T3 Code adds cross-provider delegation and native subagents
One pull request brings child threads, mid-thread model switching and an ACP registry for Devin, Cline, Kimi and Droid.
Theo shipped a T3 Code release built around `delegate_task`, which lets an agent start child agents on any provider or model. Native subagents now appear as child threads in a lineage view, each showing its model, status and history, so a run is a tree rather than a single transcript.
`delegate_task` lets an agent start child agents on any provider or model
The same pull request adds an ACP registry, meaning you can add any registry agent, with Devin, Cline, Kimi and Droid named as examples. Cursor now runs on the official Cursor SDK rather than what Theo calls the broken CLI, and there is support for OpenCode 2 and for Pi.
What else is in the PR
The list Theo posted runs long. Threads can be forked. You can switch provider or model in the middle of a thread. There is auto-resume when limits reset, proper server-side queueing and steering, and scheduled tasks. A T3 Code MCP exposes tools to create, launch, message, wait on, read, search and interrupt threads, with further MCP tools for worktree handoff and for listing and closing previews. Agents themselves can rename threads, regenerate titles, link PRs and settle threads. You attach an existing thread as context by typing `@` with its name or dragging it in from the sidebar.
Theo flagged the obvious caveat himself. He wrote that there will be a lot of cleanup to do to get it perfect and to expect lots of updates over the following days. There are no benchmarks or usage numbers attached to the release, so how well delegation holds up across providers in practice is not something the post answers.
For working engineers
The direction is orchestration rather than chat. Once an agent can spawn children on a different provider, a model choice stops being a session-level setting and becomes a per-task one, which is what mid-thread switching and the lineage view are there to make visible. That fits where this harness has been heading, with Theo earlier adding a way to hide running threads and saying 18 at once stopped feeling crowded. Whether managing a tree of agents beats managing one good one is still an open question in the sources.