app.py

# uvicorn app:app --host 0.0.0.0 --port 7860 --reload

from fastapi import FastAPI, Request, HTTPException, Response
from fastapi.middleware.cors import CORSMiddleware
import re, json
import httpx
import uuid

app = FastAPI()

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

@app.get("/")
def greet_json():
    return {"Hello": "World!"}

@app.get("/v1/{dest_url:path}")
async def gre_dest_url(dest_url: str):
    return dest_url

API_CLIENT = "genai-js/0.21.0"
DEFAULT_MODEL = "gemini-1.5-pro-latest"

async def transform_request(req: dict):
    # This is a placeholder, implement the transformation logic as needed
    return req

async def process_completions_response(data: dict, model: str, id: str):
    # Process the response to match the OpenAI format
    choices = []
    if "candidates" in data:
        for i, candidate in enumerate(data["candidates"]):
            message = {}
            if "content" in candidate:
                message["content"] = candidate["content"]
            else:
                message["content"] = ""
            message["role"] = "assistant"
            choices.append({
                "finish_reason": candidate.get("finishReason", "stop"),
                "index": i,
                "message": message
            })

    usage = {}
    if "usageMetadata" in data:
        usage = {
            "completion_tokens": data["usageMetadata"].get("tokenCount", 0),
            "prompt_tokens": 0,  # This value is not available in the response
            "total_tokens": data["usageMetadata"].get("tokenCount", 0)
        }

    response_data = {
        "id": id,
        "choices": choices,
        "created": 1678787675, # Replace with actual timestamp if available
        "model": model,
        "object": "chat.completion",
        "usage": usage
    }
    return json.dumps(response_data, ensure_ascii=False)

@app.post("/v1/{dest_url:path}")
async def proxy_url(dest_url: str, request: Request):
    body = await request.body()
    headers = dict(request.headers)

    # Remove Content-Length and Host headers
    if 'content-length' in headers:
        del headers['content-length']
    if 'host' in headers:
        del headers['host']

    # Extract API key from Authorization header
    auth = headers.get("Authorization")
    api_key = auth.split(" ")[1] if auth else None

    # Set required headers
    headers["x-goog-api-client"] = API_CLIENT
    if api_key:
        headers["x-goog-api-key"] = api_key
    headers['Content-Type'] = 'application/json'
    #if 'user-agent' in headers:
    #    del headers['user-agent']

    dest_url = re.sub('/', '://', dest_url, count=1)

    # Modify dest_url based on the endpoint
    if dest_url.endswith("/chat/completions"):
        model = DEFAULT_MODEL
        req_body = json.loads(body.decode('utf-8'))
        if 'model' in req_body:
            model = req_body['model']
            if model.startswith("models/"):
                model = model[7:]
        TASK = "generateContent"
        url = f"{dest_url.rsplit('/', 1)[0]}/{model}:{TASK}"

        async with httpx.AsyncClient() as client:
            try:
                # Forward the modified request
                response = await client.post(url, content=body, headers=headers)

                # Check response status code
                if response.status_code == 200:
                    # Process JSON response
                    if 'application/json' in response.headers.get('content-type', ''):
                        json_response = response.json()
                        json_response['id'] = f"chatcmpl-{uuid.uuid4()}"
                        processed_response = await process_completions_response(json_response, model, json_response['id'])
                        resp = Response(content=processed_response, media_type="application/json")
                        resp.headers["Access-Control-Allow-Origin"] = "*"
                        return resp
                    else:
                        return {"error": "Response is not in JSON format", "id": f"chatcmpl-{uuid.uuid4()}"}
                else:
                    # Convert error response to JSON format and return to the client
                    try:
                        error_data = response.json()
                        error_data['id'] = f"chatcmpl-{uuid.uuid4()}"
                    except ValueError:
                        error_data = {"status_code": response.status_code, "detail": response.text, "id": f"chatcmpl-{uuid.uuid4()}"}
                    print(f"Error response: {error_data}")
                    resp = Response(content=json.dumps(error_data, ensure_ascii=False), media_type="application/json")
                    resp.headers["Access-Control-Allow-Origin"] = "*"
                    return resp

            except httpx.RequestError as e:
                # Handle request errors
                print(f"Request error: {e}")
                raise HTTPException(status_code=500, detail=str(e))
    else:
        async with httpx.AsyncClient() as client:
            try:
                # Forward the original request
                response = await client.post(dest_url, content=body, headers=headers)

