Purpose: passes recoverable task context between providers or humans. Schema: schemas/contracts/handoff-packet.schema.json. Required: schema_version, task_id, reason, from_provider; destination provider, checkpoint, and evidence are optional. Valid/invalid examples: examples.json#/handoff-packet.
Created after quota, provider, process, or human-decision failure; it must not contain raw secrets. The controller/Hermes produces it; the next assignee consumes it. Versioning/migration: provisional, additive changes preferred. Maturity: provisional.