core

name	core
description	agent-tui usage — spawn, snapshot, wait, interact with PTY apps via @eN refs
allowed-tools	Bash(agent-tui:*)

agent-tui core

agent-tui drives terminal / TUI apps (vim, shell, htop, claude-code, opencode, …) from an AI agent. A per-session daemon owns the PTY and serves an outline-based snapshot with @eN element refs so agents can read screens in a few hundred tokens instead of parsing terminal bytes.

This page is the canonical entry point. Specialized skills cover specific PTY apps:

agent-tui skills list                # all available skills
agent-tui skills get core --full     # this page + references + templates

Pick a verb (start here)

You want to…	Use
Run a headless CLI, get its stdout + exit code	run -- <cmd> (feed input with --stdin)
Observe / drive an interactive TUI (vim, htop, less)	spawn → wait → snapshot → press
Edit a file in one shot and capture the result	edit <path>
Stream a long / following command's output	watch -- <cmd> (or tail --follow)
Ask an AI CLI a question	ask <provider> "<prompt>"

Rule of thumb: headless data → run; an interactive screen → the spawn/snapshot/press loop. Everything below expands on these.

Timeouts

Each sugar/wait verb carries its own deadline, set with --max <ms>. The client read timeout is derived from --max, so a long deadline no longer trips a fixed client-side cap. The defaults differ by verb — pass --max explicitly for long work:

Verb	default --max
run	60000 ms (60 s)
ask	120000 ms (120 s)
wait	25000 ms (25 s)

A timed-out wait exits non-zero with the screen state at exit and a hint to raise --max — intentional, not a bug: raise --max when what you're waiting for legitimately takes longer than the default.

Two modes

There are two distinct ways to drive a child:

Mode A — subprocess as data (agent-tui run). The child has a non-interactive mode (claude -p, gh api, gpg, jq, …). You want stdin in, stdout/exit-code out. One verb does it all.

Mode B — interactive driving (spawn + snapshot + press + wait + …). The child has no headless mode (vim, htop, lazygit) or you specifically want to observe its TUI. The capability primitives let you drive it step by step.

Mode A: just run a CLI

# headless CLI: agent feeds prompt via stdin, reads answer from stdout
agent-tui run --stdin "what is 40+2" -- claude -p
# → 42

# JSON output for an agent caller
agent-tui --json run --stdin "what is 40+2" -- claude -p
# → {"argv":["claude","-p"], "exit_code":0, "stdout":"42\n", "elapsed_ms":2064}

# without stdin
agent-tui run -- gh api /user

run bundles spawn --stdin pipe + write-stdin + close-stdin + wait --exit + tail --strip-ansi + cleanup. It shuts the per-session daemon down on exit (use --keep-daemon to keep it for follow-up calls).

Mode B: the interactive core loop

agent-tui spawn -- vim /fixtures/sample.txt     # 1. Spawn a PTY
agent-tui wait --text "sample.txt"              # 2. Wait for ready
agent-tui snapshot --mode outline               # 3. Read the screen
agent-tui press ":q!<cr>"                       # 4. Act
agent-tui die                                   # 5. Tear down

Per-app adapters emit durable refs keyed by what they identify (@vim.buffer, @shell.prompt, @tmux.pane[%2]). These survive across snapshots — same ref, same logical node. You do NOT need to re-snapshot before each ref-based interaction.

The generic adapter (when no per-app adapter matches) still emits positional @eN refs that are frame-local — that's the only place the old "re-snapshot first" rule applies. Check the node's durable field if you need to know which kind you got.

See agent-tui skills get addressing for the selector grammar and the press --to '<selector>' routing model.

Spawning a process

agent-tui spawn -- htop --no-color                  # PTY stdin (interactive default)
agent-tui spawn --stdin pipe -- claude -p           # pipe stdin (headless CLI)
agent-tui spawn --stdin closed -- env               # /dev/null stdin

--stdin pipe gives the child a pipe instead of a TTY for stdin — required by CLIs that do isatty(0) and refuse a TTY stdin (claude -p, gh api, gpg). The daemon keeps the write end so later stdin / close-stdin calls can feed it.

--stdin closed ties stdin to /dev/null. Programs that try to read see EOF immediately. Right for --print-style CLIs that take the prompt as an argument.

Spawn returns a JSON envelope with the pane id (e.g. p1). The session has one pane by default; multi-pane workflows pass --pane explicitly.

Writing to a child's stdin pipe

For panes spawned with --stdin pipe:

agent-tui stdin --text "hello world"            # write literal bytes
agent-tui stdin --bytes-hex "68690a"            # or hex
agent-tui close-stdin                           # EOF the child's stdin

For PTY-stdin panes, use type / press / send-ansi instead — those write through the master PTY (which IS stdin for PTY mode).

Reading raw output bytes

agent-tui tail                                  # all bytes the child has written
agent-tui tail --strip-ansi                     # plain UTF-8 text (no escape sequences)
agent-tui tail --since 1024                     # bytes from offset 1024 onward
agent-tui tail --follow --strip-ansi            # stream new bytes live to stdout
agent-tui --json tail --follow                  # NDJSON envelope per chunk + final {type:"eof"}

tail returns next_since so a follow-up call (tail --since <next_since>) returns only NEW bytes. For live observation of a slow child, use --follow: the daemon streams chunks as bytes arrive and terminates with a {type:"eof", exit_code:N} envelope when the child exits.

Editing a file and saving

agent-tui spawn -- vim /work/notes.md
agent-tui wait --text "notes.md"
agent-tui press "i hello<esc>"                  # enter insert, type, leave insert
agent-tui wait --text "\[\+\]"                  # vim's modified-marker
agent-tui press ":w<cr>"
agent-tui wait --text "written"
agent-tui snapshot
agent-tui press ":q<cr>"

press accepts vim-style key notation: <cr> newline, <esc>, <f5>, <c-c>, etc. Plain text inside is typed literally.

