SAP ECC and AvidXchange integration

What moves between them

Vendor master records (name, address, payment terms) and GL account mappings flow from SAP ECC to AvidXchange on a daily or weekly schedule, populating the vendor and GL dimension lists in AvidXchange so approvers code invoices to the right accounts. Once invoices are approved and payments are executed in AvidXchange, ml-connector reads the payment records and GL account details and posts them into SAP ECC's general ledger via BAPI_ACC_DOCUMENT_POST, allocated to the correct cost centers. Open purchase orders can also sync to AvidXchange to enable three-way matching on receipt.

How ml-connector handles it

ml-connector runs the on-premises SAP .NET Connector or Java Connector agent on the customer network to originate RFC calls directly to SAP ECC; no cloud proxy required. It polls SAP ECC vendor and GL account tables on your schedule, transforms them into AvidXchange vendor and GL master data, and pushes them via the AvidConnect REST API using the client credentials you provide. On the return path, ml-connector reads AvidXchange payment records on a schedule, maps them to the correct SAP ECC GL accounts and cost centers, constructs a BAPI_ACC_DOCUMENT_POST payload, and commits the transaction explicitly so the posting is not left in locked state. RFC calls are retried on SYSTEM_FAILURE or COMMUNICATION_FAILURE exceptions with exponential backoff, and every record carries a full audit trail so a failed downstream call can be replayed. Because BAPI_ACC_DOCUMENT_POST has no built-in idempotency key, ml-connector uses the REF_DOC_NO field to detect duplicates on retry so the same payment is never posted twice.

A real-world example

A mid-market manufacturer runs SAP ECC on-premises for procurement, finance, and GL postings, and wants to modernize AP by adopting AvidXchange for invoice receipt, approval workflow, and payment execution. Before the integration, the AP team received AvidXchange payment reports each week, manually re-entered the GL account and cost center for each payment into SAP ECC, and spent 4 to 6 hours per cycle in data entry and reconciliation. With SAP ECC and AvidXchange connected, vendor master and GL accounts sync automatically to AvidXchange so approvers code invoices to valid accounts from day one, and completed payment GL postings flow back into SAP ECC without manual re-entry. The AP team spends the week on approval workflow and exception handling instead of at a spreadsheet.

What you can do

• •Sync vendor master records from SAP ECC to AvidXchange so all invoices are coded against current vendors and payment terms.
• •Push GL account and cost center mappings to AvidXchange to enable three-way matching and proper invoice coding.
• •Read completed payments and GL postings from AvidXchange and post them into SAP ECC using BAPI_ACC_DOCUMENT_POST with explicit transaction commit.
• •Detect and skip duplicate payments on retry by using the SAP ECC REF_DOC_NO field to prevent re-posting the same transaction.
• •Run on-premises RFC agent routing and poll on a schedule tied to your AP cycle, with full audit trail and error replay capability.

Questions

Does ml-connector require an on-premises agent for SAP ECC?

Yes. SAP ECC is on-premises and exposes data through RFC/BAPI, which cannot be called from the cloud without an agent running on your network. ml-connector uses the SAP .NET Connector or Java Connector, which must be installed on a server with network access to your SAP ECC instance. OData calls via SAP Gateway can flow over HTTP but still require the gateway to be activated by your SAP Basis team.

How does ml-connector prevent duplicate payments when retrying after a failure?

BAPI_ACC_DOCUMENT_POST lacks a built-in idempotency key, so ml-connector uses the REF_DOC_NO field to detect when the same payment has already been posted. On a retry, ml-connector checks for an existing posting with the same reference document number and skips posting if it is found, so the same GL entry is never created twice.

Can AvidXchange push invoice updates back to SAP ECC as they are approved?

AvidXchange does not expose a confirmed webhook or push-notification API, so ml-connector uses scheduled polling to read invoice status and completed payments from AvidXchange on your AP cycle (daily, weekly, or on-demand). This prevents missed updates and gives you full control over the sync cadence independent of AvidXchange events.