* fix(tui): keep Ink displayCursor in sync with fast-echo writes so cursor stops drifting
TextInput's fast-echo bypass writes characters directly to stdout to
avoid waiting on a React re-render for each keystroke. The hardware
cursor advances by text.length cells, but Ink's cached `displayCursor`
(the basis for the next frame's relative cursor-move preamble in
log-update) stayed unchanged. When ANY unrelated component re-rendered
between the fast-echo write and the deferred composer setCur/setParent
flush — status bar timer, streaming reasoning, etc. — the next frame's
preamble emitted a relative cursor move from a stale parked position
and the hardware cursor parked N cells offset from the actual caret.
Visible symptom: extra whitespace between the just-typed character and
the cursor block, intermittent, worse on long sessions during streaming.
Alt-screen was immune because frames begin with absolute CSI H.
This adds a small API in @hermes/ink:
- `Ink.noteExternalCursorAdvance(dx, dy?)` — bumps displayCursor if
set, otherwise seeds from frontFrame.cursor so the next preamble's
relative move correctly cancels the external advance. No-op on
alt-screen.
- `CursorAdvanceContext` + `useCursorAdvance()` hook to expose it.
TextInput then calls `noteCursorAdvance(text.length)` after the
fast-echo `stdout.write(text)` append, and `noteCursorAdvance(-1)`
after the fast-backspace `\b \b` sequence.
Tests: 4 new vitest cases pin the API contract (bumps when set, seeds
from frontFrame.cursor when null, alt-screen no-op, zero-delta no-op).
All 751 ui-tui tests pass; tests/test_tui_gateway_server.py (177) pass.
* fix(tui): also advance cursorDeclaration so fast-echo survives deferred React state
Copilot review on PR #26717 flagged a gap in the original fix:
TextInput's fast-echo path defers the React `cur` state update by
16ms (perf optimization that batches re-renders during heavy typing).
Inside that window, `useDeclaredCursor` still publishes a target
computed from the PRE-keystroke `cur` — `cursorLayout(display, cur,
columns)`. Advancing only `displayCursor` would let any unrelated
re-render in that 16ms window run onRender's cursor-park branch with
the stale declaration and visually undo the fast-echo's advance.
The fix is symmetric: `noteExternalCursorAdvance` now bumps BOTH
`displayCursor` (the log-update relative-move basis) AND, if non-null,
`cursorDeclaration.relativeX/Y` (the target the cursor parks at after
every frame). When React finally flushes `setCur`, `useDeclaredCursor`
publishes a fresh declaration that supersedes our bumped one — exactly
what we want.
Adds two new vitest cases covering both halves:
- active declaration advances in lock-step with displayCursor
- null declaration stays null (no spurious bump)
All 753 ui-tui tests pass; tests/test_tui_gateway_server.py (177) pass.
Closes review threads:
PRRT_kwDOPRF1G86ChKtD (textInput.tsx:1016 fast-echo append)
PRRT_kwDOPRF1G86ChKtF (textInput.tsx:924 fast-backspace)
PRRT_kwDOPRF1G86ChKtG (ink-cursor-advance.test.ts:57 missing coverage)
* fix(tui): make fast-echo survive TextInput rerenders + alt-screen (Copilot round 2)
Round 2 of PR #26717 review. Three real holes Copilot flagged after the
initial cursorDeclaration bump:
1. alt-screen early-return skipped BOTH halves of the notifier. But the
default TUI wraps the composer in <AlternateScreen> — that IS the
production path. CSI H resets log-update's relative-move basis, but
the alt-screen park branch uses absolute CUP =
`rect.x + decl.relativeX`, so a stale declaration there still parks
the cursor at the pre-keystroke caret. Fix: skip ONLY the
displayCursor half on alt-screen; still bump cursorDeclaration.
2. TextInput's own rerender could clobber the Ink-level bump. The fast-
echo path defers setCur by 16ms; if a parent state change rerenders
TextInput in that window, the layout effect inside useDeclaredCursor
reads the stale React `cur` state and re-publishes a declaration at
the OLD column. Fix:
`cursorLayout(display, curRef.current, columns)` — read the always-
up-to-date ref, not the deferred state. useMemo dropped (compute is
cheap, single-line wrap-text in the common case).
