Four coding agent TUIs all follow the same two rules: tools maintain constant height (one-line summary, never jumping from 0 to N lines) and never auto-collapse (only user-initiated expand/collapse). looplane violates both.
OMP builds a custom TUI engine (packages/tui + packages/coding-agent/src/tui) rather than using React/Ink. Core designs: differential rendering (repaint only changed lines via reference equality), explicit history contract, composer multi-modal input & keybindings system. This article analyzes architecture decisions and implementation details from source code.
Complete pi-tui core analysis: Virtual DOM Diff for flicker-free rendering, Component lifecycle, Layout Engine (Flex-like), CSI 2026 Synchronized Output avoiding partial frame tearing, Keybindings Manager, Alt Screen, Bracketed Paste, Kitty/iTerm2 Image Protocol, built-in components (Markdown, Editor, Selector, Diff, Border, Loader, etc.).
Looplane's TUI and plain CLI are two interfaces over the same runtime paths. The CLI selects a presentation mode from TTY state and flags, runners emit events, and the TUI projects those events into thinking, tool, approval, verification, and terminal states. The screen distinguishes native and external runtimes without treating UI entry points as proof of backend maturity.
A blank config file drives people away; a bad credential discovered too late drives them away faster. All five mature agents treat setup as a first-class state, and looplane adds the step most of them skip: verify the key right after saving it.
Mature coding agent TUIs never print the event stream directly — they build a typed projection layer first and update it in place. looplane took three steps (full-screen composition, runtime-first dual modes, removing the Ask/Agent split) before two old constraints — non-streaming output and resume-without-replay — were truly lifted.
A Claude Code- or Codex-style TUI depends on long-lived sessions, typed transcripts, and approval at tool boundaries—not a screen full of color.
Cursor CLI brings the IDE agent to the terminal with an interactive TUI and headless mode, Plan/Ask/Agent modes, Cloud Handoff, and CI/CD integration. Billing now runs on two separate usage pools: Cursor's own models (Grok 4.6/4.5, Composer 2.5) and third-party models (Pro includes $20, Pro+ $70, Ultra $400).
OpenCode is an open-source AI coding agent written in TypeScript (MIT, ~198K GitHub stars, repo at anomalyco/opencode) with a built-in TUI, 75+ LLM providers, LSP integration, a Vim-style editor, SQLite session management, and a desktop app. Free, no subscription, local or cloud models.
The Control UI gained a session rail: it uses a utility model to produce a run digest and attaches a read-only companion thread, so you can ask what a session is doing without entering or interrupting the main agent run. Its contents never enter chat.history.