Wave Accounting and Walmart Marketplace integration

What moves between them

Orders and refunds flow from Walmart Marketplace into Wave Accounting. When a customer purchases through Walmart Marketplace, ml-connector receives the order webhook, creates an invoice in Wave with the order line items and totals, and posts it as a transaction in Wave's sales account. When a return is approved and refunded on Marketplace, ml-connector creates a corresponding credit memo in Wave. Separately, Walmart's daily reconciliation reports are polled and posted into Wave's general ledger to record settlement amounts and fees. Reference data such as items and inventory is read from Marketplace to map SKUs to Wave products.

How ml-connector handles it

ml-connector stores both credential sets encrypted and bridges the two OAuth 2.0 flows: Wave's authorization code flow requires a user login step and produces a refresh token for long-lived access, while Walmart Marketplace uses client credentials that require re-authentication every 15 minutes. ml-connector caches the Marketplace access token and refreshes it before expiry to avoid rate-limit errors on live order processing. On the Wave side, all order and refund records are created as complete invoice objects; there is no patch operation, so changes to an order after initial sync require creating an amended invoice or credit memo. Walmart's webhook signature validation uses HMAC-SHA256 and a 5-minute replay window. Marketplace rate limits single-item price updates to 100 per hour, so bulk price updates use asynchronous feed uploads instead. ml-connector maps Walmart order statuses to Wave invoice states and tracks settlement reports to post payout transactions on the Wave general ledger.

A real-world example

A small online retail business sells inventory on Walmart Marketplace as their primary sales channel, currently 50 to 150 orders per day. Before the integration, the owner manually downloaded orders from Walmart daily, entered them into Wave as invoices, and waited 2 to 3 days for settlement reports before posting payouts. With Wave Accounting and Walmart Marketplace connected, each order webhook creates an invoice in Wave immediately upon purchase, reconciliation reports flow in automatically, and settlement amounts post into the general ledger without any manual data entry. The owner now sees accurate sales and payout records in Wave within minutes instead of days, and month-end close includes real-time revenue data from the marketplace.

What you can do

• •Create Wave invoices and credit memos directly from Walmart Marketplace order and refund webhooks.
• •Post Walmart settlement reports as transactions in Wave's general ledger to record payout amounts and fees.
• •Bridge Wave's OAuth 2.0 authorization code flow with Walmart Marketplace client credentials, with automatic token refresh every 15 minutes.
• •Map Walmart order line items to Wave product records and track order status changes as invoice updates.
• •Validate Walmart webhook signatures with HMAC-SHA256 and process events in the correct order within the 5-minute replay window.

Questions

Which direction does data move between Wave Accounting and Walmart Marketplace?

Orders and refunds flow from Walmart Marketplace into Wave Accounting as invoices and credit memos. Settlement reports from Walmart are posted as transactions in Wave's general ledger. Reference data such as product records and inventory levels are read from Marketplace to help map line items to Wave accounts and products.

How does ml-connector handle the 15-minute access token expiry on Walmart Marketplace?

ml-connector caches the access token and refreshes it proactively before expiry, so live order webhooks do not encounter authentication failures. The refresh uses the same client credentials flow and is invisible to your operations.

What happens if an order changes on Walmart Marketplace after it has been synced to Wave?

Wave invoices do not support patch operations, so ml-connector creates a new amended invoice or credit memo to reflect the change, with a clear reference to the original order. This preserves the audit trail and lets you reconcile multiple invoices to a single Marketplace order.