* fix(tui): word-wrap composer input
Wrap composer input at word boundaries and anchor the good-vibes heart to the full composer row.
* test(tui): cover composer word wrap edge
Add regression coverage for moving the next word instead of splitting it at the composer edge.
The lazy startup panel could remain stuck on the placeholder when no first
prompt was submitted because agent construction only started from _sess(). Keep
session.create cheap, but schedule _start_agent_build shortly after returning
the placeholder so tools/skills hydrate automatically.
Also replace the ugly placeholder bar rows with compact unicode-animations
braille loaders for the tools and skills sections.
Tests:
- python -m py_compile tui_gateway/server.py
- cd ui-tui && npm run type-check && npm run build
- cd ui-tui && npm test -- --run src/__tests__/useSessionLifecycle.test.ts src/__tests__/useConfigSync.test.ts
- scripts/run_tests.sh tests/tui_gateway/test_protocol.py::test_sess_found tests/tools/test_code_execution_modes.py tests/tools/test_code_execution.py
Match classic CLI perceived startup behavior: show the TUI shell and composer
before constructing the full AIAgent. session.create now returns a lightweight
placeholder session with lazy=true and no longer starts _make_agent eagerly.
The first method that needs the agent triggers _start_agent_build() via _sess();
prompt.submit is routed through the RPC worker pool so that the initial wait for
agent construction does not block the stdio dispatcher.
The intro panel renders skeleton rows for tools/skills while the real
session.info payload is absent, then hydrates to the real tools/skills panel once
AIAgent initialization completes. Also skip the startup /voice status probe and
avoid the input.detect_drop RPC for ordinary plain-text prompts to keep early
startup/first-submit paths cheap.
Measurements on macOS Terminal.app:
- Previous full ready p50 after earlier PR commits: ~1537ms
- Lazy skeleton panel p50: ~794ms
- Original baseline full ready p50: ~1843ms
So the visible startup surface is now ~743ms faster than the prior PR state and
~1.05s faster than the original baseline. First prompt still pays the same agent
construction cost if it races the background/skeleton state, matching classic
CLI's deferred behavior.
Tests:
- python -m py_compile tui_gateway/server.py
- cd ui-tui && npm run type-check && npm run build
- scripts/run_tests.sh tests/tui_gateway/test_protocol.py::test_sess_found tests/tools/test_code_execution_modes.py tests/tools/test_code_execution.py
- cd ui-tui && npm test -- --run src/__tests__/useSessionLifecycle.test.ts src/__tests__/useConfigSync.test.ts
Address two Copilot review comments on PR #17175.
- `wrapForFrac` doc said "additive operators or whitespace" but the
implementation also matches `*` and `/`. The wider behaviour is the
one we want (nested products and fractions need parens to disambiguate
inline `/`), so the doc is updated to match instead of tightening the
regex.
- `fenceOpenAt` was flagged as "overly conservative" vs. `markdown.tsx`,
which falls back to paragraph rendering for unclosed `$$` openers.
Mirroring that fallback in the streaming chunker would prematurely
commit a paragraph rendering of the unclosed opener to the monotonic
stable prefix, where it would be frozen and become wrong the moment
the closer streams in. The asymmetry is deliberate; document why so
it isn't "fixed" again later.
Made-with: Cursor
This PR groups the TUI fixes that restore macOS Terminal usability and clean up the theme/composer regressions:
- copy transcript selections on macOS drag-release so Terminal.app users can copy while mouse tracking is enabled
- copy composer selections on macOS drag-release; composer selection is internal to TextInput and does not use the global Ink selection bus
- keep IDE Cmd+C forwarding setup macOS-only, and make keybinding conflict checks respect simple when-clause overlap/negation
- force truecolor before chalk initializes (unless NO_COLOR / FORCE_COLOR / HERMES_TUI_TRUECOLOR opt-outs apply) so the default banner keeps its gold/amber/bronze gradient in Terminal.app
- move TUI surfaces onto semantic theme tokens and preserve skin prompt symbols as bare tokens with renderer-owned spacing
- render focused placeholders as dim hint text in TTY mode instead of inverse/selected-looking synthetic cursor text
* feat(tui): pluggable busy-indicator styles (kaomoji/emoji/unicode/ascii)
The status-bar `FaceTicker` rotated through wide-and-variable kaomoji
glyphs (`(｡•́︿•̀｡)`, `( ͡° ͜ʖ ͡°)`, …) every 2.5s. Real display widths range
from ~5 to ~16 columns, so the rest of the bar (cwd, ctx %, voice,
bg counter) shifted on every cycle. Padding the verb alone (#17116)
helped but didn't address the dominant jitter source — the glyph
itself.
