- 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
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.
Replaces the static WHEEL_SCROLL_STEP=1 multiplier on wheel events
with an adaptive accel state machine that infers user intent from
inter-event timing.
Algorithm ported straight from claude-code's
src/components/ScrollKeybindingHandler.tsx. All tuning constants,
the native/xterm.js path split, the encoder-bounce detection, the
trackpad-burst signature → all theirs. This file is a mechanical
port into our module structure.
What it does:
precision click (>500ms gap) 1 row/event (deliberate scan)
sustained mouse (40-200ms) 2-6 rows (decay curve)
detected wheel bounce ramps to 15 (sticky wheel-mode)
trackpad flick (5+ <5ms) 1 row/event (burst detect)
direction reversal reset to base
Two implementation paths:
* native terminals (ghostty, iTerm2, Kitty, WezTerm) — linear
window-ramp + optional wheel-mode curve triggered by detected
encoder bounce. SGR proportional reporting handled via the
burst-count guard.
* xterm.js (VS Code / Cursor / browser terminals) — pure
exponential-decay curve with fractional carry. Events arrive
1-per-notch with no pre-amplification, so the curve is more
aggressive.
Selected at construction via isXtermJs() from @hermes/ink (now
exported). Per-user tune via HERMES_TUI_SCROLL_SPEED (alias
CLAUDE_CODE_SCROLL_SPEED for portability).
13 unit tests covering direction flip/bounce/reversal, idle
disengage, trackpad-burst disengage, frac invariants, and the
native vs xterm.js branches.
Profiled under --rate 30 (stress test) and --rate 10 (realistic
sustained scroll): accel ramps to cap=6 at 30Hz burst, decays to
1-3 rows at sparse 10Hz clicks. Perf is comparable to baseline
because accel IS multiplying step — the win is perceptual (fast
flicks cover distance, slow clicks keep precision), not raw fps.
Companion to the earlier WHEEL_SCROLL_STEP=1 change: that set the
base; this modulates around it.
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).
Follow-up on #16020 salvage. Three corrections:
1. Truth signal for /copy
Before: success was 'OSC 52 sequence was emitted to stdout'. That's
false on local Linux inside tmux (emitSequence=false), so /copy kept
printing 'clipboard copy failed' to users whose xclip/wl-copy had
already succeeded fire-and-forget.
Fix: setClipboard() now returns { sequence, success } where success =
native-fired OR tmux-buffer-loaded OR osc52-emitted. copyNative()
returns a boolean telling setClipboard whether a native attempt was
made. /copy only shows 'failed' when literally no path was taken.
2. Dashboard keybinding
Before: Ctrl+C for copy on non-Mac (Ctrl+Shift+C for paste).
That swallows SIGINT when a stale selection is present and breaks
the xterm/gnome-terminal/konsole/Windows-Terminal convention where
Ctrl+C in a terminal emulator is always SIGINT. The real bug was
that clipboard writes lost user-gesture through OSC-52 round-trips,
which the direct writeText already fixes.
Fix: revert copyModifier to Ctrl+Shift+C on non-Mac. Direct
writeText in the keydown handler preserves user gesture. term.write
Escape replaced with term.clearSelection() (works without relying
on TUI input mode).
3. Error toast text
Before: 'see HERMES_TUI_DEBUG_CLIPBOARD' — tells users how to
debug but not how to fix.
Fix: point users at HERMES_TUI_FORCE_OSC52=1 first (the actual
escape hatch), mention the debug var second.
The cherry-picked approach serialized the UI-shaped transcript on the Node
side, producing a third JSON format alongside cli.py save_conversation and
tui_gateway session.save. Simpler to call the existing session.save method,
which already writes the canonical agent history (raw OpenAI messages +
model) to an absolute-path file.
- /save still short-circuits before the slash worker
- Empty transcript -> 'no conversation yet'
- No active session -> 'no active session - nothing to save'
- Otherwise: rpc('session.save', {session_id}) and echo back the file path
- Tests updated to assert RPC contract; new test covers the no-sid case
- accept forwarded Cmd+C for selection copy in SSH sessions even when Hermes runs on Linux
- keep local Linux Alt+C from acting as copy and update TUI hotkey hints for remote shells
- run the requested ui-tui lint+format pass and include resulting formatting updates
- guard text-measure cache eviction key in hermes-ink so ui-tui type-check stays green
Inline diff segments were anchored relative to assistant narration, but the
turn details pane still rendered after streamSegments. On completion that put
the diff before the tool telemetry that produced it. When a turn has anchored
diff segments, commit the accumulated thinking/tool trail as a pre-diff trail
message, then render the diff and final summary.
