Devin Sessions And Planning

Operator creates a Devin session via POST /v1/sessions passing snapshot_id from a prior session to resume on the same VM state.

Pass snapshot_id only when the prior session was NOT terminated — terminate is irreversible and invalidates the snapshot. On 4xx referencing an invalid snapshot, surface to operator with a 'create fresh session' fallback, do not loop the retry. Record the new session_id and persist the snapshot lin…

Operator's automation calls POST /v1/sessions/{id}/terminate as a 'pause' to stop ACU accrual.

Terminate is irreversible per docs — once terminated the session cannot be resumed and the VM snapshot is invalidated. To stop ACU accrual without destroying state, rely on idle-sleep (sessions sleep automatically) and wake by sending a message. Document this distinction in the operator's runbook.

Operator wants the new session to follow a repeatable workflow ('triage Linear bug → repro → fix → PR'). They attach a playbook at session creation.

Attach the playbook by reference (playbook id) at create time, not by inlining instructions into the first message — playbook updates then propagate to future runs. Confirm the session metadata records the playbook id so audit trails can correlate behavior to playbook version.