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# Platform memory

Platform memory is the built-in memory provided by model vendors (Claude, ChatGPT, Gemini, Copilot). It is convenient but opaque: storage and eviction policies are controlled by the provider.

Typical behavior: you ask a model to remember a preference, and future sessions may include it. There is rarely an append-only log, typed schema enforcement, or deterministic replay capability.

User: "Remember I prefer morning meetings."
Model platform: stores preference internally
Operator: cannot inspect full lineage, replay state transitions, or export a deterministic log

For production agent workflows, this model typically fails key guarantees in the comparison table (versioning, replay, audit, and deterministic resolution). Compare with [retrieval memory](/retrieval-memory) and [deterministic memory](/deterministic-memory). See also [memory model comparison](/memory-vendors).