Add four indicator styles, configurable + hot-swappable:
* `kaomoji` (default — preserves the existing vibe; verb is now
pad-stable so the only width churn left is the kaomoji itself).
* `emoji` — single 2-col emoji frame (`⚕ 🌀🤔✨🍵🔮`).
* `unicode` — `unicode-animations` braille spinner (1-col, smooth).
* `ascii` — `| / - \` (1-col, max compat).
Wires:
* `display.tui_status_indicator` in `DEFAULT_CONFIG` (default
`kaomoji`).
* New JSON-RPC `config.set/get indicator` keys, narrow allow-list.
* `applyDisplay` reads the field and patches `UiState.indicatorStyle`,
so the existing `mtime` poll picks up `~/.hermes/config.yaml` edits
within ~5s without a TUI restart.
* `/indicator [style]` slash command (alias `/indicator-style`,
subcommand completion `kaomoji|emoji|unicode|ascii`). Bare form
shows the current style; setter fires `config.set` and
optimistically `patchUiState({ indicatorStyle })` so the live TUI
swaps immediately, matching the `/skin` UX.
* `CommandDef("indicator", ..., subcommands=...)` so classic CLI
autocomplete + TUI `complete.slash` both surface it.
* `FaceTicker` decouples spinner cadence from verb cadence — the
glyph runs at the spinner's authored interval (or `FACE_TICK_MS`
for kaomoji), the verb stays on the original 2.5s cycle, and both
re-arm cleanly when style changes.
Tests:
* `normalizeIndicatorStyle` rejects unknown / non-string input.
* `applyDisplay → tui_status_indicator` covers fan-out + fallback.
* `/indicator <style>` hot-swaps `UiState.indicatorStyle` after a
successful `config.set`.
* `/indicator sparkle` rejects with the usage hint and never hits
the gateway.
* Slash-parity matrix gets `'/indicator'` → `config.get`.
Validation:
cd ui-tui && npm run type-check — clean; npm test --run — 398/398.
scripts/run_tests.sh tests/test_tui_gateway_server.py
tests/hermes_cli/test_commands.py — 220/220.
* chore(tui): drop /indicator-style alias to declutter autocomplete
* fix(tui): drop verb-width pad — /indicator handles glyph jitter directly
* fix(tui): unicode indicator style hides the verb (cleanest option)
* refactor(tui): single source of truth for INDICATOR_STYLES; cleaner error format
Round 1 Copilot review on PR #17150:
- Exported `INDICATOR_STYLES` const tuple from `interfaces.ts`;
`IndicatorStyle` union type is derived from it. `useConfigSync`
builds its validation Set from the tuple, and `session.ts` uses it
for both the usage hint and the runtime allow-list — adding/removing
a style now touches one line.
- Backend `config.set indicator` error message: switched
`sorted(allowed)` list repr to `pick one of ascii|emoji|kaomoji|unicode`
(matches the TUI usage hint), and reports the normalized `raw`
instead of the original `value`. Backend allowed tuple now has a
comment pointing back at `INDICATOR_STYLES` so the two stay aligned.
Note: kept the verb portion unpadded per design intent — fixed-width
padding was the exact UX the `/indicator` command was added to remove.
Stable width comes from the glyph; verbs cycling is part of the kawaii
aesthetic. Reply on the verb thread will explain.
