feat(providers): route gemini through the native AI Studio API

- add a native Gemini adapter over generateContent/streamGenerateContent
- switch the built-in gemini provider off the OpenAI-compatible endpoint
- preserve thought signatures and native functionResponse replay
- route auxiliary Gemini clients through the same adapter
- add focused unit coverage plus native-provider integration checks
This commit is contained in:
kshitijk4poor 2026-04-20 00:00:50 +05:30 committed by Teknium
parent aa5bd09232
commit 3dea497b20
7 changed files with 1070 additions and 29 deletions

View file

@ -0,0 +1,796 @@
"""OpenAI-compatible facade over Google AI Studio's native Gemini API.
Hermes keeps ``api_mode='chat_completions'`` for the ``gemini`` provider so the
main agent loop can keep using its existing OpenAI-shaped message flow.
This adapter is the transport shim that converts those OpenAI-style
``messages[]`` / ``tools[]`` requests into Gemini's native
``models/{model}:generateContent`` schema and converts the responses back.
Why this exists
---------------
Google's OpenAI-compatible endpoint has been brittle for Hermes's multi-turn
agent/tool loop (auth churn, tool-call replay quirks, thought-signature
requirements). The native Gemini API is the canonical path and avoids the
OpenAI-compat layer entirely.
"""
from __future__ import annotations
import asyncio
import base64
import json
import logging
import time
import uuid
from types import SimpleNamespace
from typing import Any, Dict, Iterator, List, Optional
import httpx
logger = logging.getLogger(__name__)
DEFAULT_GEMINI_BASE_URL = "https://generativelanguage.googleapis.com/v1beta"
class GeminiAPIError(Exception):
"""Error shape compatible with Hermes retry/error classification."""
def __init__(
self,
message: str,
*,
code: str = "gemini_api_error",
status_code: Optional[int] = None,
response: Optional[httpx.Response] = None,
retry_after: Optional[float] = None,
details: Optional[Dict[str, Any]] = None,
) -> None:
super().__init__(message)
self.code = code
self.status_code = status_code
self.response = response
self.retry_after = retry_after
self.details = details or {}
def _coerce_content_to_text(content: Any) -> str:
if content is None:
return ""
if isinstance(content, str):
return content
if isinstance(content, list):
pieces: List[str] = []
for part in content:
if isinstance(part, str):
pieces.append(part)
elif isinstance(part, dict) and part.get("type") == "text":
text = part.get("text")
if isinstance(text, str):
pieces.append(text)
return "\n".join(pieces)
return str(content)
def _extract_multimodal_parts(content: Any) -> List[Dict[str, Any]]:
if not isinstance(content, list):
text = _coerce_content_to_text(content)
return [{"text": text}] if text else []
parts: List[Dict[str, Any]] = []
for item in content:
if isinstance(item, str):
parts.append({"text": item})
continue
if not isinstance(item, dict):
continue
ptype = item.get("type")
if ptype == "text":
text = item.get("text")
if isinstance(text, str) and text:
parts.append({"text": text})
elif ptype == "image_url":
url = ((item.get("image_url") or {}).get("url") or "")
if not isinstance(url, str) or not url.startswith("data:"):
continue
try:
header, encoded = url.split(",", 1)
mime = header.split(":", 1)[1].split(";", 1)[0]
raw = base64.b64decode(encoded)
except Exception:
continue
parts.append(
{
"inlineData": {
"mimeType": mime,
"data": base64.b64encode(raw).decode("ascii"),
}
}
)
return parts
def _tool_call_extra_signature(tool_call: Dict[str, Any]) -> Optional[str]:
extra = tool_call.get("extra_content") or {}
if not isinstance(extra, dict):
return None
google = extra.get("google") or extra.get("thought_signature")
