A full-history load of a remote SSH session reads the scrollback from the
remote tmux in one bounded ssh round trip and splices it above the local
frame. A transport failure (ssh 255, timeout, unparseable output) starts a
30 s per-host back-off; a missing remote session is per-session only.
Conflict resolved in session-routes.ts: #602's remote scrollback read runs
before #601's capture helper and its alternate-screen fallback.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Conflicts resolved against #583 and #588:
- One history-depth field: #583's `historyLines` / `capturedHistoryLines`
(reported as `paneHistoryLines`) is kept, and #601's lines cut now reads it
instead of a second `capturedHistorySize`. #601's `alternateOn` /
`capturedAlternateOn` joins it, and the one display-message format string
ends `#{history_size} #{alternate_on}`.
- selectSession keeps #588's full=1 switch for panes with no scrollback, gated
off remote and Docker sessions, and #601's SHELL_LOAD_QUERY for shells.
- computeHistoryTruncationNotice names a line count when paneHistoryLines is
known (#583) and otherwise uses #601's remainder wording.
- docs: api-reference lists both historyLinesCut and paneHistoryLines; the
notice invariant keys on history_size while the shell's automatic load is
the one place alternate_on decides.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Review follow-ups for loading a shell from tmux's rendered history.
tmux adds no history while a pane is in the alternate screen, and a
nested tmux client (remote SSH and Docker cases, or tmux run by hand)
holds its pane there, so a full capture of it is one screen. The
display-message query that reads #{history_size} now also reads
#{alternate_on} (PaneCaptureOptions.capturedAlternateOn), and a request
carrying `alt=recording` (only SHELL_LOAD_QUERY sends it) is answered
the old way on such a pane: the visible frame over the tailed byte
recording. Agents, scroll pulls and Load full history are unchanged.
alternate_on cannot tell a nested tmux from vim or less, so a local
shell with one of those open takes the same fallback while it is open.
A full capture without `lines=` was reported as a 'tail' cut whenever
the pane held more than the configured ceiling (possible on tmux before
3.7), offering a Load full history that could never return more. The
cut is now reported only for a client bound below the ceiling.
The response carries `historyLinesCut` when that bound left lines in
tmux, and the banner then says earlier output may be retained instead
of naming the bytes a later tail cut, which undercount what tmux holds.
A bounded grid tile's shell load sends its own `lines=` (via
SHELL_LOAD_BASE_QUERY). CLAUDE.md, docs/architecture-invariants.md and
docs/api-reference.md describe the shell load, the cut report and the
fallback.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Review follow-ups for the remote scrollback read.
The 1.5 s slot-wait bound was checked inside the task, so it only fired
once runWithRemoteSshLimit() had already handed over a slot, after
everything queued ahead of it. runWithRemoteSshLimit() now takes
`maxWaitMs`: a waiter that times out leaves the queue, rejects with
RemoteSshSlotTimeoutError, never runs and never touches `active`. The
history read uses it, and a slot timeout does not back the host off.
Only a transport failure backs the host off now (ssh exit 255, a
timeout, a spawn error, output that is not the script's), via
classifyRemoteAliveExit(). A remote command failing is about that
session only. A live run against a real host showed a missing session
comes back as exit 0 with empty markers, because the `| tail -c` pipe
takes tail's exit status, so markers that arrived without a size are
also per-session.
fetchRemoteScrollback() takes an optional runner as a test seam; tests
now cover the bounded wait, each back-off class, its expiry, and the
masked missing-session case. A source pin covers the `-S 0` capture
branch. The two seams that can drop rows at the join (rows that scroll
during the round trip, a taller shared client) are documented in
docs/remote-sessions.md, and the limiter's header and the remote-ssh
invariants now name the history read as an ssh consumer.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A shell's automatic loads (tab select, dropped-output recovery, clear
terminal, a split/grid tile's load) replayed `session.terminalBuffer`,
the raw PTY recording, ahead of the visible frame. That recording holds
full-screen repaints (an ssh'd tmux, less, any TUI: cursor home, then the
rows joined by newlines, prompt on the last row) drawn for the pane
height of the moment. Replayed into a terminal with fewer rows, each
repaint's last newline scrolls and pushes its top row into scrollback,
so one line tmux holds once shows up dozens of times (26 copies in the
case that found this, after the pane went from 24 to 23 rows). Remote
SSH shell sessions hit it constantly: their inner tmux repaints often.
