What a source can see of the sequence so far.
Readonly
Tokens the caller may still emit (max_tokens − generated).
Tokens seen: prompt + everything emitted (injected tokens included).
The last n ids, oldest first. Shorter near the start of a request, and bounded by the session's retained window — a source that needs more history keeps its own copy (see observe()).
n
What a source can see of the sequence so far.