if isinstance(google, dict):
sig = google.get("thought_signature") or google.get("thoughtSignature")
return str(sig) if isinstance(sig, str) and sig else None
if isinstance(google, str) and google:
return google
return None
def _translate_tool_call_to_gemini(tool_call: Dict[str, Any]) -> Dict[str, Any]:
fn = tool_call.get("function") or {}
args_raw = fn.get("arguments", "")
try:
args = json.loads(args_raw) if isinstance(args_raw, str) and args_raw else {}
except json.JSONDecodeError:
args = {"_raw": args_raw}
if not isinstance(args, dict):
args = {"_value": args}
part: Dict[str, Any] = {
"functionCall": {
"name": str(fn.get("name") or ""),
"args": args,
}
}
thought_signature = _tool_call_extra_signature(tool_call)
if thought_signature:
part["thoughtSignature"] = thought_signature
return part
def _translate_tool_result_to_gemini(
message: Dict[str, Any],
tool_name_by_call_id: Optional[Dict[str, str]] = None,
) -> Dict[str, Any]:
tool_name_by_call_id = tool_name_by_call_id or {}
tool_call_id = str(message.get("tool_call_id") or "")
name = str(
message.get("name")
or tool_name_by_call_id.get(tool_call_id)
or tool_call_id
or "tool"
)
content = _coerce_content_to_text(message.get("content"))
try:
parsed = json.loads(content) if content.strip().startswith(("{", "[")) else None
except json.JSONDecodeError:
parsed = None
response = parsed if isinstance(parsed, dict) else {"output": content}
return {
"functionResponse": {
"name": name,
"response": response,
}
}
def _build_gemini_contents(messages: List[Dict[str, Any]]) -> tuple[List[Dict[str, Any]], Optional[Dict[str, Any]]]:
system_text_parts: List[str] = []
contents: List[Dict[str, Any]] = []
tool_name_by_call_id: Dict[str, str] = {}
for msg in messages:
if not isinstance(msg, dict):
continue
role = str(msg.get("role") or "user")
if role == "system":
system_text_parts.append(_coerce_content_to_text(msg.get("content")))
continue
if role in {"tool", "function"}:
contents.append(
{
"role": "user",
"parts": [
_translate_tool_result_to_gemini(
msg,
tool_name_by_call_id=tool_name_by_call_id,
)
],
}
)
continue
gemini_role = "model" if role == "assistant" else "user"
parts: List[Dict[str, Any]] = []
content_parts = _extract_multimodal_parts(msg.get("content"))
parts.extend(content_parts)
tool_calls = msg.get("tool_calls") or []
if isinstance(tool_calls, list):
for tool_call in tool_calls:
if isinstance(tool_call, dict):
tool_call_id = str(tool_call.get("id") or tool_call.get("call_id") or "")
tool_name = str(((tool_call.get("function") or {}).get("name") or ""))
if tool_call_id and tool_name:
tool_name_by_call_id[tool_call_id] = tool_name
parts.append(_translate_tool_call_to_gemini(tool_call))
if parts:
contents.append({"role": gemini_role, "parts": parts})
system_instruction = None
joined_system = "\n".join(part for part in system_text_parts if part).strip()
if joined_system:
system_instruction = {"parts": [{"text": joined_system}]}
return contents, system_instruction
def _translate_tools_to_gemini(tools: Any) -> List[Dict[str, Any]]:
if not isinstance(tools, list):
return []
declarations: List[Dict[str, Any]] = []
for tool in tools:
if not isinstance(tool, dict):
continue
fn = tool.get("function") or {}
if not isinstance(fn, dict):
continue
name = fn.get("name")
if not isinstance(name, str) or not name:
continue
decl: Dict[str, Any] = {"name": name}
description = fn.get("description")
if isinstance(description, str) and description:
decl["description"] = description
parameters = fn.get("parameters")
if isinstance(parameters, dict):
decl["parameters"] = parameters
declarations.append(decl)
return [{"functionDeclarations": declarations}] if declarations else []
