Attribution (findings log 2026-07-03): main's onPtyData consumed ~93% of
the event loop under an agent-TUI flood, and the dominant term was
appendNormalizedToMultilineTailBuffer + finalizeRetainedTerminalRows
materializing ~2x tail-length row objects plus a per-row trailing-space
regex on every chunk — 0.888ms/chunk at the 2,000-line cap, on every
Claude-Code-shaped frame (cursor-up + erase-below).
The multiline algorithm now runs on a suffix window sized by the chunk's
maximum upward cursor excursion (plus the inherited redraw cursor and a
safety margin); the untouched prefix is shared by reference with a cheap
last-char trailing-space check to match the reference trim. Pathological
full-height cursor-ups fall back to the unwindowed implementation, which
is kept verbatim and exported as the reference for the 500-case
differential fuzz (retained-tail-redraw-window.equivalence.test.ts).
Micro-bench at a full 2,000-line tail: 0.888 -> 0.073 ms/chunk (12x).
1,415 runtime tests green, typecheck clean.
Co-authored-by: Orca <help@stably.ai>
DSR under load p50 161ms — the #7139/#7150 branch does not move the
under-load latency class. Expected in hindsight: DSR replies are ordered
within the output stream, so the metric measures output-queue depth;
cooperative drain paces input responsiveness but cannot reorder the queue.
Shrinking the queue itself (producer flow control, task 6) and raising
agent-tui throughput (task 9) are the levers for this number.
Co-authored-by: Orca <help@stably.ai>
Both isolate layers of the 51x agent-tui gap found in baseline-jul02:
bare @xterm/headless parses agent-tui at 103 MB/s and daemon Session
ingest (emulator + pending-output recording + fanout) at 103 MB/s —
on the byte stream the full Orca pipeline delivers at 2.0 MB/s.
Parser and daemon are exonerated; the loss is in main per-chunk
processing, delivery/ACK pacing, or renderer layers above xterm.
Co-authored-by: Orca <help@stably.ai>
Headline: Orca DSR latency under 1MB/s agent-TUI load is p50 134ms / p99 292ms
vs 0.45ms (Terminal.app) and 0.21ms (Ghostty). Idle latency is fine (0.69ms
p50) — the problem is queueing under load, not the pipeline hop. agent-tui
fenced throughput: Orca 2.0 MB/s vs Terminal.app 37 MB/s, Ghostty 78 MB/s.
Co-authored-by: Orca <help@stably.ai>
Run inside any terminal (Orca pane, iTerm2, Ghostty, Terminal.app, VS Code)
to measure its full byte path. DSR round-trip latency at idle and under a
paced agent-TUI load, plus fenced throughput over four deterministic
fixtures. The DSR fence forces 'all bytes parsed' before the clock stops so
xterm.js-class ingest queues can't flatter the result.
First piece of the terminal performance initiative's measurement rig.
Co-authored-by: Orca <help@stably.ai>
* Fix mirrored Codex relative config paths
Orca mirrors ~/.codex/config.toml into a managed CODEX_HOME before launching Codex. Relative path-valued Codex settings were then resolved from the runtime home instead of the user's real Codex home, which made config loading fail in Orca while the same CLI worked in a normal terminal. Rewrite known relative path settings to absolute paths rooted at the system Codex home while preserving runtime-owned trust sections.
* Dedupe Codex TOML line scanner and include path rewrite in CLI tsconfig
* Harden Codex config path rewrite and cover managed account homes
- Track multiline arrays in the shared TOML line scanner so array lines
are never mistaken for table headers or path keys
- Escape control characters and reject lone-surrogate unicode escapes so
the rewritten runtime config always stays valid TOML
- Extend the rewrite allowlist with profiles.* file settings and
debug.config_lockfile.* (both can abort Codex config loading)
- Rewrite relative paths when mirroring the canonical config into
managed account homes (codex login CODEX_HOMEs), anchoring WSL
accounts to the Linux-side ~/.codex with posix join semantics
---------
Co-authored-by: Neil <neil@stably.ai>
Playwright loads spec imports at collection time, and e2e specs import
terminal-module constants (e.g. terminal-attention.spec.ts pulls
POST_REPLAY_MODE_RESET from layout-serialization, whose chain reaches
replay-guard). The breadcrumb import added to the terminal modules made
that chain reach crash-diagnostics.ts, whose top-level import.meta.hot
and webview-registry import crash Playwright's transform
("ReferenceError: exports is not defined in ES module scope") — every
e2e shard failed at collection before running a single test.
Move recordRendererCrashBreadcrumb into crash-breadcrumb-recorder.ts
(type-only imports, no import.meta) and point the terminal modules and
their test mocks at it; crash-diagnostics re-exports for existing
callers. Full e2e suite collects again (262 tests / 94 files); unit
suites, typecheck, lint green. No runtime behavior change.
Co-authored-by: Orca <help@stably.ai>
Fixes#7116.
Use a forward-slash bare .cmd path for Claude/OpenClaude Windows hooks when the managed script path is Git-Bash-safe, avoiding the per-hook PowerShell startup overhead in the common case. Unsafe paths with spaces or shell metacharacters continue to use the encoded PowerShell launcher from #6078.
Keep Codex on its cmd.exe-safe fast path and leave the other agent integrations on the hardened encoded launcher.
Co-authored-by: Eren Çakar <hey@erencakar.com>
The 2 MB pending-output caps were flat, which risked dropping lines a
50k-row scrollback user would have retained. Both caps (main pendingData
and the renderer output queue) now derive from one shared policy:
max(2 MB, scrollbackRows x 120 chars) — 2 MB at the 5k default, 6 MB at
the 50k max. The main side reads the setting live via getSettings; the
renderer scheduler is configured where the terminal lifecycle already
reads the scrollback setting.
