Transaction Lifecycle

Understanding the transaction lifecycle helps you build robust payment flows, handle edge cases, and provide accurate status updates to your customers.

Transaction States

Transactions progress through several states from creation to completion:

PENDING → PROCESSING → COMPLETED
                    ↓
                  FAILED

Status Descriptions

Status	Description	Next State	Actions Available
PENDING	Transaction created, awaiting processing	PROCESSING, FAILED	Monitor status
PROCESSING	Payment being routed and settled	COMPLETED, FAILED	Monitor status
COMPLETED	Successfully delivered to recipient	Terminal	None (final state)
FAILED	Transaction failed, funds refunded if applicable	Terminal	Create new transaction
REJECTED	Rejected by recipient or compliance	Terminal	None (final state)
REFUNDED	Completed transaction later refunded	Terminal	None (final state)
EXPIRED	Quote or payment expired before execution	Terminal	Create new quote

Terminal statuses: COMPLETED, REJECTED, FAILED, REFUNDED, EXPIREDOnce a transaction reaches a terminal status, it will not change further.

Outgoing Transaction Flow

Your customer/platform sends funds to an external recipient.

Step-by-Step

Create Quote

Lock in exchange rate and fees:

POST /quotes

{
  "source": {"accountId": "InternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965"},s
  "destination": {"accountId": "ExternalAccount:a12dcbd6-dced-4ec4-b756-3c3a9ea3d123", "currency": "EUR"},
  "lockedCurrencySide": "SENDING",
  "lockedCurrencyAmount": 100000
}

Response:

Quote ID
Locked exchange rate
Expiration time (1-5 minutes)

Execute Quote

Initiate the payment:

POST /quotes/{quoteId}/execute

Result:

Transaction created with status PENDING
Source account debited immediately
OUTGOING_PAYMENT webhook sent

Processing

Grid handles:

Currency conversion (if applicable)
Routing to appropriate payment rail
Settlement with destination bank/wallet

Status: PROCESSINGWebhook: OUTGOING_PAYMENT with updated status

Completion or Failure

Success Path:

Funds delivered to recipient
Status: COMPLETED
settledAt timestamp populated
Final OUTGOING_PAYMENT webhook sent

Failure Path:

Delivery failed (invalid account, etc.)
Status: FAILED
failureReason populated
Funds automatically refunded to source account
Final OUTGOING_PAYMENT webhook sent

Most transactions on Grid are completed in seconds.

Webhook Payloads

On Creation (PENDING):

{
  "type": "OUTGOING_PAYMENT",
  "transaction": {
    "id": "Transaction:...",
    "status": "PENDING",
    "type": "OUTGOING",
    "sentAmount": {"amount": 100000, "currency": {"code": "USD"}},
    "receivedAmount": {"amount": 92000, "currency": {"code": "EUR"}},
    "createdAt": "2025-10-03T15:00:00Z"
  }
}

On Completion:

{
  "type": "OUTGOING_PAYMENT",
  "transaction": {
    "id": "Transaction:...",
    "status": "COMPLETED",
    "settledAt": "2025-10-03T15:05:00Z"
  }
}

On Failure:

{
  "type": "OUTGOING_PAYMENT",
  "transaction": {
    "id": "Transaction:...",
    "status": "FAILED",
    "failureReason": "INVALID_BANK_ACCOUNT"
  }
}

Same-Currency Transfers

For same-currency transfers without quotes:

Transfer-Out (Internal → External)

POST /transfer-out

{
  "source": {"accountId": "InternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965"},
  "destination": {"accountId": "ExternalAccount:a12dcbd6-dced-4ec4-b756-3c3a9ea3d123", "currency": "USD"},
  "amount": 100000
}

Response:

{
  "id": "Transaction:...",
  "status": "PENDING",
  "type": "OUTGOING"
}

Follows same lifecycle as quote-based outgoing transactions.

Transfer-In (External → Internal)

POST /transfer-in

{
  "source": {"accountId": "ExternalAccount:a12dcbd6-dced-4ec4-b756-3c3a9ea3d123", "currency": "USD"},
  "destination": {"accountId": "InternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965"},
  "amount": 100000
}

Only works for “pullable” external accounts (Plaid-linked, debit cards, etc.).