def _translate_tool_choice_to_gemini(tool_choice: Any) -> Optional[Dict[str, Any]]:
if tool_choice is None:
return None
if isinstance(tool_choice, str):
if tool_choice == "auto":
return {"functionCallingConfig": {"mode": "AUTO"}}
if tool_choice == "required":
return {"functionCallingConfig": {"mode": "ANY"}}
if tool_choice == "none":
return {"functionCallingConfig": {"mode": "NONE"}}
if isinstance(tool_choice, dict):
fn = tool_choice.get("function") or {}
name = fn.get("name")
if isinstance(name, str) and name:
return {"functionCallingConfig": {"mode": "ANY", "allowedFunctionNames": [name]}}
return None
def _normalize_thinking_config(config: Any) -> Optional[Dict[str, Any]]:
if not isinstance(config, dict) or not config:
return None
budget = config.get("thinkingBudget", config.get("thinking_budget"))
include = config.get("includeThoughts", config.get("include_thoughts"))
level = config.get("thinkingLevel", config.get("thinking_level"))
normalized: Dict[str, Any] = {}
if isinstance(budget, (int, float)):
normalized["thinkingBudget"] = int(budget)
if isinstance(include, bool):
normalized["includeThoughts"] = include
if isinstance(level, str) and level.strip():
normalized["thinkingLevel"] = level.strip().lower()
return normalized or None
def build_gemini_request(
*,
messages: List[Dict[str, Any]],
tools: Any = None,
tool_choice: Any = None,
temperature: Optional[float] = None,
max_tokens: Optional[int] = None,
top_p: Optional[float] = None,
stop: Any = None,
thinking_config: Any = None,
) -> Dict[str, Any]:
contents, system_instruction = _build_gemini_contents(messages)
request: Dict[str, Any] = {"contents": contents}
if system_instruction:
request["systemInstruction"] = system_instruction
gemini_tools = _translate_tools_to_gemini(tools)
if gemini_tools:
request["tools"] = gemini_tools
tool_config = _translate_tool_choice_to_gemini(tool_choice)
if tool_config:
request["toolConfig"] = tool_config
generation_config: Dict[str, Any] = {}
if temperature is not None:
generation_config["temperature"] = temperature
if max_tokens is not None:
generation_config["maxOutputTokens"] = max_tokens
if top_p is not None:
generation_config["topP"] = top_p
if stop:
generation_config["stopSequences"] = stop if isinstance(stop, list) else [str(stop)]
normalized_thinking = _normalize_thinking_config(thinking_config)
if normalized_thinking:
generation_config["thinkingConfig"] = normalized_thinking
if generation_config:
request["generationConfig"] = generation_config
return request
def _map_gemini_finish_reason(reason: str) -> str:
mapping = {
"STOP": "stop",
"MAX_TOKENS": "length",
"SAFETY": "content_filter",
"RECITATION": "content_filter",
"OTHER": "stop",
}
return mapping.get(str(reason or "").upper(), "stop")
def _tool_call_extra_from_part(part: Dict[str, Any]) -> Optional[Dict[str, Any]]:
sig = part.get("thoughtSignature")
if isinstance(sig, str) and sig:
return {"google": {"thought_signature": sig}}
return None
def _empty_response(model: str) -> SimpleNamespace:
message = SimpleNamespace(
role="assistant",
content="",
tool_calls=None,
reasoning=None,
reasoning_content=None,
reasoning_details=None,
)
choice = SimpleNamespace(index=0, message=message, finish_reason="stop")
usage = SimpleNamespace(
prompt_tokens=0,
completion_tokens=0,
total_tokens=0,
prompt_tokens_details=SimpleNamespace(cached_tokens=0),
)
return SimpleNamespace(
id=f"chatcmpl-{uuid.uuid4().hex[:12]}",
object="chat.completion",
created=int(time.time()),
model=model,
choices=[choice],
usage=usage,
)
def translate_gemini_response(resp: Dict[str, Any], model: str) -> SimpleNamespace:
candidates = resp.get("candidates") or []
if not isinstance(candidates, list) or not candidates:
