Lag time API overview

Lag time is the number of days between when an order is placed and when the item ships. During item setup you can set lag time to 0 or 1 day. Values above 1 day require approval at the item setup category level. Download the Lag Time Exception schema package when you prepare bulk updates. Sellers can:

• Retrieve lag time for a single item. Use GET /v3/lagtime with a SKU or GTIN. Include a ship node if your catalog uses multiple nodes.
• Update lag time in bulk. Submit a feed with POST /v3/feeds?feedType=lagtime to change lag time for many items. Use the Lag Time Exception schemas.
• Validate at scale. Use feed status to confirm processing, then spot-check items with GET /v3/lagtime

Prerequisites

• A Walmart Marketplace developer account with API access.
• OAuth 2.0 flow in place to request and refresh access tokens. Include the token in WM_SEC.ACCESS_TOKEN.
• Required headers on each call: WM_QOS.CORRELATION_ID, WM_SVC.NAME. WM_CONSUMER.CHANNEL.TYPE may be required for some integrations. See the reference pages for any call-specific requirements.

Endpoints

• Retrieve lag time
  GET /v3/lagtime: returns the lag time configured for a SKU or GTIN, optionally scoped by ship node.

• Update lag time in bulk
  POST /v3/feeds?feedType=lagtime: submits a feed that updates fulfillmentLagTime for multiple items. Use the Lag Time Exception schemas.

• Check feed status
  GET /v3/feeds/{feedId}: monitors processing and provides line-level results.

How it works

Overall seller journey

1. Authenticate. Obtain an OAuth 2.0 access token and send it in WM_SEC.ACCESS_TOKEN on every request.
2. Read current values (optional). Call GET /v3/lagtime to verify the configured lag time before you change it.
3. Prepare a bulk update. Build an XML or JSON payload that follows LagTimeException.zip, then post it with feedType=lagtime.
4. Monitor processing. Track your submission with the Feeds APIs until it is processed, then review any line-level errors.

For Marketplace suppliers, the common user journey might entail a seller or solution provider to complete the following flow:

Best practices

• Keep lag time at 0 or 1 day unless you have an approved exception. This improves delivery speed and customer experience.
• After posting a bulk update, verify processing with the Feeds APIs, then validate a sample of items using GET /v3/lagtime.
• Align values with operational reality. Do not set a lag time you cannot meet.

Payloads and schemas

Bulk updates use the Lag Time Exception schemas. Download LagTimeException.zip from the reference page before constructing XML or JSON. Ensure your entries include a product identifier and a fulfillmentLagTime value in days.

Market availability

This overview applies to the U.S. Marketplace. Some rules and approval processes vary by market. If you sell outside the U.S., confirm details on the global reference page for updating lag time.

Next steps

• Lag time status (GET)
• Update lag time status (POST)
• Feeds overview
• Request lag time exceptions and reports