3. Tests bypassed the production wiring. Added two structural tests:
- `still advances cursorDeclaration on alt-screen` in the Ink-level
suite, asserting displayCursor stays put but the declaration
advances by the delta.
- `textInputCursorSourceOfTruth.test.ts` pins three structural
invariants: layout reads curRef.current, never the bare `cur`
state, and the fast-echo stdout.write calls remain paired with
noteCursorAdvance(±N). Source-grep invariants > flaky Ink mount
tests for this kind of regression.
757/757 ui-tui tests pass (+3 over round 1). type-check clean. lint
introduces zero new errors on touched files. tests/test_tui_gateway_server.py
(177) pass.
Closes review threads:
PRRT_kwDOPRF1G86ChOG2 (ink.tsx alt-screen guard)
PRRT_kwDOPRF1G86ChOG9 (textInput.tsx fast-backspace rerender window)
PRRT_kwDOPRF1G86ChOHC (textInput.tsx fast-append rerender window)
PRRT_kwDOPRF1G86ChOHJ (alt-screen test asserts wrong invariant)
PRRT_kwDOPRF1G86ChOHP (missing integration-style coverage)
* fix(tui): reject fast-backspace at soft-wrap boundary (Copilot round 3)
PR #26717 round 3. Copilot caught two real things:
1. `\b \b` cannot move the terminal cursor onto the previous visual
row across a soft-wrap boundary. When the caret sits at visual
column 0 of a wrapped row (e.g. value 'hello ' at width 6 →
cursorLayout produces (line 1, col 0)), backspace would leave the
physical cursor in place while the logical caret moves up to the
end of the previous visual line. `noteCursorAdvance(-1)` would then
feed Ink a wrong delta. Fix: `canFastBackspaceShape` now takes the
composer width and rejects when `cursorLayout(value, cursor, columns).column === 0`.
The fast path falls through to the normal Ink render, which
correctly lays out the new caret position. The PR-description
inconsistency about alt-screen is fixed in a separate gh pr edit.
Adds 4 new tests in textInputFastEcho.test.ts pinning the rejection at
exact-multiple wrap boundaries plus a positive control inside a
wrapped line and a back-compat case where `columns` is omitted.
761/761 ui-tui tests pass. type-check / lint clean. 177/177 Python
tests/test_tui_gateway_server.py pass.
Closes review threads:
PRRT_kwDOPRF1G86ChxE5 (textInput.tsx:933 wrap-boundary regression)
* fix(tui): polish doc + tests after Copilot round 4
Three polish points Copilot raised:
1. canFastBackspaceShape doc comment overstated the legacy contract —
said it conservatively rejects potential wrap boundaries when
columns is omitted, but the implementation actually skips the
wrap-boundary check entirely. Reworded to make the legacy behavior
explicit and warn callers not to rely on protection they don't get.
2. ink-cursor-advance.test.ts rationale comment for the
'advances cursorDeclaration in lock-step' case still referenced
the pre-fix `cursorLayout(display, cur, columns)` expression. Now
accurately describes the current source of truth — `curRef.current`
in textInput.tsx — and explains the window the bump is bridging.
3. Removed the three `__get*ForTest` accessors from Ink. The test
file already cast the instance to inspect private state in the
couple of tests that needed declaration mutation; the rest now use
a small `peek(ink)` helper that does the same cast for reads. No
test-only API surface ships in production.
761/761 ui-tui tests pass. type-check clean. lint introduces zero new
errors on touched files. 177/177 tests/test_tui_gateway_server.py pass.
Closes review threads:
PRRT_kwDOPRF1G86Ch23W (canFastBackspaceShape doc accuracy)
PRRT_kwDOPRF1G86Ch23f (stale test rationale)
PRRT_kwDOPRF1G86Ch23p (test-only API surface in production)
* fix(tui): tighten doc + add dy test coverage (Copilot round 5)
Two polish points from round 5:
1. canFastBackspaceShape doc had two paragraphs that conflicted —
the main 'Additionally rejects when the physical cursor sits at
visual column 0' was stated unconditionally, then the columns-param
paragraph qualified that it only happens when columns is passed.
Reworked into clear 'When supplied / When omitted' branches with a
concrete example value ('hello ' returns true without columns even
though it would be unsafe at width 6). No more inconsistency.
2. Added a test asserting cursorDeclaration.relativeY advances when dy
is non-zero. Existing tests exercised dy on displayCursor only.