                # Check response status code
                if response.status_code == 200:
                    # Process JSON response
                    if 'application/json' in response.headers.get('content-type', ''):
                        json_response = response.json()
                        json_response['id'] = f"chatcmpl-{uuid.uuid4()}"
                        resp = Response(content=json.dumps(json_response), media_type="application/json")
                        resp.headers["Access-Control-Allow-Origin"] = "*"
                        return resp
                    else:
                        return {"error": "Response is not in JSON format", "id": f"chatcmpl-{uuid.uuid4()}"}
                else:
                    # Convert error response to JSON format and return to the client
                    try:
                        error_data = response.json()
                        error_data['id'] = f"chatcmpl-{uuid.uuid4()}"
                    except ValueError:
                        error_data = {"status_code": response.status_code, "detail": response.text, "id": f"chatcmpl-{uuid.uuid4()}"}
                    resp = Response(content=json.dumps(error_data), media_type="application/json")
                    resp.headers["Access-Control-Allow-Origin"] = "*"
                    return resp

            except httpx.RequestError as e:
                # Handle request errors
                raise HTTPException(status_code=500, detail=str(e))
# uvicorn app:app --host 0.0.0.0 --port 7860 --reload

from fastapi import FastAPI, Request, HTTPException, Response
import re, json
import httpx
import uuid

app = FastAPI()

@app.get("/")
def greet_json():
    return {"Hello": "World!"}

@app.get("/v1/{dest_url:path}")
async def gre_dest_url(dest_url: str):
    return dest_url

@app.post("/v1/{dest_url:path}")
async def proxy_url(dest_url: str, request: Request):
    body = await request.body()
    headers = dict(request.headers)  # 将请求头转换为字典
    
    # 移除 Content-Length 和 Host 头部
    if 'content-length' in headers:
        del headers['content-length']
    if 'host' in headers:
        del headers['host']
        
    headers['User-Agent']='PostmanRuntime/7.43.0'

    dest_url = re.sub('/', '://', dest_url, count=1)

    async with httpx.AsyncClient() as client:
        try:
            print(f"Request Headers: {headers}")
            # 向目标 URL 发送 POST 请求
            response = await client.post(dest_url, content=body, headers=headers)

            # 检查响应状态码
            if response.status_code == 200:
                # 检查响应内容类型是否为 JSON
                if 'application/json' in response.headers.get('content-type', ''):
                    json_response = response.json()
                    json_response['id'] = f"chatcmpl-{uuid.uuid4()}"
                    # resp = Response(content=str(json_response), media_type="application/json")
                    # resp = Response(content=str(json_response), media_type="application/json")
                    resp = Response(content=json.dumps(json_response), media_type="application/json")
                    resp.headers["Access-Control-Allow-Origin"] = "*"
                    return resp
                else:
                    return {"error": "Response is not in JSON format", "id": f"chatcmpl-{uuid.uuid4()}"}
            else:
                # 将错误响应转换为 JSON 格式并返回给客户端
                try:
                    error_data = response.json()
                    error_data['id'] = f"chatcmpl-{uuid.uuid4()}"
                except ValueError:
                    error_data = {"status_code": response.status_code, "detail": response.text, "id": f"chatcmpl-{uuid.uuid4()}"}
                resp = Response(content=str(error_data), media_type="application/json")
                resp.headers["Access-Control-Allow-Origin"] = "*"
                return resp
        
        except httpx.RequestError as e:
            # 处理请求错误
            raise HTTPException(status_code=500, detail=str(e))