Monitoring Transactions

Via Webhooks (Recommended)

Subscribe to transaction webhooks for real-time updates:

app.post('/webhooks/grid', async (req, res) => {
  const {transaction, type} = req.body;

  if (type === 'OUTGOING_PAYMENT') {
    await updateTransactionStatus(transaction.id, transaction.status);

    if (transaction.status === 'COMPLETED') {
      await notifyCustomer(transaction.customerId, 'Payment delivered!');
    } else if (transaction.status === 'FAILED') {
      await notifyCustomer(transaction.customerId, `Payment failed: ${transaction.failureReason}`);
    }
  }

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

Via Polling (Backup)

Query transaction status periodically:

GET /transactions/{transactionId}

Response:

{
  "id": "Transaction:...",
  "status": "PROCESSING",
  "createdAt": "2025-10-03T15:00:00Z",
  "updatedAt": "2025-10-03T15:02:00Z"
}

Poll every 5-10 seconds until terminal status reached.

Listing Transactions

Query all transactions for a customer or date range:

GET /transactions?customerId=Customer:abc123&startDate=2025-10-01T00:00:00Z&limit=50

Response:

{
  "data": [
    {
      "id": "Transaction:...",
      "status": "COMPLETED",
      "type": "OUTGOING",
      "sentAmount": {"amount": 100000, "currency": {"code": "USD"}},
      "receivedAmount": {"amount": 92000, "currency": {"code": "EUR"}},
      "settledAt": "2025-10-03T15:05:00Z"
    }
  ],
  "hasMore": false,
  "nextCursor": null
}

Use for reconciliation and reporting.

Failure Handling

Common Failure Reasons

Failure Reason	Description	Recovery
`QUOTE_EXPIRED`	Quote expired before execution	Create new quote
`QUOTE_EXECUTION_FAILED`	Error executing the quote	Create new quote
`INSUFFICIENT_BALANCE`	Source account lacks funds	Fund account, retry
`TIMEOUT`	Transaction timed out	Retry or contact support

Best Practices

Always use webhooks for status updates

Don’t rely solely on polling:

// ✅ Good: Webhook-driven updates
app.post('/webhooks/grid', async (req, res) => {
  await handleTransactionUpdate(req.body.transaction);
  res.status(200).send();
});

// ❌ Bad: Constant polling
setInterval(() => getTransaction(txId), 5000);

Store transaction IDs for reconciliation

Save transaction IDs to your database:

const transaction = await executeQuote(quoteId);
await db.transactions.insert({
  gridTransactionId: transaction.id,
  internalPaymentId: paymentId,
  status: transaction.status,
  createdAt: new Date()
});

Handle idempotency

Use idempotency keys for safe retries:

const idempotencyKey = `payment-${userId}-${Date.now()}`;
await createQuote({...params, idempotencyKey});

Provide clear status messages to users

Translate technical statuses to user-friendly messages:

function getUserMessage(status, failureReason) {
  if (status === 'PENDING') return 'Payment processing...';
  if (status === 'PROCESSING') return 'Payment in progress...';
  if (status === 'COMPLETED') return 'Payment delivered!';
  if (status === 'FAILED') {
    if (failureReason === 'INSUFFICIENT_BALANCE') {
      return 'Insufficient funds. Please add money and try again.';
    }
    return 'Payment failed. Please try again or contact support.';
  }
}

Introduction

Core Concepts

Transaction States

Status Descriptions

Outgoing Transaction Flow

Step-by-Step

Webhook Payloads

Same-Currency Transfers

Transfer-Out (Internal → External)

Transfer-In (External → Internal)

Monitoring Transactions

Via Webhooks (Recommended)

Via Polling (Backup)

Listing Transactions

Failure Handling

Common Failure Reasons

Best Practices

Introduction

Core Concepts

​Transaction States

​Status Descriptions

​Outgoing Transaction Flow

​Step-by-Step

​Webhook Payloads

​Same-Currency Transfers

​Transfer-Out (Internal → External)

​Transfer-In (External → Internal)

​Monitoring Transactions

​Via Webhooks (Recommended)

​Via Polling (Backup)

​Listing Transactions

​Failure Handling

​Common Failure Reasons

​Best Practices

Transaction States

Status Descriptions

Outgoing Transaction Flow

Step-by-Step

Webhook Payloads

Same-Currency Transfers

Transfer-Out (Internal → External)

Transfer-In (External → Internal)

Monitoring Transactions

Via Webhooks (Recommended)

Via Polling (Backup)

Listing Transactions

Failure Handling

Common Failure Reasons

Best Practices