Newlines in fast-echoed text don't currently hit the bypass
(canFastAppendShape rejects '\n'), but dy is part of the public
notifier contract and must propagate symmetrically with dx so
future callers get a fully-implemented contract.
762/762 ui-tui tests pass (+1). type-check / lint / build clean.
Closes review threads:
PRRT_kwDOPRF1G86Ch6Sz (doc inconsistency)
PRRT_kwDOPRF1G86Ch6TE (missing dy coverage on declaration)
* fix(tui): doc polish (Copilot round 6)
Four small but valid points:
1. textInputCursorSourceOfTruth.test.ts used bare 'fs'/'path'/'url'
imports; the rest of ui-tui consistently uses the 'node:' prefix
(see src/__tests__/useSessionLifecycle.test.ts, src/lib/editor.test.ts).
Switched to node:fs / node:path / node:url to match convention.
2. CursorAdvanceContext.ts type-level doc described only displayCursor.
The notifier intentionally also mutates the active cursorDeclaration
and that's the only part that matters on alt-screen. Reworked the
doc into a two-part 'updates both' summary with the alt-screen
asymmetry called out explicitly.
3. use-cursor-advance.ts hook doc had the same problem. Same fix —
document both pieces of state, both screen modes.
4. App.tsx onCursorAdvance prop comment was incomplete. Same fix —
describe both state updates and the screen-mode asymmetry.
No behavior change. 762/762 ui-tui tests pass. type-check / lint /
build clean.
Closes review threads (auto-resolved on PR but valid critiques):
PRRT_kwDOPRF1G86Ch926 (node: prefix on built-in imports)
PRRT_kwDOPRF1G86Ch92_ (use-cursor-advance.ts doc)
PRRT_kwDOPRF1G86Ch93H (CursorAdvanceContext.ts type doc)
PRRT_kwDOPRF1G86Ch93J (App.tsx prop comment)
* tui: make URLs clickable + hover-highlight in any terminal
Problem
-------
URLs printed by `hermes --tui` were not clickable in basic macOS Terminal.app.
Cmd+click did nothing, the cursor didn't change shape — like nothing was
detected — even though arrow buttons and other Box onClick handlers worked
fine.
Root cause
----------
Two layers of dead plumbing:
1. `<Link>` only emitted the underlying `<ink-link>` (which carries the
hyperlink metadata into the screen buffer) when `supportsHyperlinks()`
said yes. On Apple_Terminal that's false, so the per-cell hyperlink
field stayed empty, so `Ink.getHyperlinkAt()` had nothing to return on
click. The visible underline was just decorative.
2. `Ink.openHyperlink()` calls `this.onHyperlinkClick?.(url)`, but
`onHyperlinkClick` was never assigned anywhere in the codebase. The
click pipeline (`App.tsx → onOpenHyperlink → Ink.openHyperlink`) ran
but bailed silently on the optional chain.
Bonus discovery: even when wired up, there was no hover affordance —
terminal apps can't change the system mouse cursor, so users had no
visual signal that a cell was clickable. Arrow buttons in the chrome
worked because they had explicit `<Box onClick>` styling; inline link
URLs didn't.
Fix
---
- `Link.tsx`: always emit `<ink-link>` regardless of terminal capability.
The renderer's `wrapWithOsc8Link` already gates the actual OSC 8 escape
on `supportsHyperlinks()` further down — so terminals that don't
understand OSC 8 still don't see the escape, but the screen-buffer
metadata (which the click dispatcher reads) is now populated everywhere.
- `ink.tsx + root.ts`: add `onHyperlinkClick?: (url: string) => void` to
`Options` / `RenderOptions`, wire it to the existing `Ink.onHyperlinkClick`
field in the constructor.
- `src/lib/openExternalUrl.ts`: small platform-aware opener using
`child_process.spawn` with arg-array (no shell) — http(s) only, rejects
`file:`, `javascript:`, `data:`, etc., so a hostile model can't trigger
arbitrary local handlers via `<Link url="file:///...">`. Detached + stdio
ignore so closing the TUI doesn't kill the browser and Chrome stderr
doesn't leak into the alt screen.
- `entry.tsx`: pass `onHyperlinkClick: openExternalUrl` to `ink.render`.
