Under the hood
Streamed tool results for the Task tool can now include an agent ID and duration
What
When tool-result events are streamed through the SDK for the Task tool (used to launch subagents) and one other tool, they can now be enriched with an agentId (looked up via a new mapper) and a durationMs value pulled from the tool result, when those are present.
Why
This lets SDK consumers see which agent produced a streamed result and how long it took, useful for tracking subagent work as it streams in.
Names in the bundleagentIddurationMs
Documented inclaude-code/agent-sdk/python