* fix(tui): drop type collapse + gate verb timer + DEFAULT_INDICATOR_STYLE
Round 2 Copilot review on PR #17150:
- `tui_status_indicator?: 'ascii' | ... | string` collapses to `string`
in TS — consumers got no narrowing. Documented as plain `string` with
a comment about runtime validation via `normalizeIndicatorStyle`.
- `FaceTicker` always started a 2.5s verb interval, even for the
`unicode` style which hides the verb entirely. Now gated on
`showVerb` from `renderIndicator` — `unicode` stays calm.
Pre-emptive self-review (avoid round 3):
- Three call sites duplicated the literal `'kaomoji'` default
(uiStore, normalizeIndicatorStyle, slash command). Added
`DEFAULT_INDICATOR_STYLE` to interfaces.ts and threaded it through
so changing the default touches one line.
* fix(tui-gateway): normalize config.get indicator output to match TUI render
Round 4 Copilot review on PR #17150: `config.get` for `indicator`
returned the raw `display.tui_status_indicator` value without
validation, so a hand-edited config.yaml with stray casing or an
unknown style would leave `/indicator` printing one thing while
the TUI rendered the kaomoji default (frontend's
`normalizeIndicatorStyle` does this normalization on receive).
Lifted the allow-list to module scope as `_INDICATOR_STYLES` /
`_INDICATOR_DEFAULT`, reused by both `config.set` and `config.get`.
Comment notes the alignment with `INDICATOR_STYLES` /
`DEFAULT_INDICATOR_STYLE` in interfaces.ts so adding/removing a
style is a one-line change on each end.
Tests cover: known value verbatim, casing/whitespace normalize,
unknown→default, unset→default.
* fix(tui-gateway): preserve falsy-input diagnostics in config.set indicator error
Round 5 Copilot review on PR #17150: `raw = str(value or "").strip().lower()`
collapsed any falsy non-string (`0`, `False`, `[]`) to empty string,
so the error message read `unknown indicator: ` with nothing after —
losing the original input.
Switched to `("" if value is None else str(value)).strip().lower()`
so only `None` (the genuine 'no value' case) becomes blank. Used
`{raw!r}` in the error so the diagnostic is unambiguous (`'0'` vs `0`).
Tests:
- known-value happy path (`'EMOJI'` → `'emoji'`)
- falsy non-string inputs (`0` / `False` / `[]`) surface meaningfully
- `None` keeps the blank-repr error
Tables rendered through `<Md>` had no separator and no header weight,
so they read as a paragraph with extra whitespace. This adds two tiny,
border-free changes that survive Ink's grapheme-approximate column
widths better than a full outline:
* Bold the header row, keeping the existing amber colour.
* Insert a dim `─`-dashed rule between the header and body rows.
We deliberately stay away from a full outline — column widths are
measured via `stripInlineMarkup(...).length`, which is grapheme-aware
but still off by a cell on East Asian wide characters and emoji-mid-
cell strings. A header rule plus the existing 2-space column gap
gives the visual hierarchy the issue asks for without amplifying that
inaccuracy into a misaligned border.
Validation: `npm run type-check` clean, `npm test --run` 389/389.
- moveCursor(extend=true) now collapses to the bare cursor when the
computed offset equals the existing anchor instead of leaving a
zero-length sel. Without this, Shift+Left at col 0 / Shift+Home at
start would silently hide the hardware cursor (selected truthy)
without rendering any highlight.
- _tui_need_npm_install also catches UnicodeDecodeError so a corrupted
/ non-UTF8 lockfile falls back to the mtime path the docstring
promises instead of crashing.
Made-with: Cursor
* feat(tui): auto copy-on-select for transcript text
Drag in the transcript already highlighted but you had to press Cmd+C to
land it on the clipboard, and the highlight cleared on copy — most users
never realised selection existed. Now drag-release fires copySelectionNoClear
so the text is on the clipboard immediately while the highlight stays put,
matching iTerm2's "Copy to pasteboard on selection" default. Esc clears.
Behaviour:
- Single click in the input still positions the cursor (TextInput onClick).
