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In a nutshell
Every deposit, withdrawal, swap, or sweep that flows through Blockradar creates a transaction record. The Transactions API is your activity log — use it to fetch history, investigate specific payments, trigger missed webhooks, cancel pending transactions, or retry failed ones.

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Prerequisites

1

API Key

Get your API key from the Blockradar Dashboard. Navigate to Developers to generate one.
2

Wallet Created

You’ll need a walletId to query transactions. Create one via the dashboard or API.

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How It Works

When any on-chain event occurs on a Blockradar wallet: a deposit arriving, a withdrawal being submitted, a sweep being triggered, Blockradar creates a transaction record and fires a webhook. The Transactions API gives you programmatic access to all of these records.

Fetch History

Retrieve all transactions for a wallet or filter by address, asset, status, or date range.

Investigate Payments

Look up a specific transaction by ID to check its status, hash, and metadata.

Replay Webhooks

Resend a webhook for a transaction your system may have missed or failed to process.

Cancel or Retry

Cancel a stuck pending transaction or retry a failed one without re-submitting from scratch.

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Transaction States

StatusDescription
PENDINGTransaction submitted to the blockchain, awaiting confirmation
SUCCESSTransaction confirmed and settled
FAILEDTransaction failed on-chain or was rejected
CANCELLEDTransaction was cancelled before it was broadcast

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Fetching Transactions

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Get all transactions for a wallet

GET /v1/wallets/{walletId}/transactions
You can filter by address, asset, type, status, and date range using query parameters.

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Get a single transaction

GET /v1/wallets/{walletId}/transactions/{transactionId}

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Example

const transactions = await fetch(
  `https://api.blockradar.co/v1/wallets/${walletId}/transactions?status=SUCCESS&limit=50`,
  {
    headers: { 'x-api-key': apiKey }
  }
).then(r => r.json());

console.log(transactions.data);

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Replaying a Missed Webhook

If your system missed or failed to process a webhook, you can trigger a resend without waiting for another on-chain event. 
POST /v1/wallets/{walletId}/transactions/{transactionId}/resend-webhook
This is useful for reconciliation flows and recovering from downtime.

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Cancelling a Pending Transaction

If a transaction is stuck in PENDING and hasn’t been broadcast yet, you can cancel it. 
POST /v1/wallets/{walletId}/transactions/{transactionId}/cancel
Cancellation is only possible before a transaction is broadcast to the blockchain. Once it’s on-chain, it cannot be cancelled.

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Retrying a Failed Transaction

If a transaction failed due to insufficient gas or a temporary node issue, you can retry it. 
POST /v1/wallets/{walletId}/transactions/{transactionId}/retry

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Best Practices

  • Use webhooks as your primary signal — don’t poll the Transactions API for real-time updates. Use it for reconciliation, investigations, and history.
  • Store transaction IDs — save the Blockradar transaction ID alongside your internal records so you can look up status at any time.
  • Replay webhooks after downtime — if your webhook endpoint was unavailable, use the resend endpoint to recover missed events rather than re-processing manually.

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API Reference

EndpointDescription
Get TransactionsFetch all transactions for a wallet
Get TransactionFetch a single transaction by ID
Resend WebhookReplay a webhook for a transaction
Trigger Asset SweepManually trigger a sweep
Cancel TransactionCancel a pending transaction
Retry TransactionRetry a failed transaction