pi-split-view

A pi coding agent TUI extension that owns the whole "split the main window" surface: a top band of live panels (thinking | tool usage), an optional right files dock with an edit-diff subpanel, and a response-only transcript mode — composed as one clean layout layer over pi's native transcript and editor.

╭ Thinking ──────────────────────────────────────╮ ╭ Tool Usage ───────────╮
│ …live reasoning stream…                        │ │ ✓ bash {"command":…   │
│                                                │ │ ✓ read  path/file.ts  │
╰────────────────────────────────────────────────╯ ╰───────────────────────╯
╭──────────────────────────────────────────────────────────────────────────╮
 transcript (or response-only view)                     ╭ Files (3) ──────╮│
 >                                                      │ w src/panel.ts  ││
─────────────────────────────────────────────────────── │ ✎ diff preview  ││
 model · context · status                               ╰─────────────────╯

Example

Features

• Thinking panel — live reasoning stream (coalesced flushes, bounded buffers), newest window with full history left in the transcript.
• Tool Usage panel — every tool call with status/output preview, compact or full detail, and its duration (a live elapsed counter while it runs); history is rebuilt from the session branch on resume/branch switch.
• Files panel — right dock in fullscreen (or a passive overlay in regular mode) listing read/written/seen files newest-first, with a live edit-diff subpanel (hide the subpanel with /split-diff and keep just the list); a compact status widget below the editor.
• Response-only mode — swaps the transcript for a response-only ScrollView (user + assistant text, pi's own components) with a dim dashed rule between successive assistant answers (/split-divider, config answerDivider), reusing pi's editor dock verbatim; native parity for scrollback and scroll-offset semantics.
• Measurement-safe composition — one layout layer owns the whole frame; discarded intrinsic-measure passes are O(1); panels cache on (version, width) with LRU bounding; theme changes recompose; startup composes before the first paint.
• Resize-aware geometry (the band hides itself on terminals too short for it), display-column-correct truncation everywhere (CJK/emoji safe), bounded storage caps, and honest per-command feedback.

Mouse

| Where | Action | | --- | --- | | [↗] / [↙] in a panel header | expand the panel over the whole area above the editor / restore | | [×] in a panel header | hide the panel (its command brings it back) | | band's bottom border, or the line under the band | drag to change the band height | | left edge of the Tool Usage panel | drag to change the thinking ↔ tools split | | left edge of the files dock | drag to change the dock width | | wheel over a panel (frame included) | scroll that panel |

Drag-resizes behave like the matching commands: they last for the current window, and /split-save stores them.

Commands

| Command | Effect | | --- | --- | | /split | full toggle pair: OFF = all panels off (bare pi layout), ON = the panel flags saved as startup defaults (falls back to thinking + tools if the saved layout has nothing on) | | /split-thinking | toggle the thinking panel within the band | | /split-tools | toggle the tool panel within the band | | /split-tools-view | compact ↔ full tool detail | | /split-tools-width <pct> | tools panel width as % of the band (20–60, default 35) | | /files | toggle the files panel (dock in fullscreen, overlay in regular mode) | | /split-diff | toggle the files panel's edit-diff subpanel (keep the file list only) | | /split-trim-response | full transcript ↔ response-only view | | /split-divider [rule\|space] | response-only separator between successive answers: rule = dim dashed line (default), space = blank line | | /split-height <n> | band height in rows (6–40) | | /split-save | persist the current layout as startup defaults for new windows |

Toggles are session-local by default (concurrent windows don't clobber each other); only /split-save writes the config file.

Persisting your layout

Tweaks you make with the toggle commands last for the current window only. When the layout looks right, run /split-save to store it as the startup defaults for new windows (which panels are on, band height, tools width, files dock width, tool detail mode, the diff subpanel and the answer divider). /split then toggles between bare pi and that saved layout.

The band and the dock need pi's fullscreen mode ("tuiMode": "fullscreen" in settings); the files panel falls back to an overlay in regular mode.

Install

The three files are plain TypeScript loaded by pi's extension discovery — no build step.

# install as a pi package (npm or git)
pi install npm:pi-split-view
pi install git:github.com/Hugo-W/pi-split-view
# try it once without installing
pi -e npm:pi-split-view

# or copy the sources into your pi agent extensions dir
cp split-view.ts layout-manager.ts ui-panels-config.ts ~/.pi/agent/extensions/
# (restart pi, or /reload if already running)

Or load it once without installing:

pi --tui-mode fullscreen -e /path/to/split-view.ts

Requires the pi coding agent (full screen TUI mode recommended).

Not compatible with other extensions that replace pi's fullscreen layout root (e.g. pi-stereo-view): only one of them can own the layout.

Development

npm install
npm run typecheck   # tsc --noEmit, checked against pi 1.2.0
npm test            # node:test unit tests for the pure helpers

Changelog

See CHANGELOG.md.

Files

• split-view.ts — the whole extension: panels, buffers, commands, composition
• layout-manager.ts — shared single-layer layout ownership around pi's base root
• helpers.ts — pure helpers (truncation, caps, geometry, durations, stream tail)
• ui-panels-config.ts — validated startup-default config (~/.pi/agent/ui-panels.json)

License

MIT