- Single click in the transcript still does nothing destructive.
- Double / triple click select word / line, then drag extends.
- /copyselect [on|off|toggle] (alias /cos) flips the setting at runtime,
HERMES_TUI_DISABLE_COPY_ON_SELECT=1 disables at startup, persists via
display.tui_copy_on_select in config.yaml.
Help overlay now lists drag-select, multi-click, and click-to-position
so the gestures are discoverable.
Made-with: Cursor
* fix(tui): support prompt text selection gestures
Add mouse drag selection and Shift+Arrow/Home/End extension inside the TUI composer so prompt text behaves like a normal editable field while keeping click-to-position and right-click paste intact.
Made-with: Cursor
* Revert "feat(tui): auto copy-on-select for transcript text"
This reverts commit 6701288fe0.
* fix(tui): allow composer selection from prompt whitespace
Give the composer a one-cell mouse capture pad before the editable text. The prompt glyph/gutter still does not become selectable, but dragging from the edge now anchors at input offset 0 so users do not need to hit the first character precisely.
Made-with: Cursor
* fix(tui): clear selections from blank composer space
Clicking blank space in the transcript or composer now clears active TUI/input selections like a normal text surface. TextInput clicks stop bubbling so cursor placement and selection gestures keep their local behavior.
Made-with: Cursor
* fix(tui): delegate prompt gutter drags to composer text
The prompt gutter is now an input gesture region, not selectable content. Dragging from the whitespace or prompt area anchors the composer selection at offset 0, while selection highlight/copy remains limited to actual input text.
Made-with: Cursor
* fix(tui): move composer cursor to end on selection clear
External clear actions now collapse the composer selection to the end of the input, matching normal text-field behavior after dismissing a selection.
Made-with: Cursor
* fix(tui): capture composer padding before prompt
Add an explicit mouse capture cell over the left padding before the prompt glyph. Drags starting there now delegate to the composer input at offset 0 instead of starting terminal-level selection over the prompt chrome.
Made-with: Cursor
* fix(tui): avoid npm install on lockfile mtime churn
Compare package-lock.json against npm's hidden node_modules lock by content instead of mtimes. Git checkouts and npm lock rewrites can make the root lockfile newer even when installed dependencies already match, causing hermes --tui to print Installing TUI dependencies on every launch.
Made-with: Cursor
* fix(tui): include prompt leading cell in gesture region
Use the prompt box's real layout region to cover the leading whitespace cell before the glyph. The cell now participates in mouse hit testing and delegates to composer selection instead of starting terminal-level selection.
Made-with: Cursor
* fix(tui): widen prompt-side gesture capture band
Capture a wider left-side band around the composer prompt row so drags starting in terminal gutter/padding cells are consumed and delegated to input selection, instead of triggering terminal-level selection chrome.
Made-with: Cursor
* fix(tui): make pre-prompt spacer non-selectable content
Replace the sticky-prompt fallback `Text(' ')` with an empty spacer box so the visual gap remains but no literal space character is rendered/copyable before the composer prompt.
Made-with: Cursor
* fix(tui): capture pre-prompt spacer without shifting prompt layout
Revert the widened negative-margin prompt capture band and instead capture drags on the dedicated spacer row above the prompt. This keeps prompt/text alignment stable while still delegating whitespace-start drags to composer selection.
Made-with: Cursor
* fix(tui): align prompt with status bar and capture full input row
Drop the leading prompt column from 3 to 2 so the input first character lines up with the status bar text. Wrap the prompt+input row in a single mouse-capture box and stop event propagation from TextInput's own handlers so any drag in that row delegates to composer selection without leaking to terminal-level selection.
Made-with: Cursor
* fix(tui): anchor hardware cursor during composer selection
When a composer selection covers a row exactly the column width, the rendered text fills the row and the terminal auto-wraps the hardware cursor to col 0 of the next row, leaving a ghost block beneath the prompt. Park the cursor at the start of the input box during selection so it can't escape the input region.
