For production-ready sample code, refer to the official SDKs:

• Go SDK: https://github.com/MartianPay/martianpay-go-sample
• Java SDK: https://github.com/MartianPay/martianpay-java-sample

Webhook Event Handling

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1. Overview: What Are Webhooks?

MartianPay leverages webhooks to proactively notify merchants of payment event changes, enabling real-time updates on transaction status.

• Trigger Conditions: Key events such as payment success, failure, or refunds will trigger a webhook notification.
• Notification Method: HTTP POST requests to your specified endpoint.

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2. Webhook Request Format

• HTTP Method: POST
• Request URL Example: https://yourdomain.com/webhook_endpoint
• Headers:

Header Name	Description	Example
Content-Type	Always application/json	application/json
Martian-Pay-Signature	Signature header for authenticity verification	t=1745580845,v1=c16a830eae640a659025a5f4bf91866d...
User-Agent	Always MartianPay/1.0	MartianPay/1.0

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3. Signature Verification

Webhook authenticity is enforced using HMAC SHA-256 signatures.

3.1 Signature Calculation (Go Example)

mac := hmac.New(sha256.New, []byte(secret))
mac.Write([]byte(fmt.Sprintf("%d", timestamp)))
mac.Write([]byte("."))
mac.Write(payload)
signature := mac.Sum(nil)

• secret: Your webhook secret key (provided by MartianPay)
• timestamp: The t field in the Martian-Pay-Signature header
• payload: The raw request body (event JSON data)

3.2 Signature Header Example

Martian-Pay-Signature: t=1745580845,v1=c16a830eae640a659025a5f4bf91866ddd4be0c85619a82defad3c10af42ec89

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4. Webhook Event Data Structure

A typical webhook event payload:

{
  "id": "evt_056qw9fr9PndljykFUqSIf6t",
  "object": "event",
  "api_version": "2025-01-22",
  "created": 1745580845,
  "data": {
    "object": {...},                // Full resource object (e.g., PaymentIntent)
    "previous_attributes": null     // Only for *.updated events
  },
  "livemode": false,
  "pending_webhooks": 0,
  "type": "payment_intent.succeeded"
}

Field Reference

Field Name	Type	Description
id	string	Unique event identifier
object	string	Always event
api_version	string	API version
created	int64	Event creation timestamp (Unix seconds)
data	EventData	Event data payload
data.object	object	Full resource data (e.g., PaymentIntent, Refund)
data.previous_attributes	object	Previous data before update (for *.updated)
livemode	bool	true for production, false for test
pending_webhooks	int64	Number of undelivered webhooks
type	string	Event type (see below)

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5. Supported Event Types

5.1 Payment Intent Events

Event Type	Description
payment_intent.created	New payment intent is created
payment_intent.succeeded	Payment intent has been fully paid and completed successfully
payment_intent.payment_failed	Payment attempt for a payment intent fails
payment_intent.processing	Payment intent is being processed (e.g., waiting for blockchain confirmation)
payment_intent.partially_paid	Payment intent has received partial payment but is not yet fully paid
payment_intent.canceled	Payment intent is canceled

5.2 Refund Events

Event Type	Description
refund.created	New refund is created
refund.succeeded	Refund has been successfully processed and funds returned to customer
refund.updated	Refund's details are updated
refund.failed	Refund attempt fails

5.3 Payout Events

Event Type	Description
payout.created	New payout is created
payout.succeeded	Payout has been successfully transferred to the recipient
payout.updated	Payout's details are updated
payout.failed	Payout attempt fails

5.4 Payroll Events

Event Type	Description
payroll.created	New payroll batch is created
payroll.approved	Payroll batch has been approved for execution
payroll.rejected	Payroll batch approval is rejected
payroll.canceled	Payroll batch is canceled
payroll.executing	Payroll batch execution has started
payroll.completed	All items in a payroll batch have been processed successfully
payroll.failed	Payroll batch execution fails

5.5 Payroll Item Events

Event Type	Description
payroll_item.processing	Individual payroll item is being processed
payroll_item.succeeded	Individual payroll item has been successfully paid
payroll_item.failed	Individual payroll item payment fails
payroll_item.address_verification_sent	Address verification email has been sent to the recipient
payroll_item.address_verified	Recipient has verified their wallet address

5.6 Subscription Events

Event Type	Description
subscription.created	New subscription is created
subscription.updated	Subscription's details are updated (e.g., plan, quantity, billing cycle)
subscription.deleted	Subscription is deleted or permanently canceled
subscription.paused	Subscription is temporarily paused
subscription.resumed	Paused subscription is resumed
subscription.trial_will_end	Subscription's trial period is about to end (typically 3 days before)

5.7 Invoice Events

Event Type	Description
invoice.created	New invoice is created (draft state)
invoice.finalized	Invoice is finalized and ready for payment
invoice.paid	Invoice has been fully paid
invoice.payment_succeeded	Payment attempt for an invoice succeeds
invoice.payment_failed	Payment attempt for an invoice fails
invoice.payment_action_required	Invoice payment requires additional action from the customer
invoice.upcoming	Upcoming invoice will be generated soon (for subscriptions)
invoice.updated	Invoice's details are updated
invoice.voided	Invoice is voided and can no longer be paid

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6. Reference Implementation

For production-ready sample code, refer to the official SDKs:

• Go SDK: https://github.com/MartianPay/martianpay-go-sample
• Java SDK: https://github.com/MartianPay/martianpay-java-sample