Wave Accounting and SPS Commerce integration

What moves between them

Invoices flow from Wave to SPS Commerce. When an invoice is created or updated in Wave, ml-connector wraps it in an RSX 7.7.7 envelope as an EDI 810 (invoice) document and posts it to SPS Commerce, which routes it to the configured retail trading partners. Purchase orders from retail partners arrive in SPS Commerce as EDI 850 documents, which ml-connector polls at regular intervals and creates as Wave transactions or updates Wave vendor records to keep procurement visibility. The direction is primarily Wave invoices out and SPS inbound POs; Wave does not receive AP invoices from retail partners since Wave is an accounts receivable and general accounting platform.

How ml-connector handles it

ml-connector stores Wave OAuth credentials (including refresh tokens for the 2 hour access token expiry) and SPS Commerce client credentials encrypted. For outbound invoices, it subscribes to Wave's invoice.updated and invoice.created webhooks, fetches the full invoice via GraphQL, transforms it to RSX 7.7.7 JSON envelope format with the correct EDI 810 structure and trading partner IDs, and posts to SPS Commerce. For inbound purchase orders, ml-connector polls SPS at a configurable interval (Wave has no webhook for inbound EDI), parses the RSX envelope and EDI 850 structure, and either creates a Wave transaction (crediting revenue to a contra-accounts-receivable account) or updates an existing Wave vendor record. RSX envelopes require specific metadata headers (sender, receiver, timestamp, document type code); ml-connector builds these from Wave account information and SPS partner configuration. Wave invoices cannot be patched, so updates trigger a new RSX envelope with an updated version number. SPS rate limits are not documented, so ml-connector implements exponential backoff on 429 responses and respects cursor-based pagination. Every document carries a wave:invoiceId and sps:purchaseOrderNumber for deduplication and audit trail.

A real-world example

A small wholesale business uses Wave Accounting to manage invoicing and financials. It supplies products to three major retail chains through SPS Commerce, which handles the EDI translation and partner routing. Before the integration, the fulfillment team exported Wave invoices as PDF and manually re-entered the details into the SPS Commerce portal for each retail partner, a time-consuming and error-prone task that delayed shipments and created reconciliation problems. With Wave and SPS Commerce connected, each invoice created in Wave automatically transforms to the correct EDI 810 format and routes to the retail partners in real time. Inbound purchase orders from the retailers land in SPS and flow back to Wave, creating transaction records that the accounting team can see immediately. The business eliminates manual invoice re-entry and gains real-time visibility into what's owed and what's shipped across all three retail channels.

What you can do

• •Transform Wave invoices to EDI 810 format and post them to SPS Commerce retail partners automatically on creation or update.
• •Poll SPS Commerce for inbound purchase orders (850) and map them to Wave transactions or vendor records for full procurement visibility.
• •Handle Wave OAuth token refresh and SPS Commerce client credentials authentication without interruption.
• •Wrap all outbound documents in RSX 7.7.7 JSON envelope format with correct trading partner IDs and EDI metadata.
• •Maintain a complete audit trail of every invoice and purchase order moved between Wave and SPS Commerce, with full error recovery and replay.

Questions

How does the integration handle Wave's invoice lifecycle (created, updated, sent)?

ml-connector subscribes to Wave webhooks for invoice.created and invoice.updated events. When either fires, it fetches the full invoice details via GraphQL and posts an RSX-wrapped EDI 810 to SPS Commerce. If the invoice is updated (e.g., amount or line items change), ml-connector posts a new RSX envelope with an incremented version number so retail partners see the latest state.

Can purchase orders from retail partners flow back into Wave?

Yes. ml-connector polls SPS Commerce for inbound purchase orders (850 documents). It parses the RSX envelope, extracts the order details and retail partner ID, and can either create a Wave transaction (for revenue/receivable tracking) or update an existing Wave vendor record. Since Wave does not have native purchase orders or AP, the PO data maps to transactions.

What happens if Wave or SPS Commerce credentials expire or fail?

Wave access tokens expire every 2 hours; ml-connector stores the refresh token and automatically refreshes the access token when a GraphQL call returns a 401 or before expiry. SPS client credentials do not auto-refresh but ml-connector retries with exponential backoff on auth failures and surfaces the error so the customer can rotate credentials. Every document is stored encrypted and can be replayed once credentials are restored.