Made-with: Cursor
* fix(tui): hide hardware cursor during composer selection
Stop fighting auto-wrap by hiding the hardware cursor outright while the
composer has an active selection. This prevents both the ghost block under
the prompt (cursor wrapping past the last cell) and the parked-cursor block
on the first selected character. The cursor restores as soon as the
selection clears or focus changes.
Made-with: Cursor
* chore(tui): /clean — drop dead capture-pad path, dedupe gutter handlers
- TextInput: remove unused leftCaptureColumns prop and capture-pad math, drop
unused mouseApi.startAt, fold mouse offset into a single offsetAt helper,
share a MouseEventLite type across the four handlers.
- appLayout: hoist a GutterMouseEvent type and an endInputDrag callback so the
spacer/prompt/input rows share one shape.
- _tui_need_npm_install: lift the runtime-only key set to a module constant,
collapse nested isinstance checks, and document the mtime fallback.
Made-with: Cursor
* fix(tui): address copilot review on PR #16732
- Split InputSelection.clear() into clear() (cursor-preserving) and
collapseToEnd() (clear + jump to end). Cmd+C copy paths keep using
clear() so the cursor stays put; the blank-area click in useMainApp
switches to collapseToEnd() to match the requested UX.
- Spacer-row drags now force row=0 when forwarding into the input,
since the spacer's vertical origin doesn't align with the input box
and Ink mouse-capture keeps dispatching motion to the original
target. Prompt+input row drag keeps localRow because origins match.
Made-with: Cursor
* fix(tui): give TextInput Box an explicit width
After the /clean pass dropped the unused capture-pad math, the wrapping
Box also lost its explicit width and started sizing to its rendered
content. Clicks past the last character missed TextInput and fell
through to the parent prompt-row Box, which collapsed the cursor to
offset 0. Pin the Box back to `columns` so the input owns its full
column span regardless of value length.
Made-with: Cursor
* feat(tui): double-click select-all + hide cursor on terminal blur
- Track click time/offset in TextInput so a quick second click on the
same offset triggers select-all. Ink's screen-level multi-click is
bypassed once our onMouseDown captures, so the gesture has to be
detected locally.
- Extend the cursor-hide effect to also fire when the terminal loses
focus, so the hollow-rect ghost most terminals draw at the parked
cursor position disappears too.
Made-with: Cursor
* chore(tui): /clean — extract isMultiClickAt helper
Pull the click-recurrence math out of TextInput's onMouseDown into a
small isMultiClickAt(offset) helper so the handler reads as the gesture
list it actually is (multi-click → select-all, otherwise start).
Drop the redundant length>0 guard now that selectAll() already noops on
an empty value.
Made-with: Cursor
* docs(tui): explain _tui_need_npm_install content-vs-mtime comparison
Expand the docstring so future readers understand why we parse the
lockfiles instead of comparing mtimes, what the optional/peer skip
covers, how stale hidden-lock entries are handled, and when we fall
back to mtime.
- Rename `removeAt` → `removeAtInPlace` and document the mutation
contract; the old name read like a non-mutating helper.
- Hotkey table + queue header: use `Ctrl+X` / `Esc` to match the
rest of the UI (was `⌃X` / `esc`).
- Render the queued header as a single template literal so JSX
text-node whitespace can't sneak into the rendered line.
- Make `Esc` while editing beat the `terminal.hasSelection` clear:
the header promises 'Esc cancel', so an active selection
shouldn't silently consume the keystroke.
The text input's ctrl-passthrough whitelist only listed Ctrl+C and
Ctrl+B. Ctrl+X fell through to the printable-char branch and got
inserted as 'x' alongside the queue-delete action firing in
useInputHandlers.
Add Ctrl+X to the same whitelist so it bypasses the readline-style
fallback and reaches the app-level handler unchanged. When not in
queue-edit mode it's a no-op, which is fine — typing 'x' on Ctrl+X
was the wrong default anyway.
Today there's no way to remove a queued message — ↑ loads it for edit,
ctrl-K dispatches the head, but a draft you no longer want stays put
forever. ctrl-C just clears the composer and exits edit mode without
touching the queue.