Typing literal text

agent-tui spawn -- bash -c "echo -e 'apple\nbanana\ncherry' | fzf"
agent-tui wait --text "3/3"
agent-tui type "ban"                            # types b-a-n literally
agent-tui wait --text "1/3"
agent-tui snapshot
agent-tui press "<c-c>"                         # cancel

type is for literal text (no key-notation parsing). press is for key combinations. send-ansi is for hex-encoded byte sequences when you need to emit bytes the PTY isn't parsing through readline.

Sending raw ANSI / escape sequences

agent-tui spawn -- less /work/log.txt
agent-tui wait --text "log.txt"                 # less shows the FILENAME, not a ":" prompt
agent-tui send-ansi 2f6e6565646c650d            # bytes for /needle<CR>
agent-tui wait --text "needle"
agent-tui snapshot
agent-tui press "q"

Use send-ansi for application-level byte sequences (slash-search in less, OSC sequences, mode toggles). Pass bytes as hex; for ordinary typed text plus key tokens, prefer press.

Waiting for screen state

agent-tui spawn -- bash -c "echo -e 'a\nb\nc' | fzf"
agent-tui wait --text "3/3"                     # regex over the screen
agent-tui wait --idle 150                       # 150ms of no changes
agent-tui snapshot

wait has five shapes. Pick the most specific one:

Form	Use it when
wait --ref '<selector>' [--gone]	A structured node is the ground truth (preferred — see addressing)
wait --text "regex"	No adapter outline available; matching rendered cells
wait --hash <hash>	Loop continuation — "wait until the screen differs from this hash"
wait --sequence <n>	Event-stream sync — "wait until event >= n"
wait --idle <ms>	Last-resort settling time (read references/wait-and-events.md first)

See references/wait-and-events.md for the sequence-number model and why --idle is a code smell when used alone.

Reading the screen

agent-tui snapshot                              # default = outline
agent-tui snapshot --mode outline               # compact, ref-bearing tree
agent-tui snapshot --mode text                  # visible cells as plain string
agent-tui snapshot --mode cells                 # RLE cell grid (engine-correctness)
agent-tui snapshot --mode adapter               # adapter-specific tree
agent-tui snapshot --mode hybrid                # all four (verbose)

outline is the default and the right answer for most TUI apps. Use text when the pane is just unstructured output and you want "what does the screen say" as a plain string — much easier than parsing the RLE/base64 cells.

Reach for cells when you need exact cell positions / wide chars / SGR colors (engine-correctness tests). adapter when the per-program adapter has extra structure (vim's mode + filename, shell's prompt-vs-running).

Snapshot output includes @eN refs you can use in subsequent commands (planned in P2; v0.1 returns refs as part of the outline tree). See references/snapshot-refs.md for the deep dive on ref lifetime and the four modes.

Resizing the pane

agent-tui resize 120 40                         # 120 cols × 40 rows
agent-tui snapshot

PTY-aware apps repaint on receipt of SIGWINCH. Some redraw immediately; others wait for input. Pair with wait --idle if you need the new layout before snapshotting.

Sending signals

agent-tui spawn -- htop --no-color
agent-tui wait --text "F10"
agent-tui press "q"                             # graceful quit (preferred)
# If the app is wedged:
agent-tui signal TERM                           # SIGTERM
agent-tui signal KILL                           # SIGKILL — last resort

die is the cleanup-and-exit shortcut that any test should call at the end of a scenario.

Focusing across multiple panes

agent-tui pane focus p1                         # explicit focus
agent-tui pane list                             # see what's open

Focus has three states: Auto (most-recently-spawned wins), Focused (this pane explicitly), Held (focused-pane death promotes to Held; explicit refocus required).

Recording a session

The daemon writes an asciicast-v3 trace to $XDG_STATE_HOME/agent-tui/<session>/<pane>.cast for every session. Replay with asciinema play <file>.

# The recorder is on by default. To inspect:
ls $XDG_STATE_HOME/agent-tui/default/
asciinema play $XDG_STATE_HOME/agent-tui/default/p1.cast

See references/recording.md for rotation, retention, and the v3-extension event types (markers, checkpoints).

Diagnosing install issues

agent-tui doctor                                # full diagnosis
agent-tui doctor --json                         # structured output

doctor checks: bwrap availability (sandboxed scenarios), PTY/terminfo basics, recorder write path, socket-dir permissions, agent-tui binary version vs. embedded skill version. Run before filing a bug.

Cleaning up

agent-tui die                                   # this session
agent-tui daemon shutdown                       # all sessions on this socket

The daemon also exits on PR_SET_PDEATHSIG when the CLI process tree dies, on idle timeout (default 5min), or when the monitored parent PID exits. Integration tests rely on the parent-PID monitor for zombie-free teardown.

When to load another skill

• Selectors, refs, and routing (DOM-lite addressing model — read this whenever you're using --ref, --select, or --to): agent-tui skills get addressing
• Shell sessions (bash/zsh with OSC 133): agent-tui skills get shell
• vim / nvim editing: agent-tui skills get vim
• Driving an AI CLI (opencode, pi, codex from outside): agent-tui skills get ai-cli

Full reference

agent-tui skills get core --full

Pulls in:

• references/commands.md — every subcommand, flag, alias (autogenerated from --help)
• references/snapshot-refs.md — snapshot modes + @eN lifetime
• references/wait-and-events.md — wait --text/--hash/--idle/--sequence semantics