Session

What is a Session

A session is one continuous run of an agent: everything from the first message to the point it ends, pauses, or is explicitly cleared. Within a session, context accumulates, the system prompt, every user message, every tool call and its result, every reply the model gave. That accumulated history is what lets a session hold state and build on earlier turns.

A session is bounded by the size of its context window. As it grows, older material either stays, gets compacted into a shorter summary, or eventually has to be dropped to make room for new work. This is why long-running work often gets split into multiple sessions with a handoff between them, rather than one session running indefinitely.

A session is not the same as a single turn, a turn is one exchange within it. It is also not permanent: closing a session or starting a fresh one does not carry context forward automatically, unless something, a memory file, a handoff note, a resumed transcript, explicitly reconnects the two.