Backend-controlled message history via hydrateMessages hook — loads from
DB on every turn, replacing the linear accumulator. Imperative chat.history
API (rollbackTo, remove, replace, slice) for modifying history from any
hook or run(). Custom actions via actionSchema + onAction — typed actions
sent through transport.sendAction() that wake the agent, modify state,
then trigger run(). Adds sendAction to both TriggerChatTransport and
AgentChat.
Eric Allam
bbb5cfb033