Every drop now records a rate-limited crash breadcrumb with dropped and
cap sizes (terminal_output_backlog_dropped in the renderer,
terminal_pending_output_dropped in main — no pty ids, session ids can
embed workspace paths). Field drop frequency and size decide whether the
cap constants need raising, replacing theory with data (#2836, #7017).
Backlog skip notices are now cap-agnostic since the limit varies.
Co-authored-by: Orca <help@stably.ai>
The previous stall watchdog blindly released the input guard after 10s.
If a replay were genuinely still parsing on a starved machine, that
early release could leak xterm's auto-replies into the shell — and into
agent TUIs, where a leaked ESC reads as the user pressing Escape.
Replace the blind release with a probe: when a completion looks
overdue, enqueue an empty write behind the replay. xterm parses writes
in order, so every outcome is provably safe:
- probe parses after the replay completion ran: normal release already
happened; probe is a no-op.
- probe parses but the replay completion never ran: all replay bytes
have parsed, no further auto-replies can exist — the completion was
genuinely lost. Release + breadcrumb.
- probe never parses (bounded wait): the pipeline is wedged, and a dead
parser can never emit auto-replies, so releasing cannot leak input.
Release + breadcrumb naming the pane as needing recovery.
While the probe is pending — a slow-but-alive replay — the guard now
HOLDS instead of releasing early; that case is pinned by a regression
test.
Co-authored-by: Orca <help@stably.ai>
Field evidence (Discord #performance / #2836): renderer memory climbs to
~1.5 GB and terminals freeze; a force reload does not help until memory
recovers. Two unbounded buffers matched that shape:
- Main-process pendingData grew by string concatenation without bound
while the renderer could not receive (frozen, starved, mid-reload) —
main-heap bloat a renderer reload cannot clear. Now capped at 2 MB per
PTY: past the cap the buffered bytes are dropped and the entry stays
O(1) until the renderer ACKs again, then a droppedOutput sentinel is
delivered and the pane repaints from the authoritative main-owned
buffer snapshot (existing hidden-output restore path) instead of
continuing a stream with a silent gap.
- The renderer output scheduler capped only hidden-pane backlogs; the
foreground path could queue a visible pane's flood without bound when
the drain could not keep up. The 2 MB cap now applies to every
foreground enqueue branch too, with a foreground-specific skip notice.
Verified: new main-side cap test (starve → flood → sentinel → normal
flow resumes), renderer sentinel-to-snapshot-restore test, two
foreground scheduler cap tests; full pty/terminal-pane/pane-manager
suites (1981 tests) and typecheck pass.
Co-authored-by: Orca <help@stably.ai>
A synchronous exception escaping xterm's WriteBuffer loop permanently
wedges that terminal: _innerWrite has no try/catch around the parse
action or the write-completion callback, the tail re-schedule never
runs, and write() only re-arms on an empty buffer. The pane stops
rendering and, if a replay was in flight, the replay guard latches and
pty-connection's onData silently eats every keystroke — matching the
field reports (Discord #performance, issue #2836: content visible,
shell alive, daemon output.log flat). Both vectors verified against
vendored xterm 6.1.0-beta.287 in xterm-write-buffer-stall.repro.test.ts.
Three layers of defense:
- Guard every write-completion callback Orca hands xterm at the two
choke points (writeForegroundTerminalChunk, writeBackgroundTerminalChunk),
with settle and onParsed guarded separately so a WebGL/renderer
failure during viewport settle cannot starve the replay-guard release.
- Guard all throwing-capable custom parser handlers (DA1, OSC 10/11,
CSI ?h/?l mode reports, OSC 52 clipboard, OSC 7 cwd), degrading a
throw to "not handled" — same escape class as
terminal-link-provider-guard.ts.
- Replay-guard watchdog: each engagement releases exactly once, from
xterm's completion or a 10s watchdog, so a lost completion (wedged
pipeline, disposed-terminal race) cannot latch the guard on a live
pane; replayIntoTerminalAsync resolves on either path so restore
chains cannot hang. Force-releases record a crash breadcrumb.
All guard trips record rate-capped crash breadcrumbs, so the next field
occurrence names the throwing stack instead of failing silently.
Co-authored-by: Orca <help@stably.ai>
Investigation harness for the frozen-terminal reports (Discord
#performance, issue #2836): pane shows content, shell alive, daemon
output.log flat while typing.
- e2e: renderer crash -> auto-reload recovery and three restart/restore
shapes (live daemon, SIGSTOP-wedged daemon, daemon killed between
launches), each probing input at both drop layers. Post-crash phases
drive the renderer from the main process because a crashed target
severs Playwright's CDP session even though the app recovers.
- e2e helpers: layer-discriminating probes (direct pty.write vs
transport input, plus pty:listSessions ownership-rebuild revival).
- unit repro: vendored xterm 6.1.0-beta.287 WriteBuffer permanently
wedges when a sync throw escapes a write-completion callback or a
custom parser handler (xterm-write-buffer-stall.repro.test.ts).
- unit repros for both silent input-drop layers: main drops writes for
a live PTY once ptyOwnership loses the id (revived by listSessions),
and the renderer transport stays unbound after a failed connect.
- pty.test.ts: unregister every leaked SSH provider id in afterEach so
module-level provider state cannot leak across tests.
Co-authored-by: Orca <help@stably.ai>
Run independent SSH relay bootstrap probes concurrently when the connection can safely support overlapping execs. Preserve the old sequential path for system SSH without reusable ControlMaster and for remotes that reject concurrent session channels.
* Verify Windows app executable signing
* Isolate Windows signing verifier tests
* Handle direct Windows installer extraction
---------
Co-authored-by: Neil <neil@stably.ai>
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