pi-claude-style-scroll

Claude Code-style scrolling for Pi: keep the input box pinned and scroll the message list, even while typing.

pi-claude-style-scroll is a Pi extension that makes Pi's input box behave more like Claude Code's pinned composer:

• the composer/input box stays pinned at the bottom;
• status widgets and footer controls stay with the composer;
• the message history is bounded in a viewport above it;
• the mouse wheel scrolls that message viewport, including while you are typing;
• native terminal/Herdr drag-highlight copy stays usable because the default path avoids full SGR mouse capture.

This is a fork of MasuRii/pi-sticky-input. The fork keeps the sticky split-footer renderer and changes the default scrolling UX around alternate-scroll so Pi can scroll while composing.

Not affiliated with Anthropic or Claude Code. "Claude Code-style" describes the pinned input + scroll-while-typing behavior only.

Demo

Watch the MP4 demo.

Why this exists

Pi's normal terminal scrollback can fight a sticky input layout: when you wheel-scroll, the outer terminal or multiplexer may scroll old screen history instead of Pi's message list. pi-claude-style-scroll keeps the input visible and routes wheel scrolling to Pi's internal history viewport, so you can read earlier assistant output while drafting your next prompt.

Install

Git install

pi install git:github.com/EmilioAK/pi-claude-style-scroll

For a pinned install, use a tag or commit:

pi install git:github.com/EmilioAK/pi-claude-style-scroll@v0.3.1

npm

Not published yet. Once published, the intended install will be:

pi install npm:pi-claude-style-scroll

Usage

The Claude-style sticky renderer is enabled automatically when the extension loads in Pi's TUI.

The main command controls optional full mouse-wheel capture:

/claude-style-scroll status
/claude-style-scroll mouse on
/claude-style-scroll mouse off
/claude-style-scroll mouse toggle
/claude-style-scroll help

/sticky-input is kept as a compatibility alias.

Most users should leave full mouse capture off. The default alternate-scroll path is what preserves normal terminal text selection/link behavior.

Important tradeoff

Terminals encode alternate-scroll mouse-wheel events as cursor-up/cursor-down key sequences. That is what lets this extension scroll the message viewport without enabling full mouse capture.

Because those sequences are indistinguishable from physical Up/Down arrow keys at Pi's terminal-input layer, the default scrollWhileTyping: true mode means:

• mouse wheel scrolls Pi messages while you type;
• native drag-highlight/copy remains available;
• physical Up/Down arrows may scroll the message viewport instead of moving inside the prompt.

If you prefer normal Up/Down arrow editing, set scrollWhileTyping to false. Wheel scrolling will then only be treated as message scrolling when the input box is empty.

Configuration

Config is loaded from these locations in order. Later files override earlier files.

Scope	Path
Extension install root	<extension-root>/config.json
Legacy global override	~/.pi/agent/extensions/pi-sticky-input/config.json
Global user override	~/.pi/agent/extensions/pi-claude-style-scroll/config.json
Legacy project override	<project>/.pi/extensions/pi-sticky-input/config.json
Project override	<project>/.pi/extensions/pi-claude-style-scroll/config.json

A starter template is included at config/config.example.json.

mkdir -p ~/.pi/agent/extensions/pi-claude-style-scroll
cp config/config.example.json ~/.pi/agent/extensions/pi-claude-style-scroll/config.json

Default config

{
  "debug": false,
  "enabled": true,
  "splitFooterRenderer": true,
  "alternateScreen": true,
  "alternateScroll": true,
  "scrollWhileTyping": true,
  "mouseScroll": false,
  "mouseWheelScrollRows": 3,
  "keyboardScroll": true,
  "keyboardScrollRows": 10,
  "minimumHistoryRows": 3,
  "historyViewportLineLimit": 200
}

Options

Key	Type	Default	Purpose
debug	boolean	false	Enables file-only diagnostics under debug/debug.log
enabled	boolean	true	Enables the extension
splitFooterRenderer	boolean	true	Enables the sticky split-footer renderer patch
alternateScreen	boolean	true	Uses an alternate terminal screen while the session is active
alternateScroll	boolean	true	Lets compatible terminals translate wheel input into alternate-screen cursor sequences
scrollWhileTyping	boolean	true	Handles alternate-scroll cursor sequences even while the prompt contains text
mouseScroll	boolean	false	Enables full SGR mouse-wheel capture for terminals without alternate-scroll support
mouseWheelScrollRows	number	3	Rows scrolled per wheel event
keyboardScroll	boolean	true	Enables page-key and home/end history scrolling
keyboardScrollRows	number	10	Rows scrolled per keyboard page event
minimumHistoryRows	number	3	Minimum history viewport height before falling back on very small terminals
historyViewportLineLimit	number	200	Maximum retained renderer-managed history lines before choosing the visible slice

Compatibility notes

• mouseScroll: false is the preferred mode when you want terminal/Herdr drag-highlight copy.
• /claude-style-scroll on enables SGR mouse capture. Use it only if alternate-scroll does not work in your terminal and you accept that native selection/link clicks may be captured.
• Overlays and structurally unknown layouts fall back to Pi's original renderer for safety.
• The legacy PI_STICKY_INPUT_DISABLE_SPLIT_FOOTER=1 environment variable still disables the split-footer patch. The new name is PI_CLAUDE_STYLE_SCROLL_DISABLE_SPLIT_FOOTER=1.

Development

npm install
npm test
npm run typecheck
npm run build
npm run package:dry-run

Credits

Forked from MasuRii/pi-sticky-input, which provides the original sticky split-footer renderer, terminal-session management, config layering, and tests. This fork changes the default input/scroll behavior to prioritize a pinned composer that can scroll message history while you type.

License

MIT. See LICENSE. Original copyright remains with MasuRii.