XLI: Open-Source Python Library for Claude Code-Style Terminal UIs

If you've tried to build your own coding agent, you've probably noticed the terminal UX is half the work. The Claude Code style transcript — where messages stream in, tool calls flip from running to done in place, and approvals pop up inline — is genuinely hard to reproduce. The team behind XLI kept rewriting this same layer every time. Full TUI frameworks like Textual (and even Rust-backed Ratatui bindings) take over the whole screen with their own widget tree, which kills your normal terminal scrollback. Lower-level toolkits leave you rebuilding streaming markdown, mutable tool cards, inline approvals, and a real input box from scratch.

So they built their own rendering engine and pulled it out into a library called XLI.

What You Get

• Streaming markdown responses
• Slash commands
• u/file mentions
• Tool cards that update in place
• Inline approvals and pickers
• ESC to interrupt
• A status bar

The key design choice: it renders inline, so your transcript flows into the terminal's normal scrollback and stays selectable, scrollable, and searchable. It does not hijack the screen.

Framework-Agnostic

XLI does not care if your agent loop is Claude, OpenAI, or your own thing. It's framework-agnostic, so you can drop it into any Python-based agent architecture.

Installation

pip install python-xli

GitHub: vitalops/xli