Counterparty agreement checklist

The standard leaves a number of points to agreement between the parties, usually recorded in the target operating model (TOM) or service level agreement. Agree these before go-live:

Messages and versions

• Which messages are exchanged, in which direction, for which schemes (SPR / FPR / collective payout phase)
• Supported releases and the cut-over date for each new release

Size and chunking

• Maximum message size (the standard’s default is 4 MB; 10 MB is commonly agreed), and whether it is measured in MB (1,000,000 bytes) or MiB (1,048,576 bytes), compressed or uncompressed
• Maximum number of chunks, if any, and how long to wait for missing chunks
• Conventions for chunk fragment paths

Feedback

• Synchronous only, or 202 plus asynchronous callback
• Callback endpoint and expected response times
• Manual escalation channel for the panic scenarios

Security

• Mutual TLS certificates and their renewal
• OAuth 2.0 token endpoint, client credentials and scopes; API key
• Whether payloads are signed (x-jws-signature) and key management

Timing and content

• Cycle timings (for example T-4 for orders, T+3 for confirmations, month-end for definitive values)
• Service window
• Empty cohorts: include with value 0, or omit
• Any additional limits on field lengths or decimals
• Test environments and use of testMessage

Based on the VB-PUO manual §2, §4 and §7. Bron: SIVI – VB-PUO Standaard.