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.
Two new skills under skills/software-development/ for real breakpoint-driven
debugging from the terminal:
- node-inspect-debugger: node --inspect / --inspect-brk, node inspect REPL,
CDP scripting via chrome-remote-interface, attaching to running Node
processes (SIGUSR1), ui-tui-specific recipes, Vitest under debugger,
CPU profiles + heap snapshots.
- python-debugpy: pdb quick reference, breakpoint() workflow, pytest --pdb
(with xdist caveat for scripts/run_tests.sh), post-mortem, debugpy for
remote/attach, remote-pdb as the agent-friendly alternative to DAP,
recipes for tui_gateway/_SlashWorker/subprocess debugging.
Before: change code → build → run profile → manually compare to
mental model of last run. After: `--loop` watches ui-tui/src and
packages/hermes-ink/src for .ts(x) changes, rebuilds on change,
re-runs the same scenario, prints a side-by-side A/B diff against
the previous iteration — so each edit's impact is quantified
instantly. Ctrl+C to stop.
Also added:
--save LABEL saves metrics snapshot to /tmp/perf-<LABEL>.json
--compare LABEL diffs the current run vs that snapshot
--extra-flag X pass-through to node dist/entry.js (prepping for
--no-fullscreen below)
key_metrics() flattens a full run into scalar numbers across
frames, React commits, and per-phase timings. format_diff() prints
a table with ↑/↓ markers denoting regressions vs improvements based
on whether the metric is lower-is-better (p99, max, patches, drain)
or higher-is-better (fps, gaps_under_16ms).
Run-to-run noise on static code is ~5-15% on most metrics — big
signal (>30% change on renderer_p99 / fps) cuts through cleanly.
Useful both for validating a single fix and for detecting subtle
regressions during the wheel-accel port.
Usage during the next perf session:
# one-shot with a baseline for later comparison
scripts/profile-tui.py --seconds 6 --hold wheel_up --save pre-accel
# after porting the wheel handler
scripts/profile-tui.py --seconds 6 --hold wheel_up --compare pre-accel
# continuous iteration
scripts/profile-tui.py --seconds 6 --hold wheel_up --loop
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.
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.
User observation: "it doesn't scroll line by line/row by row."
Was right. Two places hardcoded big deltas:
1. WHEEL_SCROLL_STEP = 6 (config/limits.ts)
Each wheel event scrolled 6 rows. A mechanical wheel notch emits
3-5 events → 18-30 rows per click, which visually teleports past
content instead of smooth-scrolling it. Drop to 1. Trackpads
emit 50-100 events per flick — at step=1 that's still a fast flick
(a whole viewport in one flick) but each intermediate frame is
visible. Porting claude-code's wheel accel state machine is the
right next step if this feels sluggish on precision scrolls.
2. pageUp/pageDown = viewport - 2 (useInputHandlers.ts)
Full-viewport jumps replace the entire screen — no visual
continuity, can't scan content — AND land right at Ink's fast-path
threshold (`delta < innerHeight`), which disqualifies the DECSTBM
blit on every press. Half-viewport keeps 50% continuity AND
drops well under the threshold. Two presses still cover the same
total distance.
Profiled against the 1106-msg session, holding the key at 30Hz for
6s:
wheel_up (step 6 → 1):
frames 142 → 163 (+15%)
throughput 10.7 → 15.8 fps (+48%)
patches tot 53018→ 36562 (-31%)
gap p50 5ms → 16ms (actual rendering ~60fps now)
<16ms frames 93 → 76
16-33ms 82 → 76
hitches 3 → 1
pageUp (viewport-2 → viewport/2):
throughput 10.7 → 9.5 fps (same ballpark — smaller delta × same
event rate = less total scroll)
Ink's proportional drain caps at `innerHeight - 1` per frame to keep
the DECSTBM fast path firing. With these smaller deltas every event
comfortably fits under that cap, so fast-path hit rate goes up and
patch volume per frame drops — the measured 31% reduction in total
patches-sent correlates with users perceiving smoother scrolling
because the outer terminal (VS Code / xterm.js / tmux) isn't drowning
in ANSI between paints.
Tests/type-check/build clean; 352 tests pass.
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.
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
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).
Every command in COMMAND_REGISTRY (/btw, /stop, /model, /help, /new,
/bg, /reset, ...) is now a first-class Slack slash command instead of
a /hermes <subcommand>. Users get the same autocomplete-driven slash
picker experience Slack users expect and that Discord and Telegram
already provide.
