Seller performance alarms

Use this webhook to receive a daily summary of shipping risks and actions for a seller. Use it to prevent auto cancellations and late delivery, and to prioritize fulfillment tasks.

Event type

  • Use the consolidatedSELLER_PERFORMANCE_NOTIFICATIONS event.
  • Route by payload.notificationType= ALARMS

Who this is for
Operations and fulfillment teams, and approved Solution Providers that coordinate order processing and shipping.

How it works

  1. Walmart evaluates orders for the prior and upcoming windows.
  2. Walmart summarizes shipping risks and actions and posts a ALARMS notification to your callback URL.
  3. Your service verifies the signature, stores the event, and creates tasks for each alarm.
  4. Your service returns 2xx after a durable write.

Timing

Sent daily at 6:00 AM PT.

Before you begin

  • A Walmart Marketplace account and API credentials
  • A public HTTPS callback URL
  • Request signature verification in your receiver (see Security and authenticity)

Delivery payload

Delivery format

Webhook requests include a payload object with event-specific fields. Use the following schema to validate and parse the payload, then return a 2xx response after a durable write.

Payload schema

{ "source": { "eventType": "SELLER_PERFORMANCE_NOTIFICATIONS", "eventTime": "2019-02-21T01:01:08.000Z", "eventId": "03d34580-61d4-11ea-9e23-cd38810ff7cd" }, "payload": { "partnerId": "123456789", "lastRefreshTs": "2025-09-10 12:52:36 UTC", "ordersApiUrl": "https://developer.walmart.com/", "moreInfoLink": "https://marketplacelearn.walmart.com/guides/Policies%20&%20standards/Performance/Performance-alarms", "supportedLanguages": [ "en-US" ], "notificationType": "ALARMS", "enNotification": { "summary": "We have identified 100 orders that need your immediate attention.", "message": "For information on all the orders, please use the following orders api", "poNumberMaxCount": 1000, "alarms": [ { "alarmType": "LateOriginScan", "orderCount": 5, "description": "We have noticed that the above shipped orders have not been scanned by the carrier within 48 hours of the shipping confirmation being sent.", "action": "We suggest you contact the carrier as needed to address the delays and verify your tracking information is valid for all your shipments.", "poNumbers": [ "123", "456" ] }, { "alarmType": "AutoCancelledYday", "orderCount": 5, "description": "We did not receive valid tracking information within 4 calendar days after the Expected Ship Date (ESD), resulting in the automatic cancellation of the above orders.", "action": "Do not ship the above order, as the customer has already been refunded.", "poNumbers": [ "123", "456" ] }, { "alarmType": "AutoCancelledWarning", "orderCount": 5, "description": "We have not yet received tracking information for the above orders.", "action": "Please upload valid tracking information today or proactively cancel the orders.", "poNumbers": [ "123", "456" ] }, { "alarmType": "ShippingDueToday", "orderCount": 5, "description": "We have not yet received tracking information for the above orders.", "action": "Please upload valid tracking information today or proactively cancel the orders.", "poNumbers": [ "123", "456" ] }, { "alarmType": "UnshippedOrders", "orderCount": 5, "description": "We have not yet received tracking information for the above orders.", "action": "Please upload valid tracking information today or proactively cancel the orders.", "poNumbers": [ "123", "456" ] } ] } }
}

Field notes

  • ordersApiUrl helps developers link to order-level details for investigation and remediation.
  • moreInfoLink points to guidance on performance alarms.
  • enNotification.alarms[] contains one element per alarm type, with an action string and a list of affected poNumbers for quick triage.

Handle the event

  1. Verify the request signature.
  2. Confirm the event targets a seller you manage.
  3. Store the payload and deduplicate using the delivery identifier exposed to integrators (for example, a top-level eventId or a documented delivery header).
  4. Create tasks or alerts based on enNotification.alarms[].
  5. Return 2xx after you finish the write.

Errors and retries

  • Walmart retries on non-2xx with backoff.
  • Repeated failures can mark your endpoint as broken and trigger email notices to your contacts.
  • Monitor delivery logs and fix broken endpoints before you re-enable them. See Troubleshooting and delivery health.

Test in sandbox

Use the test delivery endpoint to send a sample event to your callback URL. Start with the sample payload and adjust alarm types to validate your flows.
How-to: Test in sandbox
API reference: Test notification

Next steps

Reference guide

  • Get event types: Lists available performance events and versions.
  • Create subscription: Registers your callback URL for a unified endpoint that includes ALARMS variant.
  • Update subscription: Changes an existing subscription to route this event to a different endpoint or to adjust the event set.
  • Test notification: Triggers a sample delivery to your callback URL to validate signature checks and handling.

See also