Thread details: see and stop the commands an agent left running (dev servers, watchers)

[OrbitMPGH]

Problem

When an agent starts something in the background, such as a dev server, a watcher or a long test run, it's hard to keep track of afterwards:

• The only sign is the background work line above the composer. Thread details, where I look for everything else about a thread, doesn't list it.
• The line's Details dialog shows the command but not its output, so I can't tell whether my server started, crashed or is waiting on something.
• Stop ends all of the agent's background work at once. With a backend and a frontend running, I can't stop just one.
• When the command writes its output to a log file (> dev.log 2>&1, which agents do a lot), there's nothing to see anywhere in T3 Code.
• On Windows, Claude commands don't stream any live output, because Claude's task output files are looked for in the POSIX temp location.

Example: I asked Claude to start the backend (.NET API) and frontend (Vite) of another project. It started both in the background, and the only way to see whether they came up was to ask the agent or find the log files myself.

Proposal

A Running section in thread details, on by default and toggled from the existing "Show in thread details" menu:

• Agent commands the agent left running in the background. Clicking one expands it in place to show the command that started it and its live output.
  • If the command writes its output to a file, that file is followed and named ("Following dev.log").
  • Each command has its own Stop, which ends only that command.
• Terminals in the thread with a running process. Clicking opens the terminal, and Stop sends Ctrl+C.

A command the agent left running, listed under Running. The arrow opens it.

Expanded: the command, the log file it writes to (wsl-app.log), and that file's live output.

Two dev servers Claude started. The Vite one is expanded with its output, and its own Stop shows on hover.

Notes on how it behaves:

• Cheap: output is only read while a row is expanded, so a chatty dev server costs nothing when nobody is looking.
• Narrow: the server only reads a file named in a command the agent ran in that thread, and only while that command is running.
• Older servers: a client connected to an older server keeps today's behavior.
• Claude only for now: it's the only provider that reports background tasks to T3 Code today. Others could follow if they report their background work.
• Web and desktop: mobile isn't included in this first version.

Implementation

I have a working version as a draft PR: #34592. It adds two RPCs (stop one background task, and subscribe to its output), Claude adapter support using the SDK's stop_task, and the Running section. It also fixes Claude's output location on Windows.

Questions for maintainers

1. Is thread details the right home, or would you rather have this on the background work line / command rows (as in See a running agent command in full: command line, live output, exit status (incl. the waiting strip) #33301), or both?
2. Should agent-started servers on Windows also show up under Servers with their port? Today the port scan can't tell which thread started them on Windows, so they only appear here as running commands. (fix(web): show running servers on thread rows #24606 attributes servers by process ancestry but also skips Windows.)

Related

• See a running agent command in full: command line, live output, exit status (incl. the waiting strip) #33301: see a running agent command in full, with live output and a per-command Stop
• Open Terminal from an agent command: agent-owned tabs grouped by thread / lineage #30557: open an agent's command in a terminal
• While a turn runs and after it ends: honest timing, running commands you can watch, and a count of what's still running #32436: running commands you can watch, and one place to stop them
• Show a background task's progress in the waiting strip while an agent waits on it #31460: a background task's progress in the waiting strip
• Show the run status and port of a project action that starts a dev server in thread details #33167: a project action's dev server status in thread details
• fix(web): show running servers on thread rows #24606: show servers that agents start on thread rows (draft)

Environment

Windows desktop app, Claude provider.