Recording exactly which model, prompt, retrieval index and code produced a given result. Four things change independently here, and without a version stamp on each, a quality change cannot be traced to its cause and results cannot be reproduced.
Technical view
Every request should log a composite version identifier covering model and provider version, prompt template version, retrieval index snapshot, tool definitions and application build. Prompt and configuration should be versioned in source control and deployed as artefacts rather than edited in place. This is the prerequisite for attribution, regression analysis, audit and any credible incident investigation.
Related
Part of AI Terminology Index, section: Running It in Production.