Webhooks

Overview

Webhooks allow your application to receive real-time HTTP notifications when events occur. Instead of polling the API, Senddy sends a POST request to your configured endpoint.

Setting up webhooks

Go to your Developer Settings
Navigate to the Webhooks section
Enter your endpoint URL (must be HTTPS)
Select the events you want to receive
Save your configuration

Event types

Event	Description
`payment.received`	A payment was received to your address
`payment.confirmed`	A payment has been confirmed on-chain
`deposit.completed`	A deposit has been shielded into the privacy pool
`withdrawal.completed`	A withdrawal has been processed
`bridge.completed`	A cross-chain bridge transfer has arrived

Webhook payload

All webhooks are delivered as HTTP POST requests with a JSON body:

{
  "id": "evt_abc123",
  "type": "payment.received",
  "timestamp": "2025-01-15T12:00:00Z",
  "data": {
    "amount": "50000000",
    "currency": "USDC",
    "memo": "Order 123"
  }
}

Verifying webhooks

Each webhook request includes a signature header for verification:

X-Senddy-Signature: sha256=...

Verify the signature using your webhook secret (available in Developer Settings) to ensure the request is authentic.

Retry policy

If your endpoint returns a non-2xx status code, Senddy will retry delivery:

1st retry: 1 minute after failure
2nd retry: 5 minutes
3rd retry: 30 minutes
4th retry: 2 hours
5th retry: 24 hours

After 5 failed attempts, the webhook is marked as failed and no further retries are attempted.

Requirements

Webhooks are available on the Developer plan ($29/mo) and above
Endpoint must accept HTTPS POST requests
Endpoint must respond within 10 seconds
Maximum payload size: 64 KB