Two new bindings, both gated on queueEditIdx !== null so they're
inert when the user isn't pointing at a queue item:
- ctrl-X — delete the queue item being edited, clear composer, exit
edit mode. "cut" matches the mental model and doesn't collide with
any existing binding.
- esc — cancel the edit (composer clears, item stays in queue).
Mirrors ctrl-C's existing behavior so muscle memory has two paths.
Header line now reads `queued (3) · editing 2 · ⌃X delete · esc cancel`
when in edit mode, so the affordance is discoverable without /help.
The /help hotkey table also gets a Ctrl+X entry.
ctrl-C is intentionally unchanged: it should never destroy queued
content. Cancel is non-destructive (esc / ctrl-C); only ctrl-X
removes the item.
- drop unused TUI helpers, test-only layout scaffolding, and stale public debug exports
- remove an unused profiler import and trim test-only coverage for deleted helpers
Four independent session-UX bugs reported by an external user (#16294).
/save wrote hermes_conversation_<ts>.json to CWD — invisible to
'hermes sessions browse' and easy to lose. Snapshots now write under
~/.hermes/sessions/saved/ and the command prints the absolute path plus
a 'hermes --resume <id>' hint for the live DB-indexed session.
'hermes sessions browse' default --limit raised from 50 to 500. With the
old ceiling, users with moderately long histories saw only the most
recent 50 rows and assumed older sessions had been lost.
TUI session.list (`/resume` picker) switched from a hardcoded allow-list
of 13 gateway source names to a deny-list of just { 'tool' }. Sessions
tagged acp / webhook / user-defined HERMES_SESSION_SOURCE values and
any newly-added platform now surface. Default limit 20 → 200.
ollama-cloud provider setup passes force_refresh=True to
fetch_ollama_cloud_models() so a user entering their API key sees the
fresh catalog (e.g. deepseek v4 flash, kimi k2.6) immediately instead
of waiting up to an hour for the disk cache TTL to expire.
Closes#16294.
TodoPanel now renders as a child of the most recent user message's
virtualized row container, so it visually belongs to that prompt and
follows it during scroll. Falls back gracefully when no user message
exists yet (panel just doesn't render).
CPU profile (Apr 2026, real-user scroll on 11k-line session) showed three
hot loops in the per-frame render path:
Output.get() per-frame walk: 24% total
└─ sliceAnsi(line, from, to) per write: 18% total
stringWidth(line) chain (cached + JS): 14% total
All three were re-doing identical work every frame: same string → same
clipped slice → same width.
Fixes:
1. Memoize stringWidth (8k-entry LRU) for non-ASCII strings; ASCII fast-path
skips the cache (inline scan beats Map.get for short ASCII, the >90%
case). String.charCodeAt scan up to 64 chars is cheaper than the regex
fallback.
2. Memoize wrapText (4k-entry LRU keyed by maxWidth|wrapType|text) — wrapAnsi
is pure and the same content reflows identically every frame.
3. Memoize sliceAnsi (4k-entry LRU keyed by start|end|str) for the
end-defined hot path used by Output.get().
4. Skip the slice entirely in Output.get() when the line already fits the
clip box (startsBefore=false && endsAfter=false). Most transcript lines
never exceed their container width, and tokenizing them just to slice
(line, 0, width) was pure overhead. This single fast-path drops
sliceAnsi from 18% → ~0% in the profile.
Also tighten virtualization constants (MAX_MOUNTED 260→120, OVERSCAN 40→20,
SLIDE_STEP 25→12) and cap historical-message render at 800 chars / 16
lines via HISTORY_RENDER_MAX_*; messages inside the FULL_RENDER_TAIL_ITEMS
window still render in full so reading-zone behavior is unchanged.
Validation, real-user CPU profile, page-up scroll on 11k-line session:
Output.get() self-time: 24% → 0.3%
sliceAnsi total: 18% → not in top 25
stringWidth family: 14% → ~3%
idle: 60.7% → 77.3%
Frame timings (synthetic page-up profile harness):
dur p95: ~10ms → 4.87ms
dur p99: 25ms+ → 12.80ms
yoga p99: ~20ms → 1.87ms
The remaining CPU in the profile is Yoga layoutNode + React commit,
which is the irreducible work for this UI tree size.
