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Command history

Loom's Commands panel lists every shell command you've run inside a Loom terminal pane: the command itself, its working directory, when it ran, how long it took, and whether it succeeded.

It's available as a panel kind in any Prompt workspace. Add it the same way you'd add a Terminal or Editor block.

How it works

Loom installs a small zsh shim at ~/Library/Application Support/Loom/shell/.zshrc in the Loom build. When a Loom terminal pane spawns its login shell, the env it passes through includes:

  • ZDOTDIR=~/Library/Application Support/Loom/shell — points zsh at the shim directory.
  • LOOM_SESSION_ID=<uuid> — identifies which Loom terminal session ran the command.

The shim's first job is to source your real config (~/.zshenv, ~/.zprofile, ~/.zshrc, ~/.zlogin) so nothing about your existing setup changes. After that, it registers preexec and precmd hooks that write a single JSON line per command to ~/Library/Application Support/Loom/shell/history.jsonl:

{"started":1778302670,"ended":1778302675,"exit":0,"cwd":"/Users/me/code/foo","command":"git pull","session":"7E3..."}

The Commands panel polls this file every 2 seconds via CommandHistoryService, parses the most recent records (capped at 500), and renders the list newest-first.

Workspace filtering

Each row carries the cwd it was run from. The panel header has a Workspace only checkbox: when on (default), the panel hides commands whose cwd isn't inside the workspace's folder. When off, you see every command across every Loom terminal you've ever opened.

Per-row actions

  • Copy copies the command text to the macOS pasteboard.
  • Send (when at least one Terminal block exists in the active workspace) submits the command to the first terminal session as if you'd typed it. Useful for re-running something from an earlier session without retyping.

Output capture (v2.2.0+)

Commands submitted through Loom's UI (Commands panel Send, inline card Rerun, ⌘K palette rerun) are wrapped in the shim's __loom_capture helper, which tees their stdout+stderr into a per-command file under ~/Library/Application Support/Loom/shell/output/. The matching JSONL record carries an extra output field with the full path.

Hand-typed commands skip this wrapping entirely so interactive TUIs (vim, top, ssh, tmux) keep working unchanged. If you want capture for a hand-typed command, prefix it with __loom_capture '...' yourself.

Cards in both the Commands panel and the inline-card terminal view show a chevron when their record has captured output. Click to expand an inline reader (capped at 1 MB, with a truncation notice if exceeded; selectable text for copy-paste).

Exit codes are preserved across the tee pipeline via zsh's pipefail and ${pipestatus[1]}.

What's not captured (yet)

  • Output for hand-typed commands stays uncaptured by design (TUIs would break). Prefix manually with __loom_capture '...' if you want it.
  • Non-zsh shells are not supported. The shim is zsh-specific. If your $SHELL is bash or fish, the shell still runs normally; nothing breaks, but no commands appear in the panel.
  • Commands run before Loom started writing the shim (i.e. older zsh sessions or terminals from outside Loom) are not in the log.

Command history vs. terminal transcripts

Command history is structured metadata: command text, cwd, timing, exit code, session id, and optional output capture for commands sent through Loom UI. Terminal transcripts are separate full PTY logs saved under Terminal History/ so closed terminal sessions can be reviewed or recovered later.

Privacy

The history file lives entirely on disk inside Application Support. Nothing leaves your Mac. Loom reads the file with standard FileManager calls and does not watch via FSEvents (which would require a separate sandbox entitlement).

Removing the integration

Use Settings -> Shell and turn off Capture commands from Loom terminals. The change applies to new terminal panes. To remove the existing files, delete ~/Library/Application Support/Loom/shell/.zshrc and ~/Library/Application Support/Loom/shell/history.jsonl. Loom recreates the shim on launch, but it is not sourced when the setting is off.