A full managed-agent worker runtime ships in every install but nothing in the CLI enters that flow.
What
The bundled Anthropic SDK gained a full worker runtime that polls a server for agent work and runs it locally. It is present in every install but only runs under managed-agents flows, which nothing in normal CLI use enters.
Details
- Polls, acknowledges, heartbeats and stops against
/v1/environments/{id}/work, every request sending the headeranthropic-beta: managed-agents-2026-04-01 - A session runner streams session events, executes tool calls, honours allow/deny confirmations from the user, and ends the turn after an idle status
- Ships a default toolset of
bash,read,write,edit,glob,grep, all confined to a working directory with checks that reject paths escaping it - None of these runtime pieces existed in 2.1.227
Evidence
Cannot iterate over a consumed SessionToolRunner
Strings lifted out of the shipped bundle, so the claim above can be checked against them.