Web search: SearXNG `language` is hardcoded to `all` — could it be configurable?

[jborst-graetz]

Hi! 👋 First off, thank you for @librechat/agents — the web-search + scrape + rerank tooling is genuinely lovely to self-host, and the SearXNG integration has been great to work with. 🙏

I ran into one small thing while self-hosting and wanted to raise it gently, in case it's useful for others too.

What I noticed

The SearXNG search payload hardcodes the language to all:

// src/tools/search/search.ts (~L293)
const params: t.SearxNGSearchPayload = {
  q: query,
  format: 'json',
  pageno: 1,
  categories: category,
  language: 'all',        // <-- always "all"
  safesearch: safeSearch,
  engines: 'google,bing,duckduckgo',
};

Why it's a little tricky for self-hosters

When language=all is sent, SearXNG ignores its own search.default_lang and lets the engines geolocate by the server's IP. So if the instance is hosted outside the user's country, results come back in the wrong region's language.

Concretely: our instance runs in Azure westeurope (Amsterdam, NL), and German queries (e.g. "beste Pizzeria <German town>") return Dutch / North-Holland results. Because the value is hardcoded, there's no way to influence it from LibreChat config or from SearXNG's default_lang — the all always wins. (Confirmed by diffing &language=all vs &language=de-DE against the same SearXNG instance.)

Would a small knob be welcome?

Any of these would fully solve it, in rough order of effort — very happy to defer to whatever fits the design best:

1. A config option, e.g. webSearch.searxngLanguage (or a generic searchLanguage), passed straight through to the payload.
2. Respect the user's LibreChat locale (the UI language) as the search language.
3. Simplest of all: only set language when a value is provided, so an unset language lets SearXNG's own default_lang take effect.

For now I'm working around it with a tiny reverse-proxy that rewrites the language query arg before it reaches SearXNG — works fine, but a first-class option would be much nicer and would help anyone self-hosting outside the US/their target region.

Happy to open a PR for option 1 or 3 if that'd be helpful — just let me know what you'd prefer. Thanks again for the great project! 🙏

Version: @librechat/agents@3.2.46.