return _empty_response(model)
cand = candidates[0] if isinstance(candidates[0], dict) else {}
content_obj = cand.get("content") if isinstance(cand, dict) else {}
parts = content_obj.get("parts") if isinstance(content_obj, dict) else []
text_pieces: List[str] = []
reasoning_pieces: List[str] = []
tool_calls: List[SimpleNamespace] = []
for index, part in enumerate(parts or []):
if not isinstance(part, dict):
continue
if part.get("thought") is True and isinstance(part.get("text"), str):
reasoning_pieces.append(part["text"])
continue
if isinstance(part.get("text"), str):
text_pieces.append(part["text"])
continue
fc = part.get("functionCall")
if isinstance(fc, dict) and fc.get("name"):
try:
args_str = json.dumps(fc.get("args") or {}, ensure_ascii=False)
except (TypeError, ValueError):
args_str = "{}"
tool_call = SimpleNamespace(
id=f"call_{uuid.uuid4().hex[:12]}",
type="function",
index=index,
function=SimpleNamespace(name=str(fc["name"]), arguments=args_str),
)
extra_content = _tool_call_extra_from_part(part)
if extra_content:
tool_call.extra_content = extra_content
tool_calls.append(tool_call)
finish_reason = "tool_calls" if tool_calls else _map_gemini_finish_reason(str(cand.get("finishReason") or ""))
usage_meta = resp.get("usageMetadata") or {}
usage = SimpleNamespace(
prompt_tokens=int(usage_meta.get("promptTokenCount") or 0),
completion_tokens=int(usage_meta.get("candidatesTokenCount") or 0),
total_tokens=int(usage_meta.get("totalTokenCount") or 0),
prompt_tokens_details=SimpleNamespace(
cached_tokens=int(usage_meta.get("cachedContentTokenCount") or 0),
),
)
reasoning = "".join(reasoning_pieces) or None
message = SimpleNamespace(
role="assistant",
content="".join(text_pieces) if text_pieces else None,
tool_calls=tool_calls or None,
reasoning=reasoning,
reasoning_content=reasoning,
reasoning_details=None,
)
choice = SimpleNamespace(index=0, message=message, finish_reason=finish_reason)
return SimpleNamespace(
id=f"chatcmpl-{uuid.uuid4().hex[:12]}",
object="chat.completion",
created=int(time.time()),
model=model,
choices=[choice],
usage=usage,
)
class _GeminiStreamChunk(SimpleNamespace):
pass
def _make_stream_chunk(
*,
model: str,
content: str = "",
tool_call_delta: Optional[Dict[str, Any]] = None,
finish_reason: Optional[str] = None,
reasoning: str = "",
) -> _GeminiStreamChunk:
delta_kwargs: Dict[str, Any] = {
"role": "assistant",
"content": None,
"tool_calls": None,
"reasoning": None,
"reasoning_content": None,
}
if content:
delta_kwargs["content"] = content
if tool_call_delta is not None:
tool_delta = SimpleNamespace(
index=tool_call_delta.get("index", 0),
id=tool_call_delta.get("id") or f"call_{uuid.uuid4().hex[:12]}",
type="function",
function=SimpleNamespace(
name=tool_call_delta.get("name") or "",
arguments=tool_call_delta.get("arguments") or "",
),
)
extra_content = tool_call_delta.get("extra_content")
if isinstance(extra_content, dict):
tool_delta.extra_content = extra_content
delta_kwargs["tool_calls"] = [tool_delta]
if reasoning:
delta_kwargs["reasoning"] = reasoning
delta_kwargs["reasoning_content"] = reasoning
delta = SimpleNamespace(**delta_kwargs)
choice = SimpleNamespace(index=0, delta=delta, finish_reason=finish_reason)
return _GeminiStreamChunk(
id=f"chatcmpl-{uuid.uuid4().hex[:12]}",
object="chat.completion.chunk",
created=int(time.time()),
model=model,
choices=[choice],
usage=None,
)
def _iter_sse_events(response: httpx.Response) -> Iterator[Dict[str, Any]]:
buffer = ""
for chunk in response.iter_text():
if not chunk:
continue
buffer += chunk
while "\n" in buffer:
line, buffer = buffer.split("\n", 1)
line = line.rstrip("\r")
if not line:
continue
