main.py

import os

from dotenv import load_dotenv
from fastapi import FastAPI
from pydantic import BaseModel

from x402.http import FacilitatorConfig, HTTPFacilitatorClient, PaymentOption
from x402.http.middleware.fastapi import PaymentMiddlewareASGI, payment_middleware  # noqa: F401
from x402.http.types import RouteConfig
from x402.mechanisms.evm.exact import ExactEvmServerScheme
from x402.mechanisms.svm.exact import ExactSvmServerScheme
from x402.schemas import AssetAmount, Network
from x402.server import x402ResourceServer

load_dotenv()

# Config
EVM_ADDRESS = os.getenv("EVM_ADDRESS")
SVM_ADDRESS = os.getenv("SVM_ADDRESS")
EVM_NETWORK: Network = "eip155:84532"  # Base Sepolia
SVM_NETWORK: Network = "solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1"  # Solana Devnet
FACILITATOR_URL = os.getenv("FACILITATOR_URL", "https://x402.org/facilitator")

if not EVM_ADDRESS or not SVM_ADDRESS:
    raise ValueError("Missing required environment variables")


# Response schemas
class WeatherReport(BaseModel):
    weather: str
    temperature: int


class WeatherResponse(BaseModel):
    report: WeatherReport


class PremiumContentResponse(BaseModel):
    content: str


# App
app = FastAPI()


# x402 Middleware
facilitator = HTTPFacilitatorClient(FacilitatorConfig(url=FACILITATOR_URL))
server = x402ResourceServer(facilitator)
server.register(EVM_NETWORK, ExactEvmServerScheme())
server.register(SVM_NETWORK, ExactSvmServerScheme())

routes = {
    # a first way to pay for the weather report, it's a string
    "GET /weather": RouteConfig(
        accepts=[
            PaymentOption(
                scheme="exact",
                pay_to=EVM_ADDRESS,
                price="$0.01",
                network=EVM_NETWORK,
            ),
            PaymentOption(
                scheme="exact",
                pay_to=SVM_ADDRESS,
                price="$0.01",
                network=SVM_NETWORK,
            ),
        ],
        mime_type="application/json",
        description="Weather report",
    ),
    # a second way to pay for the premium content, it's an AssetAmount object
    "GET /premium/*": RouteConfig(
        accepts=[
            PaymentOption(
                scheme="exact",
                pay_to=EVM_ADDRESS,
                price=AssetAmount(
                    amount="10000",  # $0.01 USDC
                    asset="0x036CbD53842c5426634e7929541eC2318f3dCF7e",
                    extra={"name": "USDC", "version": "2"},
                ),
                network=EVM_NETWORK,
            ),
            PaymentOption(
                scheme="exact",
                pay_to=SVM_ADDRESS,
                price="$0.01",
                network=SVM_NETWORK,
            ),
        ],
        mime_type="application/json",
        description="Premium content",
    ),
}
app.add_middleware(PaymentMiddlewareASGI, routes=routes, server=server)
# app.middleware("http")(payment_middleware(routes=routes, server=server))  # Alternative way to register the middleware


# Routes
@app.get("/health")
async def health_check() -> dict[str, str]:
    return {"status": "ok"}


@app.get("/weather")
async def get_weather() -> WeatherResponse:
    return WeatherResponse(report=WeatherReport(weather="sunny", temperature=70))


@app.get("/premium/content")
async def get_premium_content() -> PremiumContentResponse:
    return PremiumContentResponse(content="This is premium content")


if __name__ == "__main__":
    import uvicorn

    uvicorn.run(app, host="0.0.0.0", port=4021)