import os import json import requests import re import uvicorn import base64 from datetime import datetime from fastapi import FastAPI, Request, Response, HTTPException, Depends from fastapi.responses import StreamingResponse from fastapi.security import HTTPBasic, HTTPBasicCredentials from http.server import BaseHTTPRequestHandler, HTTPServer from urllib.parse import urlparse, parse_qs import ijson from dotenv import load_dotenv from google.oauth2.credentials import Credentials from google_auth_oauthlib.flow import Flow from google.auth.transport.requests import Request as GoogleAuthRequest # Load environment variables from .env file load_dotenv() # --- Configuration --- CLIENT_ID = "681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com" CLIENT_SECRET = "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" SCOPES = [ "https://www.googleapis.com/auth/cloud-platform", "https://www.googleapis.com/auth/userinfo.email", "https://www.googleapis.com/auth/userinfo.profile", "openid", ] GEMINI_DIR = os.path.dirname(os.path.abspath(__file__)) # Same directory as the script CREDENTIAL_FILE = os.path.join(GEMINI_DIR, "oauth_creds.json") CODE_ASSIST_ENDPOINT = "https://cloudcode-pa.googleapis.com" GEMINI_PORT = int(os.getenv("GEMINI_PORT", "8888")) # Default to 8888 if not set GEMINI_AUTH_PASSWORD = os.getenv("GEMINI_AUTH_PASSWORD", "123456") # Default password # --- Global State --- credentials = None user_project_id = None app = FastAPI() security = HTTPBasic() def authenticate_user(request: Request): """Authenticate the user with multiple methods.""" # Check for API key in query parameters first (for Gemini client compatibility) api_key = request.query_params.get("key") if api_key and api_key == GEMINI_AUTH_PASSWORD: return "api_key_user" # Check for API key in Authorization header (Bearer token format) auth_header = request.headers.get("authorization", "") if auth_header.startswith("Bearer ") and auth_header[7:] == GEMINI_AUTH_PASSWORD: return "bearer_user" # Check for HTTP Basic Authentication if auth_header.startswith("Basic "): try: encoded_credentials = auth_header[6:] decoded_credentials = base64.b64decode(encoded_credentials).decode('utf-8') username, password = decoded_credentials.split(':', 1) if password == GEMINI_AUTH_PASSWORD: return username except Exception: pass # If none of the authentication methods work raise HTTPException( status_code=401, detail="Invalid authentication credentials. Use HTTP Basic Auth, Bearer token, or 'key' query parameter.", headers={"WWW-Authenticate": "Basic"}, ) # Helper class to adapt a generator of bytes into a file-like object # that ijson can read from. class _GeneratorStream: def __init__(self, generator): self.generator = generator self.buffer = b'' def read(self, size=-1): # This read implementation is crucial for streaming. # It must not block to read the entire stream if size is -1. if size == -1: # If asked to read all, return what's in the buffer and get one more chunk. try: self.buffer += next(self.generator) except StopIteration: pass data = self.buffer self.buffer = b'' return data # Otherwise, read from the generator until we have enough bytes. while len(self.buffer) < size: try: self.buffer += next(self.generator) except StopIteration: # Generator is exhausted. break data = self.buffer[:size] self.buffer = self.buffer[size:] return data class _OAuthCallbackHandler(BaseHTTPRequestHandler): auth_code = None def do_GET(self): query_components = parse_qs(urlparse(self.path).query) code = query_components.get("code", [None])[0] if code: _OAuthCallbackHandler.auth_code = code self.send_response(200) self.send_header("Content-type", "text/html") self.end_headers() self.wfile.write(b"

Authentication successful!

You can close this window and restart the proxy.

") else: self.send_response(400) self.send_header("Content-type", "text/html") self.end_headers() self.wfile.write(b"

Authentication failed.

Please try again.

