Missing Host header in s-ui generated Clash sub causes external WS nodes to timeout in Mihomo

[L3105180447]

Description

When importing external WS nodes (e.g., VLESS) containing a host or sni parameter into the s-ui panel, the generated Clash subscription YAML is missing the headers: Host field under ws-opts.

This causes WebSocket handshake failures (usually HTTP 400 Bad Request) and node timeouts when testing the subscription in the Mihomo (Clash Meta) core, especially when the node is behind a strict CDN or reverse proxy (like Nginx).

Config Comparison

❌ Current generated config (Missing Headers):

    network: ws
    servername: bbb.example.com
    ws-opts:
      path: /yourpath?ed=2560
      # Missing headers field here

Expected generated config:
    network: ws
    servername: bbb.example.com
    ws-opts:
      path: /yourpath?ed=2560
      headers:
        Host: bbb.example.com  # ⬅️ Expect s-ui to auto-fill this based on SNI/Host

[alireza0]

Confirmed and fixed. There were actually two problems in the Clash/Mihomo converter:

The Host header was never emitted at all. sing-box stores WS headers as a map (headers: { Host: ... }), but the converter was reading them as an array, so the type check always failed and the headers got dropped silently.
No fallback when Host is absent. Now, if there's no explicit WS Host, the converter fills ws-opts.headers.Host from the node's host (httpupgrade) or, failing that, from the TLS SNI — which is exactly the auto-fill you asked for.
Resulting YAML now contains:

ws-opts:
  path: /yourpath?ed=2560
  headers:
    Host: bbb.example.com

This applies to both ws and httpupgrade transports.

Will be in the next release
Thanks for the clear comparison, it made the root cause obvious.