- `hyperlinkHover.ts` + Ink hover wiring: track the URL under the pointer
in `Ink.hoveredHyperlink`, update it from `dispatchHover`, and inverse-
highlight every cell of the matching link in the render-pass overlay
(same pattern as `applySearchHighlight`). This is the cursor-hover
affordance for clickable links — terminals don't expose cursor shape,
so we light up the link itself.
- `types/hermes-ink.d.ts`: add `onHyperlinkClick` to the `RenderOptions`
shim so consumers (`entry.tsx`) type-check against the new option.
Tests
-----
- `src/lib/openExternalUrl.test.ts` (15 cases): http(s) accepted; file/js/
data/mailto/ftp/ssh rejected; macOS open(1), Windows cmd.exe start with
empty title slot, Linux xdg-open dispatch; shell-metacharacter URLs
pass through unmolested as a single argv element; synchronous spawn
failure returns false.
Verified empirically in Apple Terminal 455.1 (macOS 15.7.3): clicking a
URL opens in default browser, hovering inverts the link cells, and
moving away clears the highlight. Full TUI suite: 713 passing, 0
type errors.
Reverts
-------
The earlier attempt that version-gated Apple_Terminal in
`supports-hyperlinks.ts` was based on a wrong assumption — Terminal.app
silently strips OSC 8 sequences but does not render them as clickable
hyperlinks. Reverted to the original allowlist.
* tui: address Copilot review — explorer.exe on win32 + comment fixes
- openExternalUrl: switch win32 from `cmd.exe /c start` to `explorer.exe`.
cmd.exe's `start` builtin reparses the URL through cmd's tokenizer, so
`&`, `|`, `^`, `<`, `>` either split the command or get reinterpreted —
breaking both the protocol-allowlist safety story AND plain http(s) URLs
with `&` in query strings. `explorer.exe <url>` invokes the registered
protocol handler directly with no shell.
- openExternalUrl.test.ts: rename the win32 test to reflect the new
contract and add two regression tests — one with `&|^<>` metachars,
one with the common analytics-URL `&` query-param pattern — both pinned
to single-argv-element delivery via explorer.exe.
- Link.tsx: fix misleading comment. OSC 8 escapes are emitted
unconditionally by the renderer (`wrapWithOsc8Link` in
render-node-to-output.ts, `oscLink` in log-update.ts). Non-supporting
terminals silently strip the sequence, which is why hover/click
affordance has to come from the in-process overlay rather than the
terminal's own link rendering.
Verified: 715/715 tests pass, type-check + build clean.
* tui: address Copilot review #2 — async spawn errors + hover scope + docs
1. openExternalUrl: attach a no-op `'error'` listener on the spawned
child BEFORE unref(). spawn() returns a ChildProcess synchronously
even when the binary is missing (ENOENT on xdg-open / explorer.exe),
unreachable, or otherwise unusable; the failure surfaces later as
an 'error' event. An unhandled 'error' on an EventEmitter crashes
Node, which would tear down the whole TUI. The listener is a
deliberate no-op — we already returned `true` synchronously and the
user just doesn't see the browser pop.
2. openExternalUrl.test.ts: add a regression test using a real
EventEmitter to simulate the async-error path. Pins both the
listener-attached contract and the "doesn't throw on emit" behavior.
Was 17/17, now 18/18.
3. ink.tsx dispatchHover: bypass `getHyperlinkAt()` and read
`cellAt(...).hyperlink` directly. `getHyperlinkAt` falls back to
`findPlainTextUrlAt` for cells without an OSC 8 hyperlink, but the
render-pass overlay (`applyHyperlinkHoverHighlight`) only matches on
`cell.hyperlink === hoveredUrl` — so plain-text URLs would burn
re-renders without ever producing the highlight. Hover is now a
strictly 1:1 fit for what the overlay can paint. Plain-text URLs
still get the click action via the existing dispatch path.
4. root.ts + ink.tsx doc comments: replace the misleading "typically
`open` / `xdg-open` / `start` shell" wording with the actual safe
recipe — argv-array spawn into `open` / `xdg-open` / `explorer.exe`,
with an explicit warning that `cmd.exe /c start` reparses the URL
through cmd's tokenizer and is unsafe + breaks `&`-query URLs.
Verified: 716/716 tests pass, type-check + build clean.
