Identifies who performed a write or redact operation. Captured at write time on the memory_version row. The API key that created a session is not recorded on agent writes; attribution answers who made the write, not who is ultimately responsible. Look up session provenance separately via the Sessions API.
A memory_version object: one immutable, attributed row in a memory's append-only history. Every non-no-op mutation to a memory produces a new version. Versions belong to the store (not the individual memory) and are not deleted with the memory; each version is retained for at least the version retention period after it was written, unless the store itself is deleted. Retrieving a redacted version returns 200 with content, path, content_size_bytes, and content_sha256 set to null; branch on redacted_at, not HTTP status.
ID of the session that performed the write (a sesn_... value). Look up the session via Retrieve a session for further provenance.