Build payments that settle on-chain.

curl --request POST https://cryptopayin.com/v1/payments \
  --header "Authorization: Bearer $CPI_SECRET_KEY" \
  --header "Content-Type: application/json" \
  --header "Idempotency-Key: order_1042" \
  --data '{
    "amount": 49.99,
    "currency": "USD",
    "asset": "ETH",
    "order_ref": "order_1042",
    "redirect_url": "https://shop.example/orders/1042/paid"
  }'

const response = await fetch("https://cryptopayin.com/v1/payments", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.CPI_SECRET_KEY}`,
    "Content-Type": "application/json",
    "Idempotency-Key": "order_1042"
  },
  body: JSON.stringify({
    amount: 49.99, currency: "USD", asset: "ETH",
    order_ref: "order_1042",
    redirect_url: "https://shop.example/orders/1042/paid"
  })
});
if (!response.ok) throw new Error(await response.text());
const payment = await response.json();

$payload = json_encode([
    'amount' => 49.99, 'currency' => 'USD', 'asset' => 'ETH',
    'order_ref' => 'order_1042',
    'redirect_url' => 'https://shop.example/orders/1042/paid',
]);
$ch = curl_init('https://cryptopayin.com/v1/payments');
curl_setopt_array($ch, [
    CURLOPT_POST => true, CURLOPT_POSTFIELDS => $payload,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer ' . getenv('CPI_SECRET_KEY'),
        'Content-Type: application/json',
        'Idempotency-Key: order_1042',
    ],
]);
$payment = json_decode(curl_exec($ch), true, flags: JSON_THROW_ON_ERROR);

import os, requests

response = requests.post(
    "https://cryptopayin.com/v1/payments",
    headers={
        "Authorization": f"Bearer {os.environ['CPI_SECRET_KEY']}",
        "Idempotency-Key": "order_1042",
    },
    json={
        "amount": 49.99, "currency": "USD", "asset": "ETH",
        "order_ref": "order_1042",
        "redirect_url": "https://shop.example/orders/1042/paid",
    }, timeout=15,
)
response.raise_for_status()
payment = response.json()

{
  "id": "P-9F27C1E4KD",
  "object": "payment",
  "status": "created",
  "amount": 49.99,
  "amount_decimal": "49.99",
  "amount_minor": 4999,
  "currency": "USD",
  "currency_minor_units": 2,
  "amount_usd": 49.99,
  "amount_usd_cents": 4999,
  "fx_rate_usd": "1.000000000000",
  "fx_source": "fixed:USD",
  "fx_observed_at": "2026-07-17T13:00:00+00:00",
  "fx_discrepancy_bps": 0,
  "asset": "ETH",
  "network": "mainnet",
  "crypto_amount": "0.01388612",
  "crypto_received": "0",
  "deposit_address": "0x71b8c3d4700000000000000000000000000084e2",
  "exchange_rate": "3600.00000000",
  "exchange_rate_currency": "USD",
  "exchange_rate_source": "median:cb,cg,cl",
  "exchange_rate_source_count": 3,
  "exchange_rate_observed_at": "2026-07-17T13:00:00+00:00",
  "exchange_rate_discrepancy_bps": 12,
  "confirmations": 0,
  "confirmations_required": 12,
  "order_ref": "order_1042",
  "checkout_url": "https://cryptopayin.com/i/P-9F27C1E4KD",
  "expires_at": "2026-07-17T13:30:00+00:00",
  "created_at": "2026-07-17T13:00:00+00:00",
  "completed_at": null
}

curl https://cryptopayin.com/v1/assets \
  --header "Authorization: Bearer $CPI_SECRET_KEY"

{
  "object": "list",
  "data": [{
    "asset": "USDT",
    "network": "TRC20",
    "type": "token",
    "decimals": 6,
    "minimum_amount": 1,
    "currency": "USD",
    "base_confirmations": 19,
    "available": true,
    "rate_usd": "1.00000000",
    "rate_source": "median:cb,cg,cl",
    "rate_source_count": 3,
    "rate_discrepancy_bps": 4,
    "rate_status": "healthy",
    "rate_updated_at": "2026-07-17T13:00:00+00:00"
  }]
}

curl https://cryptopayin.com/v1/currencies \
  --header "Authorization: Bearer $CPI_SECRET_KEY"

{
  "object": "list",
  "accounting_currency": "USD",
  "data": [{
    "currency": "EUR",
    "name": "Euro",
    "symbol": "€",
    "minor_units": 2,
    "available": true,
    "minimum_amount": "0.86",
    "rate_usd": "1.160000000000",
    "rate_source": "coinbase+ecb",
    "rate_source_count": 2,
    "rate_discrepancy_bps": 18,
    "rate_updated_at": "2026-07-17T13:00:00+00:00",
    "rate_reference_at": "2026-07-16T00:00:00+00:00"
  }]
}

curl "https://cryptopayin.com/v1/payments?status=completed&limit=20" \
  --header "Authorization: Bearer $CPI_SECRET_KEY"

