Supported Networks#

PayWatcher supports USDC payments on multiple EVM-compatible blockchain networks. Use the network parameter when creating a payment to specify which chain to use.

If no network parameter is provided, payments default to Base ("base").

Chain Overview#

Network	Chain ID	USDC Contract	Confirmations	Explorer
`base`	8453	`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`	6	basescan.org
`ethereum`	1	`0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48`	12	etherscan.io
`arbitrum`	42161	`0xaf88d065e77c8cC2239327C5EDb3A432268e5831`	12	arbiscan.io
`optimism`	10	`0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85`	6	optimistic.etherscan.io
`polygon`	137	`0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359`	128	polygonscan.com

API Reference#

List Available Chains#

GET /v1/paywatcher/chains

Returns all supported blockchain networks with their configuration.

json

{
  "data": [
    {
      "network": "base",
      "name": "Base",
      "chain_id": 8453,
      "usdc_contract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "confirmations_required": 6,
      "explorer_url": "https://basescan.org"
    },
    {
      "network": "ethereum",
      "name": "Ethereum",
      "chain_id": 1,
      "usdc_contract": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
      "confirmations_required": 12,
      "explorer_url": "https://etherscan.io"
    }
  ]
}

Using Multi-Chain in Payments#

Specify the network parameter when creating a payment:

bash

curl -X POST https://api.masem.at/v1/payments \
  -H "x-api-key: mms_paywatcher_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": "100.00",
    "currency": "USDC",
    "chain": "arbitrum"
  }'

The response includes network, chainId, and explorerUrl:

json

{
  "data": {
    "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
    "amount": "100.00",
    "exactAmount": "100.000042",
    "status": "pending",
    "currency": "USDC",
    "chain": "arbitrum",
    "network": "arbitrum",
    "chainId": 42161,
    "explorerUrl": null,
    "confirmations": 0,
    "confirmationsRequired": 12
  }
}

Default Behavior#

Without network parameter: payments use "base" (Chain ID 8453)
The chain and network fields serve the same purpose — network is the preferred parameter
All webhook events include network and chain_id fields — see Webhooks

Next Steps#

Endpoints — Full API reference for creating and managing payments
Webhooks — Webhook events with multi-chain payload fields
Examples — Code examples in multiple languages