PayWatcher
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Payment verification without the payment processor.

Works like Stripe Payment Intents, but for on-chain USDC.

USDC on Base, Ethereum, Arbitrum & more.

Non-custodial. Flat-rate. Three API calls.

bash
curl -X POST https://api.paywatcher.dev/v1/payments \
  -H "x-api-key: pw_live_..." \
  -H "Content-Type: application/json" \
  -d '{"amount": "49.99", "currency": "USDC", "network": "arbitrum"}'
{
  "data": {
    "id": "pay_2x7k...",
    "status": "pending",
    "deposit_address": "0x1a2b...3c4d"
  }
}
Get API Key — FreeTry the Demo

The payment verification dilemma

Use Coinbase Commerce

Pay 1% per transaction.

$100 fee on a $10,000 payment. Custodial. Vendor lock-in.

Build it yourself

Parse Transfer events, handle reorgs, track confirmations.

Weeks of blockchain infra work. Ongoing maintenance burden.

The missing middle

PayWatcher

Non-custodial verification. Flat-rate pricing. Three API calls.

  • We never touch your funds
  • You keep your wallet
  • From $0 to $0.05 per verification

How It Works

Three steps to verify stablecoin payments. No custody, no complexity.

1

Create Payment Intent

Tell us what you expect

POST /v1/payments
{ "amount": "49.99", "currency": "USDC" }
2

Customer Sends USDC

They pay to the deposit address

Deposit Address:
0x1a2b...9z
Amount: 49.99 USDC
3

Webhook Fires

We notify you when it's confirmed

{
  "event": "payment.confirmed",
  "payment_id": "pay_2x7k...",
  "amount": "49.99"
}

See it in action →

Integrate in Minutes

A single API call to create a payment intent. A webhook when it's confirmed.

# Create a payment intent
curl -X POST https://api.paywatcher.dev/v1/payments \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": "49.99",
    "currency": "USDC",
    "network": "arbitrum"
  }'  # network is optional — defaults to "base"

# Check payment status
curl https://api.paywatcher.dev/v1/payments/pay_2x7k... \
  -H "x-api-key: YOUR_API_KEY"

See the full payment flow

USDC goes straight to your wallet. We just confirm it arrived.

Payment Flow Diagram: This diagram shows how a USDC payment is processed through five actors.

  1. Merchant App — The merchant's application that initiates a payment intent via the PayWatcher API.
  2. PayWatcher — The monitoring service that watches the Base blockchain for incoming payments and confirms them via webhook.
  3. Base Network — The Layer 2 blockchain where USDC transfers occur.
  4. Customer Wallet — The customer's cryptocurrency wallet that sends USDC directly to the merchant.
  5. Merchant Wallet — The merchant's wallet that receives USDC directly from the customer.

Flow: Step 1 — Merchant App sends POST /v1/payments to PayWatcher. Step 2 — Customer Wallet sends $1,000.03 USDC through Base Network to Merchant Wallet (fund flow). Step 3 — PayWatcher monitors Base Network for the exact payment amount (verification flow). Step 4 — PayWatcher sends a webhook (payment.confirmed) back to Merchant App.

Your funds. Your wallet. We just watch.

Supported Networks

Same API. Same $0.05. Any EVM chain.

baseBase
arbitrumArbitrum
ethereumEthereum
optimismOptimism
polygonPolygon
solanaSolanaComing Soon
avalancheAvalancheComing Soon

Simple, transparent pricing

Flat-fee per verification. No percentage cuts. No surprises.

Free
$0

Free

  • basic_dashboard
Start Free
Starter
$29/mo

Starter

  • basic_dashboard
  • webhook_config
  • api_access
Get Started
Pro
$99/mo

Pro

  • basic_dashboard
  • webhook_config
  • api_access
  • priority_support
Get Started
Enterprise
Custom

Enterprise

  • basic_dashboard
  • webhook_config
  • api_access
  • priority_support
  • dedicated_support
Get Started

The math is simple

$100 at Coinbase Commerce vs. $0.05 at PayWatcher

For a $10,000 payment. Same result, 2,000x cheaper.

Coinbase Commerce

  • 1% transaction fee
  • Custodial — they hold your funds
  • Vendor lock-in

PayWatcher

  • $0.05 flat fee per verification
  • Non-custodial — your keys, your wallet
  • No lock-in

You keep your keys. We just verify.

Start Free

Built on trust, not promises

Transparent infrastructure you can verify yourself.

Non-Custodial

Your keys, your wallet. We never touch your funds.

Base Network

Built on Base — fast, cheap, reliable.

USDC

Stablecoin payments — no volatility risk.

Built by masemIT

Austrian company. Transparent operations.

Get API Key

Get your API Key

Instant access — your API credentials will be sent to your inbox.