* tui: address Copilot review #3 — hover damage, alt-screen cleanup, opener allowlist
1. ink.tsx onRender: stop folding steady-state hover into hlActive.
hlActive forces a full-screen damage diff so previous-frame inverted
cells get re-emitted when the highlight set changes. The transition
IS the trigger — enter / leave / change-to-other-link. While the
pointer just sits on a link the painted cells don't change and the
per-cell diff handles the no-op. Folding the steady state in would
burn a full-screen diff on every frame. Added a
lastRenderedHoveredHyperlink tracker and gate the hlActive bump on
`hovered !== lastRendered`.
2. ink.tsx setAltScreenActive: clear hoveredHyperlink (and the tracker)
when toggling alt-screen state. Hover dispatch is alt-screen-gated,
so once we leave there's no path to clear it. Without this, remounting
<AlternateScreen> would paint a phantom hover from the previous
session until the next mouse-move arrived.
3. openExternalUrl.ts openCommand: allowlist linux + the BSD family for
xdg-open and return null for everything else (aix, sunos, cygwin,
haiku, etc.). Previously the default-fallback always returned
xdg-open, which made the caller's `if (!command) return false` dead
and yielded a misleading `true` on platforms that probably don't
have xdg-open. New tests cover the null path AND the
openExternalUrl-returns-false-without-spawning behavior.
Verified: 718/718 tests pass, type-check + build clean.
* tui: address Copilot review #4 — doc comment accuracy
1. openExternalUrl return-value doc: now lists all three false paths
(URL rejected / no opener for platform / synchronous spawn throw)
plus a note that async 'error' events still return true because the
spawn was attempted.
2. ink.tsx onHyperlinkClick field doc: clarifies the callback receives
either an OSC 8 hyperlink OR a plain-text URL detected by
findPlainTextUrlAt — App.tsx routes both into the same callback.
3. hyperlinkHover applyHyperlinkHoverHighlight doc: drops the misleading
'caller forces full-frame damage' promise. Caller decides; for hover
the current caller only forces full damage on transitions.
No behavior change. 718/718 tests pass.
* tui: address Copilot review #5 — lint fixes
1. ink.tsx: reorder `./hyperlinkHover.js` import before `./screen.js` to
satisfy perfectionist/sort-imports.
2. Link.tsx: drop unused `fallback` parameter destructuring + the
trailing `void (null as ...)` dead-statement (would trip
no-unused-expressions). Kept `fallback?: ReactNode` on the Props
interface as a documented compat shim so existing call sites still
compile, with a comment explaining why it's no longer wired up.
3. openExternalUrl.test.ts: replace `typeof import('node:child_process').spawn`
inline annotations (forbidden by @typescript-eslint/consistent-type-imports)
with a `SpawnLike` type alias backed by a real `import type { spawn as SpawnFn }`.
No behavior change. 718/718 tests pass, type-check clean, lint clean on
all modified files.
feat(gateway): refine Platform._missing_ and platform-connected dispatch
Restricts plugin-name acceptance to bundled plugin scan + registry
(no arbitrary string -> enum-pollution), pulls per-platform connectivity
checks into a _PLATFORM_CONNECTED_CHECKERS lambda map with a clean
_is_platform_connected method, and adds tests covering the checker map,
plugin platform interface, and IRC setup wizard.
Keep the latest prompt sticky while the viewport is in live assistant output beyond history, and clear stale sticky state at the real bottom using fresh scroll height.
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
- 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
- stringWidth: true LRU on cache hit (touch-on-read via delete+set) so
hot strings stay resident under long sessions; was insertion-order
FIFO before
- virtualHeights: include todos, panel sections, and intro version in
messageHeightKey so height-cache reuse correctly invalidates when
todo content / panel sections change
- virtualHeights: estimate trail+todos rows at todos.length+2 (or 2
collapsed) instead of the generic ~1-line fallback, so initial
virtualization offsets are closer to reality
- useInputHandlers: clearTimeout on unmount for scrollIdleTimer so
pending relaxStreaming() never fires after teardown
- render-node-to-output: drop unused declined.noHint counter from
scrollFastPathStats; it was always 0 (the "hint missing" branch is
outside the diagnostics block)
- perfPane / hermes-ink.d.ts: follow the noHint removal
- wheelAccel: replace ~/claude-code path comment with generic
attribution that doesn't reference a developer-local checkout
Adds an `evictInkCaches(level)` API that prunes the four hot module-level
caches (`widthCache`, `wrapCache`, `sliceCache`, `lineWidthCache`) with
either a half-keep LRU pass or a full clear. Wired into:
- memoryMonitor: half-prune on 'high', full drop on 'critical', before
the heap dump / auto-restart path. Gives long sessions a shot at
recovering RSS instead of hard-exiting.