Extends SECTION_DEFAULTS so the out-of-the-box TUI shows the turn as
a live transcript (reasoning + tool calls streaming inline) instead of
a wall of `▸` chevrons the user has to click every turn.
Final default matrix:
- thinking: expanded
- tools: expanded
- activity: hidden (unchanged from the previous commit)
- subagents: falls through to details_mode (collapsed by default)
Everything explicit in `display.sections` still wins, so anyone who
already pinned an override keeps their layout. One-line revert is
`display.sections.<name>: collapsed`.
Copilot review on #14968 caught that the early returns gated on the
global `detailsMode === 'hidden'` short-circuited every render path
before sectionMode() got a chance to apply per-section overrides — so
`details_mode: hidden` + `sections.tools: expanded` was silently a no-op.
Three call sites had the same bug shape; all now key off the resolved
section modes:
- ToolTrail: replace the `detailsMode === 'hidden'` early return with
an `allHidden = every section resolved to hidden` check. When that's
true, fall back to the floating-alert backstop (errors/warnings) so
quiet-mode users aren't blind to ambient failures, and update the
comment block to match the actual condition.
- messageLine.tsx: drop the same `detailsMode === 'hidden'` pre-check
on `msg.kind === 'trail'`; only skip rendering the wrapper when every
section resolves to hidden (`SECTION_NAMES.some(...) !== 'hidden'`).
- useMainApp.ts: rebuild `showProgressArea` around `anyPanelVisible`
instead of branching on the global mode. This also fixes the
suppressed Copilot concern about an empty wrapper Box rendering above
the streaming area when ToolTrail returns null.
Regression test in details.test.ts pins the override-escapes-hidden
behaviour for tools/thinking/activity. 271/271 vitest, lints clean.
The activity panel (gateway hints, terminal-parity nudges, background
notifications) is noise for the typical day-to-day user, who only cares
about thinking + tools + streamed content. Make `hidden` the built-in
default for that section so users land on the quiet mode out of the box.
Tool failures still render inline on the failing tool row, so this
default suppresses the noise feed without losing the signal.
Opt back in with `display.sections.activity: collapsed` (chevron) or
`expanded` (always open) in `~/.hermes/config.yaml`, or live with
`/details activity collapsed`.
Implementation: SECTION_DEFAULTS in domain/details.ts, applied as the
fallback in `sectionMode()` between the explicit override and the
global details_mode. Existing `display.sections.activity` overrides
take precedence — no migration needed for users who already set it.
Rebase-artefact cleanup on this branch:
- Restore `voice.status` and `voice.transcript` cases in
createGatewayEventHandler plus the `voice` / `submission` /
`composer.setInput` ctx destructuring. They were added to main in
the 58-commit gap that this branch was originally cut behind;
dropping them was unintentional.
- Rebase the test ctx shape to match main (voice.* fakes,
submission.submitRef, composer.setInput) and apply the same
segment-anchor test rewrites on top.
- Drop the `#14XXX` placeholder from the tool.complete comment;
replace with a plain-English rationale.
- Rewrite the broken mid-word "pushInlineDiff- Segment" in
turnController's dedupe comment to refer to
pushInlineDiffSegment and `kind: 'diff'` plainly.
- Collapse the filter predicate in recordMessageComplete from a
4-line if/return into one boolean expression — same semantics,
reads left-to-right as a single predicate.
Copilot review threads resolved: #3134668789, #3134668805,
#3134668822.
Visual polish on top of the segment-anchor change: diff blocks were
butting up against the narration around them. Tag diff-only segments
with `kind: 'diff'` (extended on Msg) and give them `marginTop={1}` +
`marginBottom={1}` in MessageLine, matching the spacing we already
use for user messages. Also swaps the regex-based `diffSegmentBody`
check for an explicit `kind === 'diff'` guard so the dedupe path is
clearer.
