sing-box/docs/configuration/outbound/vmess.md

Structure

{
  "outbounds": [
    {
      "type": "vmess",
      "tag": "vmess-out",
      
      "server": "127.0.0.1",
      "server_port": 1080,
      "uuid": "bf000d23-0752-40b4-affe-68f7707a9661",
      "security": "auto",
      "alter_id": 0,
      "global_padding": false,
      "authenticated_length": true,
      "network": "tcp",
      "tls": {},
      "multiplex": {},

      "detour": "upstream-out",
      "bind_interface": "en0",
      "routing_mark": 1234,
      "reuse_addr": false,
      "connect_timeout": "5s",
      "tcp_fast_open": false,
      "domain_strategy": "prefer_ipv6",
      "fallback_delay": "300ms"
    }
  ]
}

VMess Fields

server

==Required==

The server address.

server_port

==Required==

The server port.

uuid

==Required==

The VMess user id.

security

Encryption methods:

• auto
• none
• zero
• aes-128-gcm
• chancha20-poly1305

Legacy encryption methods:

• aes-128-ctr

alter_id

Alter ID	Description
0	Use AEAD protocol
1	Use legacy protocol
> 1	Unused, same as 1

global_padding

Protocol parameter. Will waste traffic randomly if enabled (enabled by default in v2ray and cannot be disabled).

authenticated_length

Protocol parameter. Enable length block encryption.

network

Enabled network

One of tcp udp.

Both is enabled by default.

tls

TLS configuration, see TLS outbound structure.

multiplex

Multiplex configuration, see Multiplex structure.

Dial Fields

detour

The tag of the upstream outbound.

Other dial fields will be ignored when enabled.

bind_interface

The network interface to bind to.

routing_mark

!!! error ""

Linux only

The iptables routing mark.

reuse_addr

Reuse listener address.

connect_timeout

Connect timeout, in golang's Duration format.

A duration string is a possibly signed sequence of decimal numbers, each with optional fraction and a unit suffix, such as "300ms", "-1.5h" or "2h45m". Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".

domain_strategy

One of prefer_ipv4 prefer_ipv6 ipv4_only ipv6_only.

If set, the server domain name will be resolved to IP before connecting.

dns.strategy will be used if empty.

fallback_delay

The length of time to wait before spawning a RFC 6555 Fast Fallback connection. That is, is the amount of time to wait for IPv6 to succeed before assuming that IPv6 is misconfigured and falling back to IPv4 if prefer_ipv4 is set. If zero, a default delay of 300ms is used.

Only take effect when domain_strategy is prefer_ipv4 or prefer_ipv6.