{
  "object": "list",
  "data": [{
    "id": "P-9F27C1E4KD",
    "object": "payment",
    "status": "completed",
    "amount": 49.99,
    "currency": "USD",
    "asset": "ETH",
    "network": "mainnet",
    "crypto_amount": "0.01388612",
    "crypto_received": "0.01388612",
    "order_ref": "order_1042",
    "confirmations": 12,
    "confirmations_required": 12,
    "completed_at": "2026-07-17T13:12:42+00:00"
  }],
  "has_more": true,
  "next_cursor": "P-9F27C1E4KD"
}

curl https://cryptopayin.com/v1/payments/P-9F27C1E4KD \
  --header "Authorization: Bearer $CPI_SECRET_KEY"

import crypto from "node:crypto";

const timestamp = req.headers["x-cpi-timestamp"];
const signature = req.headers["x-cpi-signature"];
const rawBody = req.rawBody; // Buffer captured before JSON parsing

if (Math.abs(Date.now() / 1000 - Number(timestamp)) > 300) {
  throw new Error("stale webhook");
}
const expected = "sha256=" + crypto
  .createHmac("sha256", process.env.CPI_WEBHOOK_SECRET)
  .update(Buffer.concat([Buffer.from(`${timestamp}.`), rawBody]))
  .digest("hex");
const valid = crypto.timingSafeEqual(Buffer.from(expected), Buffer.from(signature));
if (!valid) throw new Error("invalid webhook signature");

$rawBody = file_get_contents('php://input');
$timestamp = $_SERVER['HTTP_X_CPI_TIMESTAMP'] ?? '';
$received = $_SERVER['HTTP_X_CPI_SIGNATURE'] ?? '';

if (!ctype_digit($timestamp) || abs(time() - (int)$timestamp) > 300) {
    http_response_code(400); exit('stale webhook');
}
$expected = 'sha256=' . hash_hmac(
    'sha256', $timestamp . '.' . $rawBody, getenv('CPI_WEBHOOK_SECRET')
);
if (!hash_equals($expected, $received)) {
    http_response_code(401); exit('invalid signature');
}
$event = json_decode($rawBody, true, flags: JSON_THROW_ON_ERROR);

import hashlib, hmac, os, time

raw_body = request.get_data()  # bytes, before JSON decoding
timestamp = request.headers.get("X-CPI-Timestamp", "")
received = request.headers.get("X-CPI-Signature", "")
if not timestamp.isdigit() or abs(time.time() - int(timestamp)) > 300:
    raise ValueError("stale webhook")
signed = timestamp.encode() + b"." + raw_body
expected = "sha256=" + hmac.new(
    os.environ["CPI_WEBHOOK_SECRET"].encode(), signed, hashlib.sha256
).hexdigest()
if not hmac.compare_digest(expected, received):
    raise ValueError("invalid signature")

{
  "event_id": "evt_a12b34c56d78e90f12345678",
  "event": "payment.completed",
  "id": "P-9F27C1E4KD",
  "status": "completed",
  "order_ref": "order_1042",
  "amount": 49.99,
  "amount_decimal": "49.99",
  "amount_minor": 4999,
  "currency_minor_units": 2,
  "currency": "USD",
  "amount_usd": 49.99,
  "amount_usd_cents": 4999,
  "fx_rate_usd": "1.000000000000",
  "fx_source": "fixed:USD",
  "fx_observed_at": "2026-07-17T13:00:00Z",
  "fx_discrepancy_bps": 0,
  "exchange_rate": "3600.00000000",
  "exchange_rate_currency": "USD",
  "exchange_rate_source": "median:cb,cg,cl",
  "exchange_rate_source_count": 3,
  "exchange_rate_observed_at": "2026-07-17T13:00:00Z",
  "exchange_rate_discrepancy_bps": 12,
  "asset": "ETH",
  "network": "mainnet",
  "crypto_amount": "0.01388612",
  "crypto_received": "0.01388612",
  "txid": "0x9d81...75af",
  "confirmations": 12,
  "confirmations_required": 12,
  "deposit_address": "0x71b8c3d4700000000000000000000000000084e2",
  "sent_at": "2026-07-17T13:12:42Z"
}

{
  "event_id": "evt_b98c76d54e32a10f87654321",
  "event": "payout.sent",
  "id": "W-8J2K7M4RQP",
  "status": "sent",
  "asset": "ETH",
  "network": "mainnet",
  "amount": "0.25",
  "fee": "0.00081768",
  "address": "0x84f2...9bc1",
  "txid": "0xa1c4...07ee",
  "confirmations": 0,
  "note": "weekly treasury",
  "sent_at": "2026-07-17T14:08:31Z"
}

{
  "error": {
    "type": "ambiguous_asset",
    "message": "specify network (e.g. USDT.ERC20 or USDT.TRC20)",
    "request_id": "b942e21f8dca4b06b8672eb9"
  }
}