BLOCKCHAIN_TRANSACTION_DETECTED
Delivered when an address covered by one of your blockchain notification subscriptions sends or receives a matching token.
Delivered to the subscription's webhookUrl, falling back to your business
webhook URL.
This payload is not wrapped in a body object — eventType sits at the
top level, alongside the transaction fields.
Payload
{
"eventType": "BLOCKCHAIN_TRANSACTION_DETECTED",
"id": "0a52d1c4-2f43-4e58-9d40-2f0c5cbb9e77",
"subscriptionId": "3f6f9d1a-64b2-4c7f-9a1e-7a2f0c8c7e11",
"address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
"type": "EVM",
"network": "MATIC_MAINNET",
"token": "USDC",
"direction": "INCOMING",
"amount": "125.50",
"rawAmount": "125500000",
"fromAddress": "0x1111111111111111111111111111111111111111",
"toAddress": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
"transactionHash": "0xb0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f70819",
"eventIndex": 3,
"blockNumber": 61234567,
"metadata": { "customerId": "cus_8121" }
}The subscription that matched. Route on this to find what you were watching for.
The watched address, as stored on the subscription.
INCOMING or OUTGOING, relative to the watched address.
The transfer amount in token units, as a decimal string.
The same amount in the token's base units.
The transfer's position within the transaction. A single transaction can
contain several transfers, so transactionHash alone is not unique.
Whatever you stored on the subscription, returned verbatim.
Deduplication
Use transactionHash and eventIndex together as the idempotency key. A
transaction that moves stablecoin more than once produces one event per
transfer, all sharing the same hash.
const key = `${payload.transactionHash}:${payload.eventIndex}`;Knit does not hold the funds these events describe. The webhook tells you money moved; acting on it — crediting a customer, releasing goods — is entirely your decision, and you should apply your own confirmation policy before treating a transfer as final.
See also
- Blockchain notifications
- Create a subscription
- Webhooks overview — signature verification and retries
