NousResearch/hermes-agent · error · GeminiAPIError

gemini_stream_error

gemini_stream_error

Error message

Gemini streaming request failed: {exc}

What it means

The streaming Gemini request (streamGenerateContent?alt=sse) failed with an httpx.HTTPError — connection error, timeout, or protocol-level failure during the SSE stream — before or while yielding chunks. It is wrapped in GeminiAPIError with code 'gemini_stream_error'. HTTP-status errors inside the stream are handled separately (gemini_http_error), so this code specifically means transport failure.

Source

Thrown at agent/gemini_native_adapter.py:1088

        return translate_gemini_response(payload, model=model)

    def _stream_completion(self, *, model: str, request: Dict[str, Any], timeout: Any = None) -> Iterator[_GeminiStreamChunk]:
        url = f"{self.base_url}/models/{model}:streamGenerateContent?alt=sse"
        stream_headers = dict(self._headers())
        stream_headers["Accept"] = "text/event-stream"

        def _generator() -> Iterator[_GeminiStreamChunk]:
            try:
                with self._http.stream("POST", url, json=request, headers=stream_headers, timeout=timeout) as response:
                    if response.status_code != 200:
                        body_text = read_streaming_error_body(response)
                        raise gemini_http_error(response, body_text=body_text)
                    tool_call_indices: Dict[str, Dict[str, Any]] = {}
                    for event in _iter_sse_events(response):
                        for chunk in translate_stream_event(event, model, tool_call_indices):
                            yield chunk
            except httpx.HTTPError as exc:
                raise GeminiAPIError(
                    f"Gemini streaming request failed: {exc}",
                    code="gemini_stream_error",
                ) from exc

        return _generator()


class AsyncGeminiNativeClient:
    """Async wrapper used by auxiliary_client for native Gemini calls."""

    def __init__(self, sync_client: GeminiNativeClient):
        self._sync = sync_client
        self.api_key = sync_client.api_key
        self.base_url = sync_client.base_url
        self.chat = _AsyncGeminiChatNamespace(self)
        # Expose the underlying sync client as _real_client so the auxiliary
        # cache's eviction-by-leaf-client helper (#23482) can find and drop
        # this async entry when the sync GeminiNativeClient is poisoned.

View on GitHub (pinned to c896c09c42)

Solutions

1. Retry the request — transient resets during long streams are common and usually succeed on retry.
2. Increase the client timeout passed to the adapter if failures cluster at a consistent elapsed time (timeout too small).
3. Check network stability (VPN/proxy) if streams consistently die mid-generation.
4. If persistent, capture the underlying httpx error message to distinguish connect vs read failures.

Example fix

# caller-side retry for transient stream transport errors
from agent.gemini_native_adapter import GeminiAPIError

for attempt in range(3):
    try:
        chunks = list(client.chat.completions.create(model=m, messages=msgs, stream=True))
        break
    except GeminiAPIError as e:
        if e.code != "gemini_stream_error" or attempt == 2:
            raise

from agent.gemini_native_adapter import GeminiAPIError

for attempt in range(3):
    try:
        chunks = list(client.chat.completions.create(model=m, messages=msgs, stream=True))
        break
    except GeminiAPIError as e:
        if e.code != 'gemini_stream_error' or attempt == 2:
            raise

When it happens

Trigger: Any httpx.HTTPError raised inside the stream generator: DNS/connect failure, connection reset mid-stream, read timeout while waiting for SSE events, TLS errors.

Common situations: Flaky network or VPN drops during long streaming generations; Google API transient resets; local firewall killing long-lived SSE connections; timeout configured too aggressively for slow generations.

Related errors

• Gateway did not return a WS ticket.
• Reached the gateway over HTTP, but the live WebSocket (/api/
• Extension "${id}" was not found on the Marketplace.
• Could not fetch image: ${response.status}
• Could not refresh the remote gateway WebSocket ticket.

AI-assisted analysis of NousResearch/hermes-agent@c896c09c42 (2026-08-14). Data as JSON: /api/errors/f428bd143d4f180e. Report an issue: GitHub.