Fastapi

pip install x402 fastapi uvicorn python-dotenv pydantic

EVM_ADDRESS=0x...       # EVM wallet address to receive payments
SVM_ADDRESS=...         # Solana wallet address to receive payments
FACILITATOR_URL=https://facilitator.payai.network

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
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 = {
    "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",
    ),
    "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)


# 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)

uvicorn main:app --reload