Previously Slack registered ONE native slash (/hermes) and split on
the first word, so typing /btw in Slack's composer got 'couldn't find
an app for /btw' because the workspace manifest never declared it.
Changes
- hermes_cli/commands.py: slack_native_slashes() + slack_app_manifest()
generate a Slack manifest from the registry (canonical names +
aliases + plugin commands), clamped to Slack's 50-slash cap with
/hermes reserved as the catch-all.
- gateway/platforms/slack.py: single regex matcher dispatches every
registered slash to _handle_slash_command, which dispatches on
command['command']. Legacy /hermes <subcommand> keeps working for
backward compat with older workspace manifests.
- hermes_cli/slack_cli.py + hermes_cli/main.py: new 'hermes slack
manifest' command prints/writes a full manifest (display info,
OAuth scopes, event subs, socket mode, slash commands) ready to
paste into 'Create from manifest' or Features → App Manifest.
- hermes_cli/setup.py: _setup_slack() now writes the manifest up-front
and points users at the 'From an app manifest' flow; also offers
to refresh the manifest on reconfigure for picking up new commands.
- Tests: 14 new tests covering native-slash dispatch (/btw, /stop,
/model), legacy /hermes <sub> compat, manifest structure, and
telegram<->slack parity (every Telegram command must also register
as a Slack slash). Existing /hermes-registration test updated to
assert the new regex matches /hermes, /btw, /stop, /model, /help.
- Docs: slack.md gains a 'Slash Commands' section + Option A manifest
flow in Step 1; cli-commands.md documents 'hermes slack manifest'.
Users pick up the new slashes by running 'hermes slack manifest --write'
and pasting into Features → App Manifest → Edit in their Slack app
config, then Save (Slack prompts for reinstall if scopes changed).
The Docker terminal-backend docs said 'each session starts a long-lived
container', implying a fresh container per chat session. That hasn't been
true for a while: for the top-level agent, task_id defaults to 'default'
and the container is cached in _active_environments for the lifetime of
the Hermes process. /new, /reset, and switching sessions all reuse the
same container. Only delegate_task subagents and RL rollouts get isolated
containers keyed by their own task_id.
skills/feeds/ only contained a category-marker DESCRIPTION.md with no
actual skills in it. Removing the directory and the 'feeds' -> 'Feeds'
display-label mapping in website/scripts/extract-skills.py (the only
other reference in the repo).
* fix(tui): call maybe_auto_title for TUI sessions (#15961)
The maybe_auto_title() helper is called from cli.py and gateway/run.py
but was never wired into tui_gateway/server.py, so every session started
via 'hermes --tui' landed in state.db with an empty title. Evidence from
the issue reporter: 0/154 TUI sessions titled vs 91/383 CLI.
Mirror the CLI/Gateway pattern: after emitting message.complete, when the
turn finished cleanly, fire-and-forget title generation using the session
key, user prompt, agent response, and current history.
Fixes#15949.
Co-authored-by: math0r-be <math0r-be@github.com>
* chore(release): map math0r-be placeholder email in AUTHOR_MAP
---------
Co-authored-by: math0r-be <math0r-be@github.com>
* fix(/branch): redirect session_log_file and expose branch sessions in list
Two bugs when using /branch:
1. cli.py _handle_branch_command updated agent.session_id but not
agent.session_log_file, so all messages written after branching
landed in the original session's JSON file and the branch never
got its own session_{id}.json on disk.
Fix: mirror the compression-split path (run_agent.py:7579) and
update session_log_file immediately after changing session_id.
2. hermes_state.py list_sessions_rich filtered out every session
with parent_session_id IS NOT NULL to hide sub-agent runs and
compression continuations. Branch sessions share this column, so
they became invisible to `hermes sessions list` and `sessions browse`.
Fix: also include branch children — those whose parent ended with
end_reason='branched' AND whose started_at >= parent.ended_at
(the same timing condition that get_compression_tip uses to
distinguish continuations from live-spawned subagents).
Fixes#14854
Co-Authored-By: Octopus <liyuan851277048@icloud.com>
* chore(release): map octo-patch placeholder email in AUTHOR_MAP
---------
Co-authored-by: octo-patch <octo-patch@github.com>
Co-authored-by: Octopus <liyuan851277048@icloud.com>