Adds a corner-overlay FPS readout gated on HERMES_TUI_FPS, fed by
ink's onFrame callback (so it's the REAL render rate, not a timer).
Displays fps, last-frame duration, and total frame count, colored by
threshold (green ≥50, yellow ≥30, red below).
Implementation:
* lib/fpsStore.ts — nanostore atom updated from a trackFrame()
sink. Ring buffer of last 30 frame timestamps; fps = 29/elapsed.
trackFrame is undefined when SHOW_FPS is off so ink's onFrame
short-circuits at the optional chain.
* components/fpsOverlay.tsx — tiny <Text> subscriber; returns null
when SHOW_FPS is off (React skips the subtree entirely).
* entry.tsx — composes onFrame from logFrameEvent (dev-perf) and
trackFrame (fps) so both flags can coexist. When both are off,
onFrame is undefined and ink never attaches the handler.
* appLayout.tsx — mounts the overlay as a flex-shrink=0 right-
aligned Box below the composer, conditional on SHOW_FPS.
Usage:
HERMES_TUI_FPS=1 hermes --tui
# bottom right: " 62.3fps · 0.8ms · #1234" (green/yellow/red)
Intended as a user-facing diagnostic during the scroll-perf tuning
pass — watch the counter drop while holding PageUp to see where
frames go silent, without having to run scripts/profile-tui.py in a
side terminal.
126 files post-compile with React Compiler; 352 tests still pass.
Adds a gate so we can A/B test whether bypassing the alt-screen +
viewport constraint lets the terminal's native scrollback beat our
virtualization on scroll perf.
Result: definitively NO. Inline mode is 40x worse on every metric
that moves, because AlternateScreen is what constrains the ScrollBox
to the viewport height. Without it, the ScrollBox grows to contain
every child of the transcript and every frame re-renders all 1100
messages.
Profile under hold-wheel_up (1106-msg session, 30Hz for 6s):
metric fullscreen inline delta
patches_total 28,864 1,111,574 +3751%
writeBytes_total 42 KB 1.6 MB +3881%
fps_throughput 15.8 fps 1.75 fps -89%
frames 179 18 -90%
gap_p50_ms 17 (~60fps) 726 (~1fps) +4170%
yoga_p99 34 ms 405 ms +1083%
renderer_p99 14 ms 169 ms +1062%
flickers 0 5 offscreen —
This is actually the cleanest data we've gotten so far:
* AlternateScreen is LOAD-BEARING for perf — its viewport height
constraint is what lets useVirtualHistory's culling work. No
constraint → ScrollBox grows unbounded → every fiber mounts.
* The outer terminal (Cursor's xterm.js) parsed 1.6 MB of ANSI in
under 10 seconds with drain p99 = 8.83 ms and 0 backpressure
frames. Our terminal-write hypothesis from last session was
wrong: the bottleneck is React + Yoga, not the wire.
* Doing proper inline mode (non-virtualized transcript in
scrollback, composer pinned below) is not a flag flip — it's a
different UI architecture. Leaving this flag in so anyone
re-running the experiment gets the same numbers, but not
building the architecture until we're sure the perf win is
worth the UX loss (it probably isn't — the fullscreen + virt
path is the one we should optimize, not replace).
Keeping the flag as an experiment gate. Flip HERMES_TUI_INLINE=1
and run scripts/profile-tui.py --compare to reproduce.
Profiled with scripts/profile-tui.py under hold-PageUp + hold-wheel.
The placeholder → microtask-upgrade pattern did not reduce renderer
p99 (63ms → 63ms) or max (96ms → 142ms, slightly worse). Each fresh
row still pays the Md cost — just on a follow-up commit instead of
inline — and the follow-up commit shows up as a second heavy frame
a few ms later.
