# Review: Interactive Terminal UI (Textual TUI)

**Reviewer**: Principal Systems Engineer (Google/Stripe caliber)
**Branch**: `colonyos/give_me_fucking_awesome_ux_that_is_a_fucking_amazing_experience_and_it_gets_peop`
**PRD**: `cOS_prds/20260323_190105_prd_give_me_fucking_awesome_ux_that_is_a_fucking_amazing_experience_and_it_gets_peop.md`

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## Checklist Assessment

### Completeness
- [x] FR-1: TUI Entry Point — `colonyos tui` command and `--tui` flag both implemented, graceful ImportError fallback
- [x] FR-2: Transcript Pane — `TranscriptView` wraps `RichLog`, all 8 callback types rendered, auto-scroll tracking present
- [x] FR-3: Composer Pane — `Composer` with auto-grow (3-8 lines), Enter submits, Shift+Enter newlines
- [x] FR-4: Status Bar — Phase name, cost, turns, elapsed time, spinner during active phases
- [x] FR-5: TextualUI Adapter — 8-method duck-type interface, janus queue bridge, sanitization on all outputs
- [x] FR-6: Keybindings — Enter, Shift+Enter, Ctrl+C (app default), Ctrl+L, Escape all bound
- [x] FR-7: Optional Dependency — `tui = ["textual>=0.40", "janus>=1.0"]` in pyproject.toml, import guarded
- [x] FR-8: Output Sanitization — All text routed through `sanitize_display_text()` in adapter

### Quality
- [x] All tests pass (1687 existing + 86 new TUI tests)
- [x] No linter errors observed
- [x] Code follows existing project conventions (duck-type UI interface, ui_factory pattern, optional dependency groups)
- [x] Dependencies are minimal and justified (textual, janus)
- [x] No unrelated changes — clean diff touching only TUI-related files + CLI entry points + pyproject.toml

### Safety
- [x] No secrets or credentials in committed code
- [x] No destructive operations
- [x] Error handling present: ImportError graceful fallback, queue consumer CancelledError handling, empty-text guards

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## Findings

- [src/colonyos/cli.py:4238-4252]: **Race condition on concurrent submits** — Each call to `_run_callback` creates a new `TextualUI(queue.sync_q)` adapter with its own `_turn_count`, `_text_buf`, and `_tool_*` state. If the user submits a second prompt while the first is still running (the worker uses `exclusive=False`), both orchestrator threads will push interleaved events onto the same janus queue. The transcript will render a garbled interleaving of two concurrent pipeline runs. Consider either (a) setting `exclusive=True` on `run_worker` to serialize submissions, or (b) adding a "busy" guard in `on_composer_submitted` that rejects input while a run is active. This is the most operationally dangerous issue — a confused user hitting Enter twice could waste significant budget on two parallel runs.

- [src/colonyos/tui/app.py:156-163]: **Lambda closure captures mutable reference** — `lambda: self._run_callback(text)` captures `text` correctly (local variable), but `self._run_callback` is a late-bound attribute set after construction (`app_instance._run_callback = _run_callback`). This works but is fragile — if anyone reassigns `_run_callback` between mount and submission, the wrong callback runs. Minor, but worth noting.

- [src/colonyos/tui/app.py:97-115]: **on_unmount cleanup is good** — Consumer task cancellation and queue close are handled properly. The `CancelledError` catch is correct.

- [src/colonyos/tui/widgets/status_bar.py:87-91]: **Spinner timer interval of 0.1s** — 10Hz timer ticking `_render_bar()` which calls `self.update()` with a full Rich `Text` rebuild. This is fine for a single widget but worth monitoring if the status bar ever gets more complex. No issue today.

- [src/colonyos/tui/adapter.py]: **Thread safety is correct** — The adapter's mutable state (`_tool_name`, `_text_buf`, etc.) is only accessed from the single orchestrator worker thread. The janus `SyncQueue.put()` is the only cross-thread operation, which is inherently thread-safe. Good design.

