sing-box/docs/configuration/inbound/direct.md

direct inbound is a tunnel server.

Structure

{
  "inbounds": [
    {
      "type": "direct",
      "tag": "direct-in",
      
      "listen": "::",
      "listen_port": 5353,
      "tcp_fast_open": false,
      "sniff": false,
      "sniff_override_destination": false,
      "domain_strategy": "prefer_ipv6",
      "udp_timeout": 300,
      
      "network": "udp",
      "override_address": "1.0.0.1",
      "override_port": 53
    }
  ]
}

Listen Fields

listen

Listen address.

listen_port

Listen port.

tcp_fast_open

Enable tcp fast open for listener.

sniff

Enable sniffing.

Reads domain names for routing, supports HTTP TLS for TCP, QUIC for UDP.

This does not break zero copy, like splice.

sniff_override_destination

Override the connection destination address with the sniffed domain.

If the domain name is invalid (like tor), this will not work.

domain_strategy

One of prefer_ipv4 prefer_ipv6 ipv4_only ipv6_only.

If set, the requested domain name will be resolved to IP before routing.

If sniff_override_destination is in effect, its value will be taken as a fallback.

udp_timeout

UDP NAT expiration time in seconds, default is 300 (5 minutes).

Direct Fields

network

Listen network, one of tcp udp.

Both if empty.

override_address

Override the connection destination address.

override_port

Override the connection destination port.