if not line.startswith("data: "):
continue
data = line[6:]
if data == "[DONE]":
return
try:
payload = json.loads(data)
except json.JSONDecodeError:
logger.debug("Non-JSON Gemini SSE line: %s", data[:200])
continue
if isinstance(payload, dict):
yield payload
def translate_stream_event(event: Dict[str, Any], model: str, tool_call_indices: Dict[str, Dict[str, Any]]) -> List[_GeminiStreamChunk]:
candidates = event.get("candidates") or []
if not candidates:
return []
cand = candidates[0] if isinstance(candidates[0], dict) else {}
parts = ((cand.get("content") or {}).get("parts") or []) if isinstance(cand, dict) else []
chunks: List[_GeminiStreamChunk] = []
for part in parts:
if not isinstance(part, dict):
continue
if part.get("thought") is True and isinstance(part.get("text"), str):
chunks.append(_make_stream_chunk(model=model, reasoning=part["text"]))
continue
if isinstance(part.get("text"), str) and part["text"]:
chunks.append(_make_stream_chunk(model=model, content=part["text"]))
fc = part.get("functionCall")
if isinstance(fc, dict) and fc.get("name"):
name = str(fc["name"])
try:
args_str = json.dumps(fc.get("args") or {}, ensure_ascii=False, sort_keys=True)
except (TypeError, ValueError):
args_str = "{}"
thought_signature = part.get("thoughtSignature") if isinstance(part.get("thoughtSignature"), str) else ""
call_key = json.dumps({"name": name, "args": args_str, "thought_signature": thought_signature}, sort_keys=True)
slot = tool_call_indices.get(call_key)
if slot is None:
slot = {
"index": len(tool_call_indices),
"id": f"call_{uuid.uuid4().hex[:12]}",
}
tool_call_indices[call_key] = slot
chunks.append(
_make_stream_chunk(
model=model,
tool_call_delta={
"index": slot["index"],
"id": slot["id"],
"name": name,
"arguments": args_str,
"extra_content": _tool_call_extra_from_part(part),
},
)
)
finish_reason_raw = str(cand.get("finishReason") or "")
if finish_reason_raw:
mapped = "tool_calls" if tool_call_indices else _map_gemini_finish_reason(finish_reason_raw)
chunks.append(_make_stream_chunk(model=model, finish_reason=mapped))
return chunks
def gemini_http_error(response: httpx.Response) -> GeminiAPIError:
status = response.status_code
body_text = ""
body_json: Dict[str, Any] = {}
try:
body_text = response.text
except Exception:
body_text = ""
if body_text:
try:
parsed = json.loads(body_text)
if isinstance(parsed, dict):
body_json = parsed
except (ValueError, TypeError):
body_json = {}
err_obj = body_json.get("error") if isinstance(body_json, dict) else None
if not isinstance(err_obj, dict):
err_obj = {}
err_status = str(err_obj.get("status") or "").strip()
err_message = str(err_obj.get("message") or "").strip()
details_list = err_obj.get("details") if isinstance(err_obj.get("details"), list) else []
reason = ""
retry_after: Optional[float] = None
metadata: Dict[str, Any] = {}
for detail in details_list:
if not isinstance(detail, dict):
continue
type_url = str(detail.get("@type") or "")
if not reason and type_url.endswith("/google.rpc.ErrorInfo"):
reason_value = detail.get("reason")
if isinstance(reason_value, str):
reason = reason_value
md = detail.get("metadata")
if isinstance(md, dict):
metadata = md
header_retry = response.headers.get("Retry-After") or response.headers.get("retry-after")
if header_retry:
try:
retry_after = float(header_retry)
except (TypeError, ValueError):
retry_after = None
code = f"gemini_http_{status}"
if status == 401:
code = "gemini_unauthorized"
elif status == 429:
code = "gemini_rate_limited"
elif status == 404:
code = "gemini_model_not_found"
if err_message:
message = f"Gemini HTTP {status} ({err_status or 'error'}): {err_message}"
else:
message = f"Gemini returned HTTP {status}: {body_text[:500]}"
