Sending Payments

Send payments from your customers’ internal accounts to their external bank accounts or to other destinations. Grid supports both same-currency transfers and cross-currency transfers with automatic exchange rate handling.

Overview

Grid provides two payment methods depending on your use case:

Prerequisites

Before sending payments, ensure you have:

An active internal account with sufficient balance
A verified external account for the destination
Valid API credentials with appropriate permissions
A webhook endpoint configured to receive payment status updates (recommended)

If you don’t have these set up yet, review the Internal Accounts and External Accounts guides first.

Same-Currency Transfers

Use the /transfer-out endpoint when sending funds in the same currency (no exchange rate needed). This is the simplest and fastest option for domestic transfers.

When to use same-currency transfers

Transferring USD from a USD internal account to a USD external account
Sending funds within the same country using the same payment rail
No currency conversion is required

Create a transfer

Get account IDs

Retrieve the internal account (source) and external account (destination) IDs:

curl -X GET 'https://api.lightspark.com/grid/2025-10-13/customers/internal-accounts?customerId=Customer:019542f5-b3e7-1d02-0000-000000000001' \
  -H 'Authorization: Basic $GRID_CLIENT_ID:$GRID_CLIENT_SECRET'

Note the id fields from both the internal and external accounts you want to use.

Initiate the transfer

Create the transfer by specifying the source and destination accounts:

cURL

curl -X POST 'https://api.lightspark.com/grid/2025-10-13/transfer-out' \
  -H 'Authorization: Basic $GRID_CLIENT_ID:$GRID_CLIENT_SECRET' \
  -H 'Content-Type: application/json' \
  -d '{
    "source": {
      "accountId": "InternalAccount:a12dcbd6-dced-4ec4-b756-3c3a9ea3d123"
    },
    "destination": {
      "accountId": "ExternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965"
    },
    "amount": 12550
  }'

Success (201 Created)

{
  "id": "Transaction:019542f5-b3e7-1d02-0000-000000000015",
  "status": "PENDING",
  "type": "OUTGOING",
  "source": {
    "accountId": "InternalAccount:a12dcbd6-dced-4ec4-b756-3c3a9ea3d123",
    "currency": "USD"
  },
  "destination": {
    "accountId": "ExternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965",
    "currency": "USD"
  },
  "sentAmount": {
    "amount": 12550,
    "currency": {
      "code": "USD",
      "name": "United States Dollar",
      "symbol": "$",
      "decimals": 2
    }
  },
  "receivedAmount": {
    "amount": 12550,
    "currency": {
      "code": "USD",
      "name": "United States Dollar",
      "symbol": "$",
      "decimals": 2
    }
  },
  "customerId": "Customer:019542f5-b3e7-1d02-0000-000000000001",
  "platformCustomerId": "customer_12345",
  "createdAt": "2025-10-03T15:00:00Z",
  "settledAt": null
}

The amount is specified in the smallest unit of the currency (cents for USD, pence for GBP, etc.). For example, 12550 represents $125.50 USD.

Track transfer status

The transaction is created with a PENDING status and progresses through PROCESSING to COMPLETED or FAILED. Monitor the status by:You’ll receive OUTGOING_PAYMENT.<STATUS> webhooks as the transaction progresses. The webhook body contains the full transaction resource:

{
  "type": "OUTGOING_PAYMENT.COMPLETED",
  "data": {
    "id": "Transaction:019542f5-b3e7-1d02-0000-000000000015",
    "status": "COMPLETED",
    "type": "OUTGOING",
    "sentAmount": { "amount": 12550, "currency": { "code": "USD", "decimals": 2 } },
    "receivedAmount": { "amount": 12550, "currency": { "code": "USD", "decimals": 2 } },
    "settledAt": "2025-10-03T15:02:30Z"
  },
  "timestamp": "2025-10-03T15:03:00Z"
}

If a transaction fails, Grid initiates a refund automatically. You’ll receive OUTGOING_PAYMENT.REFUND_PENDING followed by OUTGOING_PAYMENT.REFUND_COMPLETED or OUTGOING_PAYMENT.REFUND_FAILED. The transaction’s refund object tracks the refund status and reference.

For the full state diagram, refund object details, and all webhook scenarios (including bank returns and manual cancellations), see the Transaction Lifecycle guide.

Transaction statuses

Status	Description
`PENDING`	Transfer initiated and awaiting processing
`EXPIRED`	Quote wasn’t executed before the expiry window
`PROCESSING`	Transfer in progress through the payment rail
`COMPLETED`	Transfer successfully completed
`FAILED`	Transfer failed — accompanied by a `failureReason`

For the full state diagram including refund tracking and edge cases like bank returns, see the Transaction Lifecycle guide.

