Imported from gabrielmoreira/agent-skills-mirror (mirrors/repos/Hmbown@Codewhale/crates/tui/AGENTS.md). Install upstream with npx skills add gabrielmoreira/agent-skills-mirror --skill tui. Copyright stays with the author.

TUI agent guidance

Scope: the terminal UI, its embedded runtime engine, and user-visible behavior. Read the repository guidance first.

UI contracts

• One owner per fact: mode, permission and live counts in the posture bar (phase_strip.rs, row 1 under the composer); model, context and the session metrics — cost, ttft, tok/s, output tokens — in the metrics line (infoline.rs, row 2); the roster and to-do in the work surface; receipts, the active row and the phase in the transcript. Key hints come from the shell_key_routing binding table, never from a string literal.
• Status-bar ink goes through palette::grammar (docs/design/STATUS_BAR_COLOR_GRAMMAR.md). Do not invent an eighth semantic or spend Failure red on non-failure chrome.
• Derive state from typed enums such as ShellPhase and OceanTreatment. Renderers must not infer state from English strings or invent lifecycle state.
• Keep settled output still. Motion is semantic, bounded, and fully disabled by reduced-motion settings.
• Route notices through the toast system, with typed level and lifetime; do not add new writes to the legacy status_message sink.
• Compact layouts remove chrome before content. Selectable rows need recorded hitboxes, visible focus, keyboard/mouse parity, and confirmation for destructive actions.
• User-visible prose uses tr(locale, MessageId::...). Commands, key names, and glyphs are composed in code. Follow locales/AGENTS.md for string changes.

Verification

Select the smallest evidence that answers the actual risk. Direct PTY or terminal behavior is stronger evidence for visible UX than an assertion over render internals. Use a focused existing test for safety, data integrity, protocol, or a reproduced regression when useful. Do not add tests by default, and do not require both full suites or workspace Clippy for an unrelated leaf change. These are available release/cross-cutting gates, not per-edit ritual:

cargo test -p codewhale-tui --lib --locked
cargo test -p codewhale-tui --tests --locked
cargo clippy --workspace --all-targets --locked -- -D warnings

--lib and --tests are disjoint; choose the target that owns the behavior. Use both or the workspace gate only when the risk genuinely spans both. scripts/dev-test.sh <area|path> [filter] prints and runs the fastest targeted invocation for a source path (for example scripts/dev-test.sh crates/tui/src/elapsed.rs). It uses cargo nextest run when nextest is installed (CODEWHALE_DEV_NEXTEST=0 forces libtest) and applies scripts/dev-cache.sh so a new worktree gets an isolated Cargo build-dir. For PTY failures, reproduce the behavior directly before changing it. Script one input at a time and capture after the UI settles. Choose the terminal sizes relevant to the change from 40x12, 60x16, 80x24, 100x32, and 140x40; judge motion from repeated frames, not a single screenshot. Remove inherited NO_COLOR, TERM=dumb, and tmux motion overrides when they would invalidate the observation.