Let agents use a real terminal in the thread that I can watch and type into

[iput-object]

Right now terminals in T3 are split in two. The thread terminal (Ctrl+J) is mine. The agent runs its commands somewhere else: tool cards for Codex/Claude, and plain child processes for ACP agents (packages/provider-acp/src/server/clientTerminals.ts). So I can't watch the agent's commands live in a real terminal, and I can't step in when it gets stuck.

What I'd like: the agent gets its own tab in the terminal drawer, a real pty like the ones I already open. It runs its commands there, I see them as they happen, and I can hit Ctrl+C or type myself whenever. The shell stays alive across turns, so cd, env vars, an activated venv, an ssh connection, a psql prompt or a running dev server all stick around instead of every command starting from zero. Basically one long-lived session the agent and I both use.

Where this would have saved me: the agent starts a dev server, the command never "finishes", and the turn just sits there (same thing as #28067). With a shared terminal I'd see it right away and deal with it.

Rough shape, from poking around the code:

• apps/server/src/terminal/Manager.ts already does per-thread ptys, persisted history and multiple subscribers, so most of the plumbing exists
• give the agent a few T3 tools: open, write, read (only new output since the last read, capped), and wait (for a pattern, the prompt coming back, or output going quiet)
• detect when a command is done with shell integration markers (OSC 133 style) instead of waiting for pipes to close, which would also avoid the [Bug]: Agent turns stall indefinitely when a spawned long-lived child keeps client-terminal stdout/stderr open — terminal/wait_for_exit only resolves on pipe EOF #28067 hang
• keep it behind the existing approval/permission rules
• show which input came from the agent vs me, maybe pause the agent while I'm typing

My workaround today is telling the agent to drive a tmux session with send-keys / capture-pane and attaching to it from the T3 terminal. It works but it's clunky, and I have to set it up every time.

Related: #26 (add terminal output to chat), #25518 (live view of external sessions), #28067.

[humbertogontijo]

Refined cut that matches this idea, with Open Terminal from the command row, agent-owned chrome, and tabs/sections grouped by thread / lineage:

→ #30557

Asking maintainers there for Phase A (ACP/Devin first) vs waiting for full provider PTYs as in this thread.

[iput-object]

I did hope for more then this but it's reallly a good functionality to have.