Zero-retention is a configuration mode (offered by Anthropic, OpenAI, and Azure OpenAI under various names) in which prompts and responses are not retained beyond the request lifecycle. Specifically: prompts aren't logged for abuse review beyond a short rolling window, responses aren't cached, and neither is used for model training.
Zero-retention is typically required by compliance-conscious enterprises (legal, healthcare, financial services) and is increasingly the default for SOC 2 Type II audited AI workflows. It pairs naturally with BYOK to give customers maximum control over their data trail.