API Providers

import base64
import os
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
from payments_py import Payments, PaymentOptions
from payments_py.x402.helpers import build_payment_required

app = FastAPI()

payments = Payments.get_instance(
    PaymentOptions(nvm_api_key=os.environ['NVM_API_KEY'], environment='live')
)

payment_required = build_payment_required(
    plan_id=os.environ['NVM_PLAN_ID'],
    endpoint='/purchase-key',
    http_verb='POST',
    scheme='nvm:card-delegation',
)

# Pre-encode for the `payment-required` response header (per x402 spec §4.3).
payment_required_header = base64.b64encode(
    payment_required.model_dump_json(by_alias=True).encode()
).decode()

def send_402() -> JSONResponse:
    return JSONResponse(
        status_code=402,
        content=payment_required.model_dump(by_alias=True),
        headers={'payment-required': payment_required_header},
    )

@app.post('/purchase-key')
async def purchase_key(request: Request):
    token = request.headers.get('payment-signature')
    if not token:
        return send_402()

    verification = payments.facilitator.verify_permissions(
        payment_required=payment_required,
        x402_access_token=token,
    )
    if not verification.is_valid:
        return send_402()

    api_key = await provision_or_top_up(request)

    settlement = payments.facilitator.settle_permissions(
        payment_required=payment_required,
        x402_access_token=token,
    )

    # Settlement receipt in the `payment-response` header (per x402 spec §4.3).
    settlement_header = base64.b64encode(
        settlement.model_dump_json(by_alias=True).encode()
    ).decode()
    return JSONResponse(
        content={'apiKey': api_key},
        headers={'payment-response': settlement_header},
    )

POST https://api.live.nevermined.app/api/v1/x402/verify
POST https://api.live.nevermined.app/api/v1/x402/settle

{
  "paymentRequired": {
    "x402Version": 2,
    "resource": { "url": "/purchase-key", "mimeType": "application/json" },
    "accepts": [{
      "scheme": "nvm:card-delegation",
      "network": "stripe",
      "planId": "<your-plan-id>",
      "extra": { "version": "1", "httpVerb": "POST" }
    }],
    "extensions": {}
  },
  "x402AccessToken": "<token from the payment-signature header>"
}

# 0. Pre-build the PaymentRequired JSON for your endpoint (see body shape above)
PAYMENT_REQUIRED='{"x402Version":2,"resource":{"url":"/purchase-key","mimeType":"application/json"},"accepts":[{"scheme":"nvm:card-delegation","network":"stripe","planId":"<your-plan-id>","extra":{"version":"1","httpVerb":"POST"}}],"extensions":{}}'

# 1. On request: read the payment-signature header
TOKEN="$(http_header payment-signature)"

# 2. Verify
curl -s -X POST https://api.live.nevermined.app/api/v1/x402/verify \
  -H 'Content-Type: application/json' \
  -d "$(jq -n --arg pr "$PAYMENT_REQUIRED" --arg t "$TOKEN" '{
        paymentRequired: ($pr | fromjson),
        x402AccessToken: $t
      }')"
# → on isValid=false, return 402 with payment-required header set

# 3. Run business logic (provision/top-up the API key)

# 4. Settle
curl -s -X POST https://api.live.nevermined.app/api/v1/x402/settle \
  -H 'Content-Type: application/json' \
  -d "$(jq -n --arg pr "$PAYMENT_REQUIRED" --arg t "$TOKEN" '{
        paymentRequired: ($pr | fromjson),
        x402AccessToken: $t
      }')"

# 5. Return 200 with the credential

import os
from fastapi import FastAPI, Request
from payments_py import Payments, PaymentOptions
from payments_py.x402.fastapi import PaymentMiddleware

app = FastAPI()

payments = Payments.get_instance(
    PaymentOptions(nvm_api_key=os.environ['NVM_API_KEY'], environment='live')
)

app.add_middleware(
    PaymentMiddleware,
    payments=payments,
    routes={
        'POST /purchase-key': {
            'plan_id': os.environ['NVM_PLAN_ID'],
            'scheme': 'nvm:card-delegation',
        },
    },
)

@app.post('/purchase-key')
async def purchase_key(request: Request):
    api_key = await provision_or_top_up(request)
    return {'apiKey': api_key}

token_res = payments.x402.get_x402_access_token(
    YOUR_PLAN_ID,
    None,
    {
        'scheme': 'nvm:card-delegation',
        'delegationConfig': {
            'providerPaymentMethodId': 'pm_...',
            'spendingLimitCents': 700,
            'durationSecs': 3600,
        },
    },
)
access_token = token_res['accessToken']

res = requests.post(
    'https://your-api.com/purchase-key',
    headers={'payment-signature': access_token},
)