from typing import Any, Dict, Optional
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from signing import get_signer
from signing.intents import build_evm_tx_intent
from signing.policy import SignerPolicyViolation
app = FastAPI(title="Sentinel Signer", version="1.0.0")
class SignRequest(BaseModel):
tx: Dict[str, Any]
chain_id: Optional[int] = None
intent: Optional[Dict[str, Any]] = None
@app.get("/address")
def get_address():
signer = get_signer()
return {"address": signer.get_address()}
@app.post("/sign_transaction")
def sign_transaction(req: SignRequest):
try:
signer = get_signer()
# "Firewall" Logic: verify intent matches tx
if req.intent:
calculated_intent = build_evm_tx_intent(req.tx, chain_id=req.chain_id)
if calculated_intent.to_dict() != req.intent:
raise HTTPException(status_code=400, detail="Intent mismatch: payload does not match declared intent.")
signed = signer.sign_transaction(req.tx, chain_id=req.chain_id)
return {"rawTransactionHex": "0x" + signed.rawTransaction.hex()}
except SignerPolicyViolation as e:
raise HTTPException(status_code=403, detail=f"Policy violation: {e.message}")
except Exception as e:
raise HTTPException(status_code=500, detail=str(e))
