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POST
/
v1
/
pay
Send Payment
curl --request POST \
  --url https://api.example.com/v1/pay \
  --header 'Content-Type: application/json' \
  --data '
{
  "recipient": {
    "recipient.name": "<string>",
    "recipient.account_number": "<string>",
    "recipient.routing_number": "<string>",
    "recipient.email": "<string>"
  },
  "amount_usd": 123,
  "max_amount_usdc": 123,
  "description": "<string>",
  "idempotency_key": "<string>",
  "method": "<string>",
  "headers": {},
  "body": "<string>"
}
'
{
  "id": "<string>",
  "status": "<string>",
  "rail": "<string>",
  "amount_charged": 123,
  "fee": 123,
  "currency": "<string>",
  "recipient": "<string>",
  "tx_hash": {},
  "created_at": "<string>",
  "estimated_arrival": {},
  "response": {
    "response.status_code": 123,
    "response.headers": {},
    "response.body": "<string>"
  }
}
The unified pay endpoint is the recommended way to send any payment through Unwall. It automatically detects the recipient type and routes to the appropriate rail:
  • URL (e.g., https://api.example.com/...) — routes to the x402 protocol
  • EVM address (e.g., 0x742d...) — routes to on-chain USDC transfer
  • Bank details object — routes to fiat ACH off-ramp
Requires a bearer token with the pay permission. If the recipient is a URL, the token must also have the x402 permission.

​
Request Body

​
recipient
string | object
required
The payment recipient. Accepts one of three formats:
  • URL (string): An HTTPS URL for x402 protocol payments (e.g., "https://api.example.com/v1/data")
  • EVM address (string): A 0x-prefixed Ethereum address for USDC transfers (e.g., "0x742d35Cc6634C0532925a3b844Bc9e7595f2bD28")
  • Bank details (object): An object with name, account_number, routing_number, and email for fiat ACH payments
​
amount_usd
number
Payment amount in USD. Required for USDC transfer and fiat rails. Not used for x402 (the target API sets the price).
​
max_amount_usdc
integer
Maximum micro-USDC to pay for x402 requests (safety cap). 1 USDC = 1,000,000 micro-USDC. Only used when recipient is a URL.
​
description
string
Payment description for record-keeping. Max 500 characters.
​
idempotency_key
string
Unique key to prevent duplicate payments. Alphanumeric plus _, -, :, .. Max 255 characters.
​
method
string
default:"GET"
HTTP method for x402 requests. One of GET, POST, PUT, DELETE. Only used when recipient is a URL.
​
headers
object
Additional HTTP headers for x402 requests. Only used when recipient is a URL.
​
body
string
Request body for x402 POST or PUT requests. Only used when recipient is a URL.

​
Response

​
id
string
required
Unique transaction identifier.
​
status
string
required
Transaction status: pending, processing, completed, or failed.
​
rail
string
required
Payment rail used: x402, usdc_transfer, or fiat.
​
amount_charged
integer
required
Amount charged in rail-native units. Micro-USDC for x402 and usdc_transfer rails, cents for fiat rail.
​
fee
integer
required
Platform fee charged in rail-native units.
​
currency
string
required
Currency of the amount: usdc or usd.
​
recipient
string
required
Recipient identifier (URL, EVM address, or recipient name).
​
tx_hash
string | null
required
On-chain transaction hash for USDC and x402 payments. null for fiat payments.
​
created_at
string
required
ISO 8601 timestamp of when the payment was created.
​
estimated_arrival
string | null
required
Estimated delivery time for fiat payments (e.g., “2-3 business days”). null for crypto rails.
​
response
object | null
required
For x402 payments only — contains the proxied API response. null for other rails.

​
Examples

​
x402 Payment (URL recipient)

curl -X POST https://api.unwall.xyz/v1/pay \
  -H "Authorization: Bearer aw_live_xxxxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "recipient": "https://api.example.com/v1/data",
    "max_amount_usdc": 1000000,
    "description": "Fetch market data"
  }'
Response (200 OK)
{
  "id": "tx_x402_abc123",
  "status": "completed",
  "rail": "x402",
  "amount_charged": 500000,
  "fee": 7500,
  "currency": "usdc",
  "recipient": "https://api.example.com/v1/data",
  "tx_hash": "0x1a2b3c4d5e6f7890abcdef1234567890abcdef1234567890abcdef1234567890",
  "created_at": "2026-03-11T14:30:00Z",
  "estimated_arrival": null,
  "response": {
    "status_code": 200,
    "headers": {
      "content-type": "application/json"
    },
    "body": "{\"data\": [{\"id\": 1, \"value\": \"premium result\"}]}"
  }
}

​
USDC Transfer (EVM address recipient)

curl -X POST https://api.unwall.xyz/v1/pay \
  -H "Authorization: Bearer aw_live_xxxxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "recipient": "0x742d35Cc6634C0532925a3b844Bc9e7595f2bD28",
    "amount_usd": 50.00,
    "description": "Vendor payment"
  }'
Response (201 Created)
{
  "id": "tx_usdc_def456",
  "status": "processing",
  "rail": "usdc_transfer",
  "amount_charged": 50000000,
  "fee": 750000,
  "currency": "usdc",
  "recipient": "0x742d35Cc6634C0532925a3b844Bc9e7595f2bD28",
  "tx_hash": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
  "created_at": "2026-03-11T14:35:00Z",
  "estimated_arrival": null,
  "response": null
}

​
Fiat ACH Payment (Bank details recipient)

curl -X POST https://api.unwall.xyz/v1/pay \
  -H "Authorization: Bearer aw_live_xxxxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "recipient": {
      "name": "Acme Supplies Inc",
      "account_number": "9876543210",
      "routing_number": "021000021",
      "email": "billing@acme.com"
    },
    "amount_usd": 2500.00,
    "description": "Monthly supply order #47"
  }'
Response (201 Created)
{
  "id": "tx_fiat_ghi789",
  "status": "processing",
  "rail": "fiat",
  "amount_charged": 250000,
  "fee": 3750,
  "currency": "usd",
  "recipient": "Acme Supplies Inc",
  "tx_hash": null,
  "created_at": "2026-03-11T14:40:00Z",
  "estimated_arrival": "2-3 business days",
  "response": null
}