**Feature Request: Add UDP and TCP proxy support alongside existing HTTP/HTTPS**

[nglmercer]

Problem

Description

Slim currently only supports HTTP/HTTPS protocols with WebSocket support. This feature request aims to extend Slim's capabilities to include generic TCP and UDP proxying, making it a more versatile local development tool.

Current State

Slim is designed as an HTTP/HTTPS reverse proxy for local development . It supports:

• HTTP/HTTPS with automatic redirects
• HTTP/2.
• WebSocket via HTTP upgrade
• TCP as underlying transport only

Technical Considerations

• Architecture: Need to extend proxy.Server struct to handle TCP/UDP listeners
• Port Forwarding: Current iptables/pfctl rules only handle TCP
• Certificate Management: TLS certificates not needed for raw TCP/UDP
• Logging: Extend access logging for TCP/UDP connections

Use Cases

• Database proxying (MySQL, PostgreSQL on TCP)
• DNS server development (UDP)
• Game server development (UDP)
• Microservices with non-HTTP protocols

Proposed Solution

1. TCP Proxy Support

• Add TCP listener alongside existing HTTP servers
• Implement raw TCP connection forwarding
• Extend configuration to support TCP routes
• Modify port forwarding rules to handle arbitrary TCP ports

2. UDP Proxy Support

• Add UDP packet forwarding capabilities
• Implement UDP connection tracking for stateless proxying
• Handle UDP-specific challenges (connection tracking, timeouts)

3. Configuration Extension

Extend .slim.yaml to support:

domains:
  - domain: myapp
    port: 3000
    tcp_routes:
      - port: 3306
        target: localhost:3307
    udp_routes:
      - port: 53
        target: localhost:8053

Alternatives Considered

No response

[HarshBhanushali07]

How should TCP routes integrate with current proxy.Server?