Shells now load a bounded window of tmux's rendered history instead
(`SHELL_LOAD_QUERY`: full=1&tail=1MiB&lines=10000), the same source the
scroll-to-top pull already used. `lines=10000` bounds the synchronous
capture-pane, measured at ~8 ms per 1000 lines (~0.1 s here vs ~0.8 s
for a 100k-line history). Because that bound is shallower than xterm's
scrollback, the server now reports a cut: the capture's existing
display-message query also reads `#{history_size}`
(`PaneCaptureOptions.capturedHistorySize`), and the route marks a full
capture `truncated` / 'tail' when tmux holds more than it read, so the
banner keeps offering Load full history and scroll-to-top keeps pulling
older lines. The byte cap still reports 'capped'. The banner no longer
names an amount it cannot know ("less than 1 KB more") for such a cut.
Agent sessions are unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The "Showing the most recent 1.0 MB of this session. 4.8 MB more may still
be retained." bar covered the top of the terminal on nearly every tab switch,
and for fullscreen claude panes it could never be acted on: `truncated`
measures the server's byte stream, while Load full history asks tmux, which
holds no scrollback for a pane that lives in the alternate screen.
- The capture reads `#{history_size}` in the cursor query it already makes
and the terminal route returns it as `paneHistoryLines`.
- A reported 0 hides the notice; a positive count replaces the byte gap in
the message.
- The notice is lazy: it appears once a wheel/touch gesture reaches the top
of the browser buffer (after the pull that gesture starts), leaves when
the user scrolls back to live output or switches tabs, and its dismissal
sticks per session until reload.
- formatHistoryBytes no longer prints "1024 KB" just under 1 MiB.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
A visible-frame capture repaints each row at an absolute position, counting up
to the pane's height. A terminal shorter than that clamps every address past its
own height onto its last line. The overflow rows then overwrite one another, and
the rows underneath are lost. Replaying a real 50-row capture into a 30-row
terminal rendered 28 lines of a 45-line command and drew the frame twice.
Nothing in the response said what height the frame was built for, so the client
could not detect this. A capture now reports the geometry it was really taken at
through `capturedGeometry` on `PaneCaptureOptions`, and the terminal response
carries it as `captureCols` and `captureRows`. When the captured pane is taller
than the terminal, or the size that produced the capture did not survive the
load, `selectSession` replays once at the size that stuck. `resizeRetry` caps
that at one attempt, so two competing fits cannot trade replays forever.
The retry re-arms the full-history flag only when the pass that ran had consumed
it. A tab switch takes the bounded tail, so its retry takes the tail too:
clearing the flag unconditionally would upgrade that switch into a fresh
scrollback capture the user never asked for, which the route's own comments put
at tens of megabytes.
What this repairs is a capture that won a race against the resize meant to
precede it. It does not repair a capture whose pane was too tall because
`Session.resize` declined the resize outright, which it does for a small
viewport while a desktop viewport's size claim is live. The retry re-sends the
same declined resize and captures the same pane, and `resizeRetry` then stops
it. Repairing that means changing who owns the pane size, which is a policy
question this does not touch. The reported geometry still helps there, because
the client can see the mismatch at all rather than being blind to it.
Follows #395, #396 and #397, which fixed the other ways the replayed frame and
the terminal could disagree.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Review of the previous commit found the guard inverted: the three skips keyed
on `?full=1`, which is only what the client asked for. When the capture comes
back null — ENOBUFS, a timeout, a vanished pane, or a session with no mux at
all — the reply falls back to the byte history, which IS a stream of
successive frames and still needs stripping. Gating on the request returned it
whole: measured at 82KB against 4KB for the same buffer without `full=1`. A
direct-PTY session takes that path on every first selection, not only during
an outage. The skips now key on `isFullCapture`, meaning a capture arrived.
Three further defects the same review surfaced, all on this path:
Keeping the trailing rows is only sound when a cursor move follows to count
back up from them. On the two branches where the cursor query fails there is
no move, so the caret was left at the bottom of the pane — worse than before.
The cursor is now read first and settles both decisions together.
The move is relative rather than absolute. `CUP` numbers rows from the top of
the browser's screen, so it is only right while the browser's row count equals
the pane's, and `resizeWindow` does not wait for tmux, so a capture can be
taken before a requested resize applies. Measured against real tmux with a
browser four rows shorter than the pane: the absolute move lands on a blank
row, the relative one lands on the caret's row.
