Transferring agent context from one session to another. The carry mechanism varies — a written handoff artifact, an in-memory summary (compaction), and others. Distinct from clearing (no transfer at all). Reasons vary: switching roles (planner → implementer), kicking off an AFK run, fanning out to parallel sessions, or freeing up context window room.
The receiving session starts with zero context — the model is stateless, and nothing from the old session is visible to the new one. Whatever the next session needs has to be carried explicitly; everything else is gone. "No return path" is the constraint that shapes the carry: the new session can't ask the old one what it meant, so the carried material has to stand on its own.
| Mechanism | Form | Properties |
|---|---|---|
| Handoff artifact | File in the environment | You can read and correct it before anything depends on it; reusable across many sessions |
| Compaction | Summary in the context window | Automatic and cheap; harder to inspect; feeds one successor |
The visible failure of a bad handoff is relitigation: the new session re-opens decisions the old one had settled, because the carry recorded what was decided but not why. Judge a handoff by what a session with zero context could do with it.
Usage:
"Planning session is getting heavy — should I just keep going?"
"Do a handoff. Write the decisions to a doc, clear, start the implementation in a fresh session reading from it."