When you send text to an LLM API in a business context, the core privacy question is: does the provider use that text to train future model versions? For the major business APIs (OpenAI, Anthropic, Mistral), the answer is no — API calls are not used for training by default. Consumer products are different. This post covers what actually happens to your data and how to build a practical policy.
What Happens to API Calls
OpenAI API
Data sent to the OpenAI API (not ChatGPT consumer) is not used to train models by default. OpenAI's usage policy for API customers distinguishes between API usage and consumer product usage. API calls may be retained for up to 30 days for safety monitoring and abuse detection, after which they are deleted.
OpenAI offers a zero data retention option for enterprise customers. Under this arrangement, inputs and outputs are not stored after the API call completes. This satisfies stricter compliance requirements for regulated industries.
Consumer ChatGPT (the web and mobile product) has different data practices. Conversations can be used for training unless users opt out in settings. If your team is using consumer ChatGPT rather than the API, the data practices are different from the API.
Anthropic API
Anthropic does not train on Claude API inputs and outputs by default. API calls may be retained for a short period for trust and safety review, with deletion after that window.
Anthropic's Claude.ai consumer product has separate terms. Users can disable conversation history in settings, which prevents that data from being used for training.
Mistral API
Mistral follows a similar pattern. API calls are not used for training. Mistral is a European company subject to GDPR, which provides additional legal constraints on data use.
Google (Gemini API via Vertex AI)
Data processed through Google Cloud Vertex AI (the enterprise API path) is not used to train models. Data processed through the consumer Google AI Studio interface may be treated differently.
What "Zero Data Retention" Means and When You Need It
Zero data retention (ZDR) means the provider does not store your inputs or outputs after the API response is returned. Standard API retention (where data is kept for 30 days for safety monitoring) is acceptable for most use cases. ZDR is appropriate when:
- Your compliance requirements prohibit any third-party retention of specific data types (PHI under HIPAA, classified information, certain financial data under SEC regulations)
- Your contracts with clients prohibit sharing their confidential information with any subprocessor
- You are processing information subject to attorney-client privilege
ZDR is available from OpenAI as an enterprise feature and from some other providers on custom enterprise agreements. If ZDR is a requirement, confirm it explicitly in your vendor contract — do not assume it applies based on general policy language.