An all-blank pane no longer reads as content. Retaining trailing rows and
appending a move made it non-empty, and the caller treats non-empty as "replay
this", so a blank screen would have replaced real history — the downgrade
`_replayWouldShrinkBuffer` refuses, arriving from the server side where that
guard cannot see it.
The documentation claimed one line per screen row. `-J` joins a hard-wrapped
row into its logical line, so that is false whenever any row wrapped: measured
at 10 lines for a 12-row pane. Both entries now say what actually holds, and
the stale "NOT repositioned" contract in the mux interface is updated too.
Tests: the byte-history fallback is stripped, an empty capture leaves history
intact, and the extracted helpers are unit-tested directly rather than through
source-text matching. The slice window in the capture test is bounded at the
next method, having overrun into its neighbours.
Switching to a session left the caret one row below the composer's input
line, on the box border, and every cursor-relative update the CLI sent
afterwards was measured from the wrong row. Any fresh output repaired it,
because the CLI then repainted the whole frame.
Two things were wrong with the full-history replay, and they compound.
The capture never restored the cursor. The visible-frame path ends with an
absolute cursor move back to the pane's position; the linear path returned
its text and left the caret wherever the last character landed, which for an
agent CLI is the bottom-most row carrying text — the status line.
The rows it addressed did not line up with the pane's rows either. Four
transforms ran over the capture and each can delete a line: the trailing
blank rows were stripped, redraw-bloat stripping ran, the trim that cuts
everything above the Claude banner ran, and leading whitespace was removed.
All four are right for a byte stream of successive frames. A capture is the
rendered pane, one line per screen row, so each deletion shifted the frame
out from under the restored cursor.
The full-history path now appends the pane's own cursor position and keeps
every row, so row N of the reply is row N of the pane. The visible-frame and
tail paths are untouched.
Restoring the cursor is what makes row alignment load-bearing here, and
neither CLAUDE.md nor the architecture invariants said so — which is how
four line-deleting transforms accumulated on the path. Both now record it.
Verified against a live 315x59 pane: the reply carries 59 rows, its row 55
is the composer's input line matching tmux, and it ends with the cursor move
that lands there.
- Replace the 'missing ?tail means reload' overload with an explicit ?full=1
query param: the frontend's first buffer load after a page load (selectSession)
now requests full=1, tab switches keep ?tail=, and the legacy no-param callers
(response-viewer fallback, clearTerminal refresh) keep the cheap visible-frame
path — the COD-47 feature was previously unreachable from a real reload.
- When the full-history capture succeeds, return it ALONE instead of prepending
the byte buffer + \x1b[H\x1b[2J: the capture is the rendered superset of the
byte history, and ED2 clears only the viewport so the concat replayed the whole
conversation twice in xterm scrollback. The history+clear+frame concat stays
for the visible-frame/tab-switch path.
- Pass an explicit execSync maxBuffer for the full-history capture (configured
terminalBufferMaxBytes + slack) — the 1MB Node default ENOBUFS-killed exactly
the multi-MB captures the feature exists for; log ENOBUFS concisely instead of
dumping the truncated stdout.
- Bound the capture itself via -S -<N> derived from the configured tmux
history limit (was unbounded -S -), and add -J so lines hard-wrapped at the
capture-time pane width reflow in the browser xterm.
- Cap the concatenated buffer to terminalBufferMaxBytes EARLY (before the
regex normalization passes) so multi-MB captures don't stall the event loop
normalizing bytes that get sliced away.
- Tests: route tests updated for ?full=1 semantics (capture-alone response,
config-forwarded capture bounds, byte-history fallback, no-param requests
stay on the visible-frame path); source-scan tests cover the bounded -J -S -<N>
flags and explicit maxBuffer.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
A full page reload (GET /api/sessions/:id/terminal with no ?tail=) now captures
the ENTIRE tmux scrollback via capture-pane -p -e -S -, so users get back history
that scrolled off Codeman's byte buffer. Tab switches (?tail=N) keep the fast
visible-frame capture.
- tmux-manager capturePaneBuffer/captureActivePaneBuffer take { fullHistory }:
full-history returns raw linear scrollback (skips the single-screen
formatPaneSnapshot repaint, which would clip multi-screen history).
- /terminal selects full-history on full reload, visible on tail; caps the
payload at the configured terminalBufferMaxBytes (keeps most-recent bytes,
line-aligned) and returns source/fullSize/truncated metadata.
Verified: tsc 0, tmux-capture-full-history 5/5, session-routes 68/68.
Caveat: lines tmux already evicted past its history-limit can't be recovered.
Ludo Fourrage