Crypto Payment API for Developers: Webhooks, Keys, and Integration Guide

If you're building a product that needs to accept cryptocurrency payments — or automate payment workflows — Vulta's REST API and webhook system give you programmatic control over the entire payment lifecycle.

This article covers what the API offers, how webhooks work, and what you need to integrate.

Who This Is For

• SaaS developers who want to trigger payment requests programmatically
• Developers building billing or invoicing systems
• Teams that need real-time payment event notifications
• Anyone who wants to automate payment link creation and tracking

What the Vulta API Provides

Payment Link Management

• Create payment links via API
• List, retrieve, and manage payment requests
• Set amounts, currencies, descriptions, and payout destinations

Payout Destination Management

• Read wallet groups and destinations
• Assign destinations to programmatically created payment requests

Transaction Events

• Real-time webhook notifications on payment events
• payment.detected — transaction seen on-chain
• payment.confirmed — transaction confirmed with sufficient blocks

API Keys

To use the API, you need an API key. Keys are available on the Business plan.

Generate a key from your Vulta dashboard under Settings > API Keys. Keys are long-lived — keep them secret and never expose them client-side.

Making Your First API Request

Base URL: https://vulta.one/api

Authentication: Pass your API key in the Authorization header:

Authorization: Bearer YOUR_API_KEY

Create a payment request:

curl -X POST https://vulta.one/api/payment-requests \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "pricing_mode": "fixed_fiat",
    "amount_fiat": "150.00",
    "fiat_currency": "USD",
    "external_reference_id": "order_789",
    "payout_destination_ids": ["dest_abc123"]
  }'

The response includes the payment request ID and a hosted checkout URL you can share with or redirect your user to.

Webhooks

Webhooks deliver real-time event notifications to your server when payment events occur.

Configure a webhook endpoint from your Vulta dashboard under Settings > Webhooks.

Event types:

• payment.detected — transaction seen on-chain, payment likely
• payment.confirmed — transaction confirmed, payment complete

Payload structure:

{
  "event": "payment.confirmed",
  "payment_id": "req_abc123",
  "amount_fiat": "150.00",
  "fiat_currency": "USD",
  "network": "Ethereum",
  "asset": "USDC",
  "wallet_address": "0xabc...",
  "transaction_hash": "0xdef...",
  "external_reference_id": "order_789",
  "timestamp": "2026-03-15T14:23:01Z"
}

HMAC Signature Verification

Every webhook request includes an X-Vulta-Signature header. Verify it to ensure the request came from Vulta:

import hmac
import hashlib

def verify_webhook(payload: bytes, signature: str, secret: str) -> bool:
    expected = hmac.new(
        secret.encode(),
        payload,
        hashlib.sha256
    ).hexdigest()
    return hmac.compare_digest(expected, signature)

Always verify the signature before processing webhook events.

Typical Integration Pattern

1. User initiates purchase in your app
2. Your backend calls POST /payment-requests to create a payment request
3. You redirect user to the checkout URL or embed the iframe
4. User pays with card or crypto
5. Vulta sends payment.confirmed webhook to your endpoint
6. Your backend verifies signature, updates order status, provisions access

Plan Requirements

The API and webhooks are available on the Business plan only. For simple payment link creation without programmatic automation, the dashboard UI handles this on all plans.

Documentation

Full API reference: vulta.one/developers

Upgrade to Business and start building with the Vulta API.