- useSessionLifecycle.resetSession: half-prune so a /new session starts
with a half-warm pool and the prior session can resume cheaply.
Also: lineWidthCache now uses LRU half-eviction on overflow instead of a
full `cache.clear()`, matching the other three caches.
Comparison vs claude-code: both forks now share the same `prevScreen`
blit + dirty-cascade machinery in render-node-to-output. Their smoothness
came from sibling-memo discipline (every chrome pane memo'd so dirty
cascade doesn't disable transcript blit) — already in place in our
appLayout.tsx (TranscriptPane / ComposerPane / StatusRulePane all memo'd).
Alt-screen is not the cause; both use it. The remaining gap was per-row
CPU on width/wrap/slice, which the previous commit closed.
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.
Adds four fields to FrameEvent.phases and the matching profile
summary:
optimizedPatches post-optimize patch count (what's actually
written to stdout; the .patches field is
pre-optimize)
writeBytes UTF-8 byte count of the write this frame
backpressure true when Node's stdout.write returned false
(Writable buffer full — outer terminal can't
keep up)
prevFrameDrainMs end-to-end drain time of the PREVIOUS frame's
write, captured from stdout.write's 2-arg
callback. Reported on the next frame so the
measurement reflects "time until OS flushed
the bytes to the terminal fd", not "time until
queued in Node".
writeDiffToTerminal() now returns { bytes, backpressure } and
accepts an optional onDrain callback. Only attached on TTY with
diff; piped/non-TTY stdout bypasses flow control so the callback
would fire synchronously anyway.
Initial measurements under hold-wheel_up against 1106-msg session
(30Hz for 6s):
patches total 28,888
optimized total 16,700 (ratio 0.58 — optimizer cuts ~42%)
writeBytes 42 KB / 10s = 4.2 KB/s throughput
drainMs p50 0.14 ms terminal accepts bytes instantly
drainMs p99 0.85 ms
backpressure 0% of frames
This rules out the terminal-parse hypothesis — Cursor's xterm.js
drains our output in sub-millisecond time at only 4 KB/s. The
remaining lag has to be in the render pipeline, not the wire.
Profile output now includes the bytes+drain+backpressure lines to
keep this visible on every subsequent iteration.
Adds scrollFastPathStats counters to render-node-to-output.ts: captures
every time a ScrollBox's DECSTBM scroll hint is generated, records
whether the fast path took it (blit+shift from prevScreen) or declined,
and why. Exposed through hermes-ink's public exports and snapshotted on
every FrameEvent so the profiler harness can correlate decline reasons
with the actual patch/renderer cost per frame.
This is pure observation — no behaviour change. Preparing for the
virtual-history rewrite: the hypothesis was that our topSpacer/
bottomSpacer scheme disqualifies every scroll via heightDelta
mismatch, but the data shows the fast path is actually taken on most
scrolls (19/23 over a 6s PageUp hold through 1100 messages) — the
remaining steady-state renderer cost is Yoga tree traversal, not
the per-frame full redraw I initially suspected.
Declines that do happen correlate with React commits that changed the
mounted range mid-scroll (heightDelta=±3 to ±35). Those are the rarer
cases the virtualization rewrite still needs to address.
No test diffs — instrumentation-only. Build verified: `tsc --noEmit`
plus the full `npm run build` compiler post-pass pass cleanly.
Extends HERMES_DEV_PERF to capture the complete render pipeline, not
just React commits. Adds scripts/profile-tui.py to drive repeatable
hold-PageUp stress tests against a real long session.
perfPane.tsx:
Wires ink's onFrame callback (already plumbed through the fork) into
the same perf.log as the React.Profiler samples. Captures per-phase
timing (yoga calculateLayout, renderNodeToOutput, screen diff, patch
optimize, stdout write) plus yoga counters (visited/measured/cache-
Hits/live) and patch counts per frame. Events are tagged
{src: 'react'|'frame'} so jq can split them. logFrameEvent is
undefined when HERMES_DEV_PERF is unset, so ink doesn't even attach
the callback.
entry.tsx:
Passes logFrameEvent into render().
types/hermes-ink.d.ts:
Declares FrameEvent + onFrame on RenderOptions so the ui-tui side
type-checks against the plumbed-through ink option.
scripts/profile-tui.py:
New harness. Launches the built TUI under a PTY with the longest
session in state.db resumed, holds PageUp/PageDown/etc at a
configurable Hz for N seconds, then parses perf.log and prints
per-phase p50/p95/p99/max plus yoga-counter summaries. Zero deps
beyond stdlib. Exit 2 if nothing was captured (wiring broken).
