app.py

from fastapi import FastAPI, Request, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from onnxruntime import InferenceSession
import numpy as np
import os
import uvicorn

app = FastAPI(title="ONNX Model API")

# CORS configuration
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

# Load ONNX model
session = InferenceSession("model.onnx")

# Essential for Spaces health checks
@app.get("/")
def read_root():
    return {"status": "ONNX Model API is running"}

# Main prediction endpoint
@app.post("/predict")
async def predict(request: Request):
    try:
        data = await request.json()
        input_ids = np.array(data["input_ids"], dtype=np.int64).reshape(1, -1)
        attention_mask = np.array(data["attention_mask"], dtype=np.int64).reshape(1, -1)
        
        outputs = session.run(None, {
            "input_ids": input_ids,
            "attention_mask": attention_mask
        })
        
        return {"embedding": outputs[0].tolist()}
    
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

# Special endpoint for Spaces compatibility
@app.post("/api/predict")
async def spaces_predict(request: Request):
    return await predict(request)

if __name__ == "__main__":
    uvicorn.run(
        app,
        host="0.0.0.0",
        port=7860,
        # Required for Spaces:
        proxy_headers=True,
        forwarded_allow_ips="*"
    )