The real bottlenecks turned out to be:
1. wheel step too large (fixed in 7ca16eea)
2. outer terminal ANSI parse throughput (diagnosing next)
3. React commit frequency during hold-scroll (needs coalescing)
None of which DeferredMd addresses. Clearing the complexity so the
next experiments land on a simpler substrate.
Adds DeferredMd — a wrapper around <Md> that renders a lightweight
<Text> placeholder on first mount and upgrades to the full markdown
subtree on a queueMicrotask follow-up. Rationale: fresh MessageLine
mounts during PageUp hold run our markdown tokenizer + syntax
highlighter synchronously, producing the 63-112ms renderer spikes
profiled earlier. A plain <Text> placeholder only needs Yoga to wrap
the pre-stripped string (no tokenizer, no highlight), then the Md
subtree builds in a follow-up React commit.
Upgrade cache: once a (theme, compact, text) tuple has been upgraded,
a WeakMap-keyed Set remembers it so remounts (scroll-out then
scroll-back) mount straight into <Md> — no placeholder round-trip.
WeakMap on theme means palette swaps re-upgrade naturally.
Honesty note: profiling under hold-PageUp showed this didn't reduce
renderer p99 measurably — the upgrade commit just pays the Md cost on
a follow-up frame instead of inline. The bigger bottleneck turned out
to be React commit frequency (3.5 commits/sec during 30Hz scroll
input, with 200ms+ silent gaps between commits dominating perceived
FPS), which this change doesn't address. Keeping the deferred path
anyway because:
1. It's correct and tested — no regressions across 352 tests
2. Defensive for pathological fresh-mount cases (giant code blocks,
wide tables) that aren't in the current profile fixture
3. Pairs naturally with useVirtualHistory's useDeferredValue to keep
React's concurrent scheduler able to interrupt upgrade commits
If the follow-up perf investigation (terminal write throughput / patch
volume / commit frequency) shows DeferredMd is net-neutral-or-worse in
practice, this can be reverted with a one-line swap back to <Md> in
messageLine.tsx:115.
Companion to the streaming 2-column fix in 7242361a — these two
touched messageLine.tsx together so they land as a pair.
StreamingMd returned <><Md/><Md/></> — a bare Fragment with two <Md>
children. Each <Md> returns a <Box flexDirection="column">, but its
parent in messageLine.tsx (line 169) is `<Box width={...}>` with no
flexDirection, which Ink defaults to 'row'. So during streaming the
two column boxes rendered side-by-side, producing the visible "tokens
jumble into two columns until it fixes itself" bug — the "fix" was
message.complete flipping isStreaming→false, which swaps the
StreamingMd subtree for a single DeferredMd/Md child (no siblings → row
direction is harmless).
Wrap the two <Md> siblings in a flexDirection="column" Box so they
stack. Localized fix so the non-streaming path (single-child, works
fine in a row parent) is untouched.
Reported by user:
> "tokens streaming... going into 2 columns randomly and jumbling
> together until it fixes itself"
No test changes — findStableBoundary tests still pass (the layout
change is parent-structural, not in the boundary logic). Build clean,
tsc clean, 352 tests pass.
Split in-flight assistant text at the last stable block boundary so only
the unclosed tail re-tokenizes per stream delta. Previously the full
text was rendered as plain <Text> during streaming and only flipped to
<Md> at message.complete — cheap per delta but loses live markdown
formatting.
New StreamingMd component holds a monotonically-growing stablePrefix
in a ref (idempotent under StrictMode double-render), renders it as
one <Md> that memoizes across deltas, and renders the unstable suffix
as a second <Md> that re-parses on each delta. Cost per delta drops
from O(total length) to O(unstable length).
findStableBoundary walks back to the last "\n\n" outside an open
fenced code block — splitting inside an open fence would orphan the
opener and break highlighting in the prefix.
Adapted from claude-code's src/components/Markdown.tsx:186 but built
on our line-based tokenizer instead of marked.lexer. 9 new tests cover
fence balance, boundary walk, and empty input.
Part of the --tui perf audit (see audit #7).