Initial findings (1106-msg session, 6s PageUp hold at 30Hz):
- Steady state: 10 fps; renderer phase p99=63ms, write p99=0.2ms
- 4/107 heavy frames (>=16ms), all dominated by renderNodeToOutput
- One pathological 97ms frame with yoga measuring 70,415 text cells
and Yoga visiting 225k nodes — the cold-unmeasured-region hit
- Ink's scroll fast-path (DECSTBM blit from prevScreen) is
disqualified because our spacer-based virtual history doesn't
keep heightDelta in sync with scroll.delta, so every PageUp step
falls through to a full 2000-4800 patch re-render instead of ~40
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.
renderLink was discarding the URL entirely — it rendered the label as amber
underlined text and dropped the href. Result: Cmd+Click / Ctrl+Click did
nothing in any terminal, including Ghostty.
Now both markdown links `[label](url)` and bare `https://…` URLs are wrapped
in @hermes/ink's Link component, which emits OSC 8 (\\x1b]8;;url\\x07label\\x1b]8;;\\x07)
when supportsHyperlinks() returns true. ADDITIONAL_HYPERLINK_TERMINALS already
includes ghostty, iTerm2, kitty, alacritty, Hyper.
Autolinks that look like bare emails (foo@bar.com) now prepend mailto: in the
href so they open the mail client correctly.
Also adds a typed declaration for Link in hermes-ink.d.ts.
Additional TUI fixes discovered in the same audit:
1. /plan slash command was silently lost — process_command() queues the
plan skill invocation onto _pending_input which nobody reads in the
slash worker subprocess. Now intercepted in slash.exec and routed
through command.dispatch with a new 'send' dispatch type.
Same interception added for /retry, /queue, /steer as safety nets
(these already have correct TUI-local handlers in core.ts, but the
server-side guard prevents regressions if the local handler is
bypassed).
2. Tool results were stripping ANSI escape codes — the messageLine
component used stripAnsi() + plain <Text> for tool role messages,
losing all color/styling from terminal, search_files, etc. Now
uses <Ansi> component (already imported) when ANSI is detected.
3. Terminal tab title now shows model + busy status via useTerminalTitle
hook from @hermes/ink (was never used). Users can identify Hermes
tabs and see at a glance whether the agent is busy or ready.
4. Added 'send' variant to CommandDispatchResponse type + asCommandDispatch
parser + createSlashHandler handler for commands that need to inject
a message into the conversation (plan, queue fallback, steer fallback).
Two TUI fixes:
1. Hyperlinks are now clickable (Cmd+Click / Ctrl+Click) in terminals
that support OSC 8. The markdown renderer was rendering links as
plain colored text — now wraps them in the existing <Link> component
from @hermes/ink which emits OSC 8 escape sequences.
2. Skill slash commands (e.g. /hermes-agent-dev) now work in the TUI.
The slash.exec handler was delegating to the _SlashWorker subprocess
which calls cli.process_command(). For skills, process_command()
queues the invocation message onto _pending_input — a Queue that
nobody reads in the worker subprocess. The skill message was lost.
Now slash.exec detects skill commands early and rejects them so
the TUI falls through to command.dispatch, which correctly builds
and returns the skill payload for the client to send().
- hermes-ink: export `withInkSuspended()` + `useExternalProcess()` that
pause/resume Ink around an arbitrary external process (built on the
existing enterAlternateScreen/exitAlternateScreen plumbing)
- tui: `launchHermesCommand(args)` spawns the `hermes` binary with
inherited stdio, with `HERMES_BIN` override for non-standard launches
- tui: `/model` and `/setup` slash commands invoke the CLI wizards
in-place, then re-preflight `setup.status` and auto-start a session on
success — no more exit-and-relaunch to finish first-run setup
- setup panel now advertises those slashes instead of only pointing
users back at the shell
