- You can now set an
effort level on a Claude Managed Agents agent's model configuration. Pass effort inside the model object when you create the agent. See Effort levels for what each level does.
- Webhooks for Claude Managed Agents now cover the environment and memory store lifecycle: four
environment.* event types and three memory_store.* event types. You can react to environment and memory store lifecycle changes without polling. See the Environment events and Memory store events tabs in Subscribe to webhooks.
- When creating a Claude Managed Agents session, you can now seed it with initial events. Pass
initial_events on POST /v1/sessions with up to 50 user.message and user.define_outcome events. A non-empty list starts the agent loop in the same call, so you don't need a separate send-events request to start work.
- The
version field is now optional when updating a Claude Managed Agents agent. Supply it for optimistic concurrency (a mismatch returns a 409 error), or omit it to apply the update unconditionally. See Update semantics.
- Claude Managed Agents session thread event streams now support event deltas.
GET /v1/sessions/{session_id}/threads/{thread_id}/stream accepts the same event_deltas[] query parameter as the session-level stream, so you can preview a subagent's text as the model generates it. A connection previews only the thread it's reading. See Preview session thread events.