sgl-project/sglang · error · ValueError

Unknown browser action: {recipient}

Error message

Unknown browser action: {recipient}

What it means

SGLang's browser tool dispatcher received a recipient starting with 'browser.' that is not one of the supported actions (browser.search, browser.open, browser.find). This indicates an unrecognized or misspelled browser action name.

Source

Thrown at python/sglang/srt/entrypoints/tool.py:87

        if recipient == "browser.search":
            query = args.get("query")
            if not query:
                raise ValueError("browser.search requires a query")
            data = await self.exa_client.search(query)
            return self._format_search_results(context, query, data)

        if recipient == "browser.open":
            url = self._resolve_url(context, args)
            data = await self.exa_client.contents([url])
            return self._format_page_contents(context, url, data)

        if recipient == "browser.find":
            pattern = args.get("pattern")
            if not pattern:
                raise ValueError("browser.find requires a pattern")
            return await self._find_pattern(context, args, pattern)

        raise ValueError(f"Unknown browser action: {recipient}")

    def _browser_state(self, context: "ConversationContext") -> dict[str, Any]:
        state = getattr(context, "_sglang_exa_browser_state", None)
        if state is None:
            state = {"pages": {}, "page_text": {}}
            setattr(context, "_sglang_exa_browser_state", state)
        return state

    def _format_search_results(
        self, context: "ConversationContext", query: str, data: dict[str, Any]
    ) -> str:
        state = self._browser_state(context)
        state["pages"] = {}
        state["page_text"] = {}

        results = data.get("results") or []
        request_id = data.get("requestId")
        if request_id:

View on GitHub (pinned to 0132848349)

Solutions

1. Check the exact recipient string against the supported set: browser.search/browser.open/browser.find
2. Upgrade SGLang if a newer browser action is required and supported in a later release
3. Re-prompt the model to use one of the supported actions

Example fix

# before
recipient = "browser.navigate"
# after
recipient = "browser.open"  # with {"url": "..."}

SUPPORTED = {"browser.search", "browser.open", "browser.find"}
recipient = last_msg.recipient
assert recipient in SUPPORTED, f"unsupported browser action: {recipient}"

def is_supported_browser_action(recipient: str) -> bool:
    return recipient in {"browser.search", "browser.open", "browser.find"}

try:
    out = await tool._dispatch_browser_call(context, recipient, args)
except ValueError as e:
    if str(e).startswith("Unknown browser action"):
        out = await tool._dispatch_browser_call(context, "browser.search", {"query": str(args)})

When it happens

Trigger: Dispatching e.g. 'browser.navigate', 'browser.click', or 'browser.Search' (wrong case) through get_result or run_tool_flow.

Common situations: Model hallucinating an unlisted browser action, a typo in a manually crafted tool call, or newer model tool schemas advertising actions this SGLang version does not implement (version mismatch after upgrade).

Related errors

• No browser tool call found
• browser.search requires a query
• browser.find requires a pattern
• browser.open requires a cursor or url
• Unknown browser cursor: {cursor}

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/92a240b48c8bfa96. Report an issue: GitHub.