Cross-Currency Transfers

Use the quotes flow when sending funds with currency conversion. This locks in an exchange rate and provides all details needed to execute the transfer.

When to use cross-currency transfers

Converting USD to EUR, MXN, BRL, or other supported currencies
Sending international payments with automatic currency conversion
Need to lock in a specific exchange rate for the transfer

Create and execute a quote

Create a quote

Request a quote to lock in the exchange rate and get transfer details:

cURL

curl -X POST 'https://api.lightspark.com/grid/2025-10-13/quotes' \
  -H 'Authorization: Basic $GRID_CLIENT_ID:$GRID_CLIENT_SECRET' \
  -H 'Content-Type: application/json' \
  -d '{
    "source": {
      "sourceType": "ACCOUNT",
      "accountId": "InternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965"
    },
    "destination": {
      "destinationType": "ACCOUNT",
      "accountId": "ExternalAccount:a12dcbd6-dced-4ec4-b756-3c3a9ea3d123"
    },
    "lockedCurrencySide": "SENDING",
    "lockedCurrencyAmount": 10000,
    "description": "Payment for services - Invoice #1234"
  }'

Success (201 Created)

{
  "id": "Quote:019542f5-b3e7-1d02-0000-000000000025",
  "status": "PENDING",
  "source": {
    "accountId": "InternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965",
    "currency": "USD"
  },
  "destination": {
    "accountId": "ExternalAccount:a12dcbd6-dced-4ec4-b756-3c3a9ea3d123",
    "currency": "EUR"
  },
  "sendingAmount": {
    "amount": 10000,
    "currency": {
      "code": "USD",
      "name": "United States Dollar",
      "symbol": "$",
      "decimals": 2
    }
  },
  "receivingAmount": {
    "amount": 9200,
    "currency": {
      "code": "EUR",
      "name": "Euro",
      "symbol": "€",
      "decimals": 2
    }
  },
  "exchangeRate": 0.92,
  "fee": {
    "amount": 50,
    "currency": {
      "code": "USD",
      "symbol": "$",
      "decimals": 2
    }
  },
  "expiresAt": "2025-10-03T15:15:00Z",
  "createdAt": "2025-10-03T15:00:00Z",
  "description": "Payment for services - Invoice #1234"
}

Locked currency side determines which amount is fixed:

SENDING: Lock the sending amount (receiving amount calculated based on exchange rate)
RECEIVING: Lock the receiving amount (sending amount calculated based on exchange rate)

Review quote details

Before executing, review the quote to ensure:

Exchange rate is acceptable
Fees are as expected
Receiving amount meets requirements
Quote hasn’t expired (check expiresAt)

Quote expiration depends on the corridor but is typically ~5 minutes or greater. If expired, create a new quote to get an updated exchange rate.

Execute the quote

Confirm and execute the quote to initiate the transfer:

cURL

curl -X POST 'https://api.lightspark.com/grid/2025-10-13/quotes/Quote:019542f5-b3e7-1d02-0000-000000000025/execute' \
  -H 'Authorization: Basic $GRID_CLIENT_ID:$GRID_CLIENT_SECRET'

Success (200 OK)

{
  "id": "Quote:019542f5-b3e7-1d02-0000-000000000025",
  "status": "PROCESSING",
  "transactionId": "Transaction:019542f5-b3e7-1d02-0000-000000000030",
  "source": {
    "accountId": "InternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965",
    "currency": "USD"
  },
  "destination": {
    "accountId": "ExternalAccount:a12dcbd6-dced-4ec4-b756-3c3a9ea3d123",
    "currency": "EUR"
  },
  "sendingAmount": {
    "amount": 10000,
    "currency": {
      "code": "USD",
      "symbol": "$",
      "decimals": 2
    }
  },
  "receivingAmount": {
    "amount": 9200,
    "currency": {
      "code": "EUR",
      "symbol": "€",
      "decimals": 2
    }
  },
  "exchangeRate": 0.92,
  "executedAt": "2025-10-03T15:05:00Z"
}

Once executed, the quote creates a transaction and the transfer begins processing. The transactionId can be used to track the payment.

Real-time funding sources: If your quote uses a real-time funding source (USDC, BTC, RTP, or FedNow), you don’t call the execute endpoint. Instead, send a payment to the account specified in the quote’s paymentInstructions. Grid detects the deposit and processes the transfer automatically.

