plus a sample MCP server running alongside it. When everything is 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

  1. 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 manual credential provisioning.

    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)
  2. Set up the deployment directory

    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
  3. Generate a CA and server certificate

    The proxy terminates inner TLS using a certificate signed by a CA you control. Generate both:

    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

    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.

  4. Write the sample MCP server

    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
  5. Write the proxy config and compose file

    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:efb27b299d627e4134815663cb8896641eeaee025d734c0f695582b4df38f013
        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
  6. Start it

    docker compose up -d
    docker compose logs mcp-proxy | grep "route configured"
    docker compose logs cloudflared | grep "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.

  7. Call it from Claude

    In the Console, go to Managed Agents > Sessions and create a session. In the agent picker choose Create new agent, give the agent a name, and keep the pre-filled model. 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. To swap in your own MCP server, add it to docker-compose.yaml (or run it on the same Docker network), add a route for it in config/mcp-proxy.yaml, then restart the proxy (docker compose restart mcp-proxy).

For production deployments:

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

Kubernetes deployment with automatic credential management.

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