- [src/colonyos/tui/widgets/transcript.py:56-63]: **on_scroll_y auto-scroll tracking** — Clean implementation. The threshold of 3 lines is reasonable. One edge case: `virtual_size.height` could be 0 on first render before any content, but `max_scroll <= 0` guard handles that.

- [src/colonyos/tui/adapter.py:162-183]: **_try_extract_arg JSON parsing** — Repeatedly attempts `json.loads()` on incomplete JSON during streaming. The `except (json.JSONDecodeError, TypeError)` catch returns `None`, so partial JSON is silently retried. This is correct — the argument eventually resolves on `on_tool_done`. Performance-wise, repeated JSON parse attempts on large tool inputs (e.g., file writes) could be slightly wasteful, but the early `_tool_displayed` flag short-circuits after first success.

- [src/colonyos/tui/widgets/hint_bar.py:26]: **Ctrl+C listed in hints but not explicitly bound** — The hint bar advertises "Ctrl+C cancel" but there's no explicit Ctrl+C binding in the app. This relies on Textual's default Ctrl+C behavior (which exits the app). The PRD says "cancel current running phase", not "exit the app". This is a gap — Ctrl+C should cancel the active worker thread/phase, not kill the entire TUI. However, implementing proper phase cancellation requires threading cancellation tokens through the orchestrator, which is reasonably deferred to v2.

- [tests/tui/]: **86 tests with good coverage** — Adapter tests use a `FakeSyncQueue` to avoid needing a running event loop, which is smart. App tests use Textual's `run_test()` harness. Coverage spans all widgets, the adapter, CLI integration, and dependency checking. No obvious gaps for v1 scope.

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## Synthesis

This is a well-executed v1 that ships the minimum viable TUI without disturbing the existing system. The architecture is sound: the janus queue bridge between the synchronous orchestrator thread and Textual's async event loop is the right approach, and the adapter correctly confines all mutable streaming state to the single worker thread. The `ui_factory` injection point was already established by the Slack integration, so the TUI plugs in cleanly without modifying the orchestrator.

The most concerning operational issue is the `exclusive=False` on worker dispatch, which allows concurrent pipeline runs from rapid user submissions. At 3am, a confused developer hitting Enter twice could trigger two interleaved runs burning double budget with garbled transcript output. This should be `exclusive=True` or gated with a busy flag — it's a one-line fix.

The Ctrl+C gap (exits app vs. cancels phase) is worth noting but acceptable for v1 — proper phase cancellation requires cancellation tokens threaded through the orchestrator, which is a larger change. The hint bar should perhaps say "Ctrl+C quit" instead of "Ctrl+C cancel" to match actual behavior.

Test coverage is thorough for v1 scope. Zero regressions on the existing 1687 tests. Dependencies are minimal and justified. Code quality matches project conventions.

VERDICT: approve

FINDINGS:
- [src/colonyos/cli.py:4238-4252]: Race condition — concurrent submits interleave on shared queue. Set `exclusive=True` on `run_worker` or add busy guard. (Medium severity, budget risk)
- [src/colonyos/tui/widgets/hint_bar.py:26]: Ctrl+C hint says "cancel" but actually exits app. Should say "quit" or implement phase cancellation. (Low severity, UX confusion)
- [src/colonyos/tui/app.py:156]: Lambda captures late-bound `_run_callback` attribute — works but fragile. Consider passing callback via constructor properly. (Low severity, maintainability)

SYNTHESIS:
Solid v1 implementation that cleanly adapts the existing PhaseUI callback architecture to a Textual TUI via a well-designed janus queue bridge. Thread safety is correctly handled, the adapter confines mutable state to the worker thread, and the janus queue provides the only cross-thread boundary. 86 new tests pass alongside 1687 existing tests with zero regressions. The concurrent-submit race is the only operationally significant finding — it's a one-line fix (`exclusive=True`) that should be made before merge but doesn't block approval. Ship it.