") def get_user_project_id(creds): """Gets the user's project ID from environment variable, cache, or by probing the API.""" global user_project_id if user_project_id: return user_project_id # First, check for environment variable override env_project_id = os.getenv("GEMINI_PROJECT_ID") if env_project_id: user_project_id = env_project_id print(f"Using project ID from environment variable: {user_project_id}") # Save the environment project ID to cache for consistency save_credentials(creds, user_project_id) return user_project_id # Second, try to load project ID from credential file if os.path.exists(CREDENTIAL_FILE): try: with open(CREDENTIAL_FILE, "r") as f: creds_data = json.load(f) cached_project_id = creds_data.get("project_id") if cached_project_id: user_project_id = cached_project_id print(f"Loaded project ID from cache: {user_project_id}") return user_project_id except Exception as e: print(f"Could not load project ID from cache: {e}") # If not found in environment or cache, probe for it print("Project ID not found in environment or cache. Probing for user project ID...") headers = { "Authorization": f"Bearer {creds.token}", "Content-Type": "application/json", } probe_payload = { "cloudaicompanionProject": "gcp-project", "metadata": { "ideType": "VSCODE", "pluginType": "GEMINI" } } try: resp = requests.post( f"{CODE_ASSIST_ENDPOINT}/v1internal:loadCodeAssist", data=json.dumps(probe_payload), headers=headers, ) resp.raise_for_status() data = resp.json() user_project_id = data.get("cloudaicompanionProject") if not user_project_id: raise ValueError("Could not find 'cloudaicompanionProject' in loadCodeAssist response.") print(f"Successfully fetched user project ID: {user_project_id}") # Save the project ID to the credential file for future use save_credentials(creds, user_project_id) print("Project ID saved to credential file for future use.") return user_project_id except requests.exceptions.HTTPError as e: print(f"Error fetching project ID: {e.response.text}") raise def save_credentials(creds, project_id=None): os.makedirs(GEMINI_DIR, exist_ok=True) creds_data = { "access_token": creds.token, "refresh_token": creds.refresh_token, "scope": " ".join(creds.scopes), "token_type": "Bearer", "expiry_date": creds.expiry.isoformat() if creds.expiry else None, } # If project_id is provided, save it; otherwise preserve existing project_id if project_id: creds_data["project_id"] = project_id elif os.path.exists(CREDENTIAL_FILE): try: with open(CREDENTIAL_FILE, "r") as f: existing_data = json.load(f) if "project_id" in existing_data: creds_data["project_id"] = existing_data["project_id"] except Exception: pass # If we can't read existing file, just continue without project_id with open(CREDENTIAL_FILE, "w") as f: json.dump(creds_data, f) def get_credentials(): """Loads credentials from cache or initiates the OAuth 2.0 flow.""" global credentials if credentials: if credentials.valid: return credentials if credentials.expired and credentials.refresh_token: print("Refreshing expired credentials...") try: credentials.refresh(GoogleAuthRequest()) save_credentials(credentials) print("Credentials refreshed successfully.") return credentials except Exception as e: print(f"Could not refresh token: {e}. Attempting to load from file.") if os.path.exists(CREDENTIAL_FILE): try: with open(CREDENTIAL_FILE, "r") as f: creds_data = json.load(f) # Load project ID if available global user_project_id cached_project_id = creds_data.get("project_id") if cached_project_id: user_project_id = cached_project_id print(f"Loaded project ID from credential file: {user_project_id}") expiry = None expiry_str = creds_data.get("expiry_date") if expiry_str: if not isinstance(expiry_str, str) or not expiry_str.strip(): expiry = None elif expiry_str.endswith('Z'): expiry_str = expiry_str[:-1] + '+00:00' expiry = datetime.fromisoformat(expiry_str) else: expiry = datetime.fromisoformat(expiry_str) credentials = Credentials( token=creds_data.get("access_token"), refresh_token=creds_data.get("refresh_token"), token_uri="https://oauth2.googleapis.com/token", client_id=CLIENT_ID, client_secret=CLIENT_SECRET, scopes=SCOPES, expiry=expiry ) if credentials.expired and credentials.refresh_token: print("Loaded credentials from file are expired. Refreshing...") credentials.refresh(GoogleAuthRequest()) save_credentials(credentials) print("Successfully loaded credentials from cache.") return credentials except Exception as e: print(f"Could not load cached credentials: {e}. Starting new login.") client_config = { "installed": { "client_id": CLIENT_ID, "client_secret": CLIENT_SECRET, "auth_uri": "https://accounts.google.com/o/oauth2/auth", "token_uri": "https://oauth2.googleapis.com/token", } } flow = Flow.from_client_config( client_config, scopes=SCOPES, redirect_uri="http://localhost:8080" ) auth_url, _ = flow.authorization_url(access_type="offline", prompt="consent") print(f"\nPlease open this URL in your browser to log in:\n{auth_url}\n") server = HTTPServer(("", 8080), _OAuthCallbackHandler) server.handle_request() auth_code = _OAuthCallbackHandler.auth_code if not auth_code: print("Failed to retrieve authorization code.") return None flow.fetch_token(code=auth_code) credentials = flow.credentials save_credentials(credentials) print("Authentication successful! Credentials saved.") return credentials @app.post("/{full_path:path}") async def proxy_request(request: Request, full_path: str, username: str = Depends(authenticate_user)): creds = get_credentials() if not creds: return Response(content="Authentication failed. Please restart the proxy to log in.", status_code=500) # Only check if credentials are properly formed and not expired locally if not creds.valid: if creds.expired and creds.refresh_token: print("Credentials expired locally. Refreshing...") try: creds.refresh(GoogleAuthRequest()) save_credentials(creds) print("Credentials refreshed successfully.") except Exception as e: print(f"Could not refresh token during request: {e}") return Response(content="Token refresh failed. Please restart the proxy to re-authenticate.", status_code=500) else: print("Credentials are invalid locally and cannot be refreshed.") return Response(content="Invalid credentials. Please restart the proxy to re-authenticate.", status_code=500) proj_id = get_user_project_id(creds) if not proj_id: return Response(content="Failed to get user project ID.", status_code=500) post_data = await request.body() path = f"/{full_path}" model_name_from_url = None action = None model_match = re.match(r"/(v\d+(?:beta)?)/models/([^:]+):(\w+)", path) is_streaming = False if model_match: model_name_from_url = model_match.group(2) action = model_match.group(3) target_url = f"{CODE_ASSIST_ENDPOINT}/v1internal:{action}" if "stream" in action.lower(): is_streaming = True else: target_url = f"{CODE_ASSIST_ENDPOINT}{path}" # Remove authentication query parameters before forwarding to Google API query_params = dict(request.query_params) # Remove our authentication parameters query_params.pop("key", None) # Add remaining query parameters to target URL if any if query_params: from urllib.parse import urlencode target_url += "?" + urlencode(query_params) try: incoming_json = json.loads(post_data) final_model = model_name_from_url if model_match else incoming_json.get("model") # Set default safety settings to BLOCK_NONE if not specified by user safety_settings = incoming_json.get("safetySettings") if not safety_settings: safety_settings = [ {"category": "HARM_CATEGORY_HARASSMENT", "threshold": "BLOCK_NONE"}, {"category": "HARM_CATEGORY_HATE_SPEECH", "threshold": "BLOCK_NONE"}, {"category": "HARM_CATEGORY_SEXUALLY_EXPLICIT", "threshold": "BLOCK_NONE"}, {"category": "HARM_CATEGORY_DANGEROUS_CONTENT", "threshold": "BLOCK_NONE"}, {"category": "HARM_CATEGORY_CIVIC_INTEGRITY", "threshold": "BLOCK_NONE"} ] structured_payload = { "model": final_model, "project": proj_id, "request": { "contents": incoming_json.get("contents"), "systemInstruction": incoming_json.get("systemInstruction"), "cachedContent": incoming_json.get("cachedContent"), "tools": incoming_json.get("tools"), "toolConfig": incoming_json.get("toolConfig"), "safetySettings": safety_settings, "generationConfig": incoming_json.get("generationConfig"), }, } structured_payload["request"] = { k: v for k, v in structured_payload["request"].items() if v is not None } final_post_data = json.dumps(structured_payload) except (json.JSONDecodeError, AttributeError): final_post_data = post_data headers = { "Authorization": f"Bearer {creds.token}", "Content-Type": "application/json", # We remove 'Accept-Encoding' to allow the server to send gzip, # which it seems to stream correctly. We will decompress on the fly. } if is_streaming: async def stream_generator(): try: print(f"[STREAM] Starting streaming request to: {target_url}") print(f"[STREAM] Request payload size: {len(final_post_data)} bytes") # Make the initial streaming request resp = requests.post(target_url, data=final_post_data, headers=headers, stream=True) print(f"[STREAM] Response status: {resp.status_code}") print(f"[STREAM] Response headers: {dict(resp.headers)}") # If we get a 401, try refreshing the token and retry once if resp.status_code == 401 and creds.refresh_token: print("[STREAM] Received 401 from Google API. Attempting to refresh token and retry...") resp.close() # Close the failed response try: creds.refresh(GoogleAuthRequest()) save_credentials(creds) print("[STREAM] Token refreshed successfully. Retrying streaming request...") # Update headers with new token and retry headers["Authorization"] = f"Bearer {creds.token}" resp = requests.post(target_url, data=final_post_data, headers=headers, stream=True) print(f"[STREAM] Retry request status: {resp.status_code}") except Exception as e: print(f"[STREAM] Could not refresh token after 401 error: {e}") error_message = json.dumps({"error": {"message": "Token refresh failed after 401 error. Please restart the proxy to re-authenticate."