Monitor completion

After execution, a transaction is created and progresses through PENDING → PROCESSING → COMPLETED or FAILED. You’ll receive OUTGOING_PAYMENT.<STATUS> webhooks as the transaction progresses:

{
  "type": "OUTGOING_PAYMENT.COMPLETED",
  "data": {
    "id": "Transaction:019542f5-b3e7-1d02-0000-000000000030",
    "status": "COMPLETED",
    "type": "OUTGOING",
    "sentAmount": {
      "amount": 10000,
      "currency": { "code": "USD", "symbol": "$", "decimals": 2 }
    },
    "receivedAmount": {
      "amount": 9200,
      "currency": { "code": "EUR", "symbol": "€", "decimals": 2 }
    },
    "exchangeRate": 0.92,
    "settledAt": "2025-10-03T15:30:00Z",
    "quoteId": "Quote:019542f5-b3e7-1d02-0000-000000000025"
  },
  "timestamp": "2025-10-03T15:31:00Z"
}

For the full state diagram, refund object details, and all webhook scenarios (including bank returns and manual cancellations), see the Transaction Lifecycle guide.

Transaction statuses

Status	Description
`PENDING`	Quote created, awaiting execution
`PROCESSING`	Quote executed, transfer in progress
`COMPLETED`	Transfer successfully completed
`FAILED`	Transfer failed — refund initiated automatically (track via `refund` object)
`EXPIRED`	Quote expired without execution

Checking Payment Status

Configure a webhook endpoint to receive real-time notifications when payment status changes:

app.post("/webhooks/grid", (req, res) => {
  const { type, data } = req.body;

  switch (type) {
    case "OUTGOING_PAYMENT.COMPLETED":
      console.log(`Payment ${data.id} completed at ${data.settledAt}`);
      // Update your database, notify customer
      break;

    case "OUTGOING_PAYMENT.FAILED":
      console.log(`Payment ${data.id} failed: ${data.failureReason}`);
      // Handle failure, notify customer — refund webhook follows
      break;

    case "OUTGOING_PAYMENT.PROCESSING":
      console.log(`Payment ${data.id} is processing`);
      // Optional: Update UI to show processing state
      break;

    case "OUTGOING_PAYMENT.REFUND_COMPLETED":
      console.log(`Payment ${data.id} refund completed`);
      // Update your records with refund details
      break;

    case "OUTGOING_PAYMENT.REFUND_FAILED":
      console.log(`Payment ${data.id} refund failed`);
      // Alert your team — may require manual resolution
      break;
  }

  res.status(200).json({ received: true });
});

See the Webhooks guide for complete webhook implementation details including signature verification.

Best Practices

Handle quote expiration gracefully

Quote expiration depends on the corridor (typically ~5 minutes or greater). Always check expiration before executing:

async function executeQuoteWithCheck(quoteId) {
  const quote = await getQuote(quoteId);

  if (new Date(quote.expiresAt) < new Date()) {
    // Quote expired, create a new one
    const newQuote = await createQuote({
      source: quote.source,
      destination: quote.destination,
      lockedCurrencySide: quote.lockedCurrencySide,
      lockedCurrencyAmount: quote.lockedCurrencyAmount,
    });

    return executeQuote(newQuote.id);
  }

  return executeQuote(quoteId);
}

Include descriptive payment references

Always include meaningful descriptions to help with reconciliation:

const description = [
  `Invoice #${invoiceId}`,
  `Customer: ${customerName}`,
  `Date: ${new Date().toISOString().split("T")[0]}`,
].join(" | ");

await createQuote({
  // ... other fields
  description: description,
});

This makes it easier to match payments in your accounting system and provides context when reviewing transactions.

Store transaction IDs in your system

Always save transaction and quote IDs for audit trails and support:

const quote = await createQuote(quoteData);

// Save to your database immediately
await db.payments.create({
  quoteId: quote.id,
  customerId: customer.id,
  amount: quote.sendingAmount.amount,
  currency: quote.sendingAmount.currency.code,
  status: "pending",
  createdAt: new Date(),
});

const execution = await executeQuote(quote.id);

// Update with transaction ID
await db.payments.update(
  { quoteId: quote.id },
  { transactionId: execution.transactionId, status: "processing" }
);

Overview

Onboarding

Managing Accounts

Platform Tools

Sending Payments

Overview

Prerequisites

Same-Currency Transfers

When to use same-currency transfers

Create a transfer

Transaction statuses

Cross-Currency Transfers

When to use cross-currency transfers

Create and execute a quote

Transaction statuses

Checking Payment Status

Best Practices

Next Steps

Overview

Onboarding

Managing Accounts

Sending Payments

Platform Tools

​Overview

​Prerequisites

​Same-Currency Transfers

​When to use same-currency transfers

​Create a transfer

​Transaction statuses

​Cross-Currency Transfers

​When to use cross-currency transfers

​Create and execute a quote

​Transaction statuses

​Checking Payment Status

​Best Practices

​Next Steps

Overview

Prerequisites

Same-Currency Transfers

When to use same-currency transfers

Create a transfer

Transaction statuses

Cross-Currency Transfers

When to use cross-currency transfers

Create and execute a quote

Transaction statuses

Checking Payment Status

Best Practices

Next Steps