return GeminiAPIError(
message,
code=code,
status_code=status,
response=response,
retry_after=retry_after,
details={
"status": err_status,
"reason": reason,
"metadata": metadata,
"message": err_message,
},
)
class _GeminiChatCompletions:
def __init__(self, client: "GeminiNativeClient"):
self._client = client
def create(self, **kwargs: Any) -> Any:
return self._client._create_chat_completion(**kwargs)
class _AsyncGeminiChatCompletions:
def __init__(self, client: "AsyncGeminiNativeClient"):
self._client = client
async def create(self, **kwargs: Any) -> Any:
return await self._client._create_chat_completion(**kwargs)
class _GeminiChatNamespace:
def __init__(self, client: "GeminiNativeClient"):
self.completions = _GeminiChatCompletions(client)
class _AsyncGeminiChatNamespace:
def __init__(self, client: "AsyncGeminiNativeClient"):
self.completions = _AsyncGeminiChatCompletions(client)
class GeminiNativeClient:
"""Minimal OpenAI-SDK-compatible facade over Gemini's native REST API."""
def __init__(
self,
*,
api_key: str,
base_url: Optional[str] = None,
default_headers: Optional[Dict[str, str]] = None,
timeout: Any = None,
**_: Any,
) -> None:
self.api_key = api_key
normalized_base = (base_url or DEFAULT_GEMINI_BASE_URL).rstrip("/")
if normalized_base.endswith("/openai"):
normalized_base = normalized_base[: -len("/openai")]
self.base_url = normalized_base
self._default_headers = dict(default_headers or {})
self.chat = _GeminiChatNamespace(self)
self.is_closed = False
self._http = httpx.Client(timeout=timeout or httpx.Timeout(connect=15.0, read=600.0, write=30.0, pool=30.0))
def close(self) -> None:
self.is_closed = True
try:
self._http.close()
except Exception:
pass
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.close()
def _headers(self) -> Dict[str, str]:
headers = {
"Content-Type": "application/json",
"Accept": "application/json",
"x-goog-api-key": self.api_key,
"User-Agent": "hermes-agent (gemini-native)",
}
headers.update(self._default_headers)
return headers
def _create_chat_completion(
self,
*,
model: str = "gemini-2.5-flash",
messages: Optional[List[Dict[str, Any]]] = None,
stream: bool = False,
tools: Any = None,
tool_choice: Any = None,
temperature: Optional[float] = None,
max_tokens: Optional[int] = None,
top_p: Optional[float] = None,
stop: Any = None,
extra_body: Optional[Dict[str, Any]] = None,
timeout: Any = None,
**_: Any,
) -> Any:
thinking_config = None
if isinstance(extra_body, dict):
thinking_config = extra_body.get("thinking_config") or extra_body.get("thinkingConfig")
request = build_gemini_request(
messages=messages or [],
tools=tools,
tool_choice=tool_choice,
temperature=temperature,
max_tokens=max_tokens,
top_p=top_p,
stop=stop,
thinking_config=thinking_config,
)
if stream:
return self._stream_completion(model=model, request=request, timeout=timeout)
url = f"{self.base_url}/models/{model}:generateContent"
response = self._http.post(url, json=request, headers=self._headers(), timeout=timeout)
if response.status_code != 200:
raise gemini_http_error(response)
try:
payload = response.json()
except ValueError as exc:
raise GeminiAPIError(
f"Invalid JSON from Gemini native API: {exc}",
code="gemini_invalid_json",
status_code=response.status_code,
response=response,
) from exc
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:
response.read()
raise gemini_http_error(response)
tool_call_indices: Dict[str, int] = {}
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)
async def _create_chat_completion(self, **kwargs: Any) -> Any:
return await asyncio.to_thread(self._sync.chat.completions.create, **kwargs)
async def close(self) -> None:
await asyncio.to_thread(self._sync.close)