}}) yield f"data: {error_message}\n\n" return with resp: resp.raise_for_status() buffer = "" brace_count = 0 in_array = False chunk_count = 0 total_bytes = 0 objects_yielded = 0 print(f"[STREAM] Starting to process chunks...") for chunk in resp.iter_content(chunk_size=1024): if isinstance(chunk, bytes): chunk = chunk.decode('utf-8', errors='replace') chunk_count += 1 chunk_size = len(chunk) if chunk else 0 total_bytes += chunk_size buffer += chunk # Process complete JSON objects from the buffer processing_iterations = 0 while buffer: processing_iterations += 1 if processing_iterations > 100: # Prevent infinite loops break buffer = buffer.lstrip() if not buffer: break # Handle array start if buffer.startswith('[') and not in_array: buffer = buffer[1:].lstrip() in_array = True continue # Handle array end if buffer.startswith(']'): break # Skip commas between objects if buffer.startswith(','): buffer = buffer[1:].lstrip() continue # Look for complete JSON objects if buffer.startswith('{'): brace_count = 0 in_string = False escape_next = False end_pos = -1 for i, char in enumerate(buffer): if escape_next: escape_next = False continue if char == '\\': escape_next = True continue if char == '"' and not escape_next: in_string = not in_string continue if not in_string: if char == '{': brace_count += 1 elif char == '}': brace_count -= 1 if brace_count == 0: end_pos = i + 1 break if end_pos > 0: # Found complete JSON object json_str = buffer[:end_pos] buffer = buffer[end_pos:].lstrip() try: obj = json.loads(json_str) if "response" in obj: response_chunk = obj["response"] objects_yielded += 1 response_json = json.dumps(response_chunk) yield f"data: {response_json}\n\n" except json.JSONDecodeError as e: continue else: # Incomplete object, wait for more data break else: # Skip unexpected characters buffer = buffer[1:] except requests.exceptions.RequestException as e: print(f"Error during streaming request: {e}") error_message = json.dumps({"error": {"message": f"Upstream request failed: {e}"}}) yield f"data: {error_message}\n\n" except Exception as e: print(f"An unexpected error occurred during streaming: {e}") error_message = json.dumps({"error": {"message": f"An unexpected error occurred: {e}"}}) yield f"data: {error_message}\n\n" return StreamingResponse(stream_generator(), media_type="text/event-stream") else: # Make the request resp = requests.post(target_url, data=final_post_data, headers=headers) # If we get a 401, try refreshing the token and retry once if resp.status_code == 401 and creds.refresh_token: print("Received 401 from Google API. Attempting to refresh token and retry...") try: creds.refresh(GoogleAuthRequest()) save_credentials(creds) print("Token refreshed successfully. Retrying request...") # Update headers with new token and retry headers["Authorization"] = f"Bearer {creds.token}" resp = requests.post(target_url, data=final_post_data, headers=headers) print(f"Retry request status: {resp.status_code}") except Exception as e: print(f"Could not refresh token after 401 error: {e}") return Response(content="Token refresh failed after 401 error. Please restart the proxy to re-authenticate.", status_code=500) if resp.status_code == 200: try: google_api_response = resp.json() # The actual response is nested under the "response" key standard_gemini_response = google_api_response.get("response") # The standard client expects a list containing the response object return Response(content=json.dumps([standard_gemini_response]), status_code=200, media_type="application/json") except (json.JSONDecodeError, AttributeError) as e: print(f"Error converting to standard Gemini format: {e}") # Fallback to sending the original content if conversion fails return Response(content=resp.content, status_code=resp.status_code, media_type=resp.headers.get("Content-Type")) else: return Response(content=resp.content, status_code=resp.status_code, media_type=resp.headers.get("Content-Type")) if __name__ == "__main__": print("Initializing credentials...") creds = get_credentials() if creds: get_user_project_id(creds) print(f"\nStarting Gemini proxy server on http://localhost:{GEMINI_PORT}") print("Send your Gemini API requests to this address.") print(f"Authentication required - Password: {GEMINI_AUTH_PASSWORD}") print("Use HTTP Basic Authentication with any username and the password above.") uvicorn.run(app, host="0.0.0.0", port=GEMINI_PORT) else: print("\nCould not obtain credentials. Please authenticate and restart the server.")