# xterm-zerolag-input

## 0.3.0

### Minor Changes

- 55bff4a: Zero-lag predictive echo for Codex sessions (mosh-style write-through prediction).

  Codex's per-keystroke composer forced 1.12.2 to disable the local-echo overlay (issues #218/#219/#220/#222), leaving Codex typing at full round-trip latency on remote links. This release adds a second echo mode instead of re-enabling the first: every keystroke still goes to the PTY exactly as before (byte-identical wire behavior, pinned by vm-level and end-to-end trace-equality tests), while the new `PredictiveEchoAddon` in `xterm-zerolag-input` 0.2.0 paints the predicted glyph at the predicted cell. When the real echo lands, the prediction is confirmed and its span removed (an invisible swap); mispredictions self-heal via a two-pass mismatch cascade and a TTL.
  - Reconciliation reads the parsed terminal buffer, never the raw stream: full-line redraws, ECH gap painting and tmux's in-place deltas all converge to the same cells. Confirmation requires the cell match PLUS a cursor advance, so placeholder glyphs and identical repaints never false-confirm; blank cells are neutral (codex clears its placeholder on the first echo).
  - Predictions paint only while the cursor sits on the measured Codex composer row (`/^› /`, codex-cli 0.147): trust/approval modals and wrapped continuation rows get no ghosts, deliberately falling back to real echo.
  - Ships as a SEPARATE `vendor/xterm-predictive-echo.js` bundle: the existing zerolag bundle is byte-identical (sha256-verified), and a missing or broken bundle degrades Codex to exact 1.12.2 behavior. The per-device `localEchoEnabled` toggle is the kill switch.
  - Claude/Gemini/OpenCode/Antigravity keep buffer mode untouched; shell stays off.
  - A post-build adversarial review added the anchor-hold rule: after an unpredicted wire edit (backspace into echoed text, cleared input, IME text commits) new predictions hold until the next parsed write, so a stale displayed cursor can never mis-anchor a run.
  - Tests: 55 new package tests including replay suites driven by fixtures recorded from a real codex TUI through the production tmux+strip pipeline (`scripts/dev/record-codex-frames.mjs`) and a 500-iteration seeded fuzz; new vm policy/wire-neutrality suites; a 10-scenario Playwright E2E against real codex covering the #218/#219/#220/#222 retests, byte-identity, and a simulated 300ms-RTT run. The package test suite now runs in CI.

## 0.2.0

### Minor Changes

- **New addon: `PredictiveEchoAddon`, mosh-style write-through prediction.** The second echo mode for per-keystroke TUIs (OpenAI Codex's composer, live pickers) that buffer-until-Enter starves. Every keystroke is sent by the consumer immediately and unchanged; the addon paints the predicted glyph at the predicted cell and reconciles against the PARSED terminal buffer: confirmation requires the cell match plus a cursor advance past the record, foreign non-blank content on two consecutive passes cascades a drop, blank cells are neutral, a TTL bounds everything, and scroll/resize/sustained cursor moves clear the run. Visual-only by construction; it cannot gate, delay or rewrite input.
  - Anchor-hold rule: after an unpredicted wire edit (backspace into echoed text, cleared input, an IME text commit) new predictions hold until the next parsed write, so a stale displayed cursor can never mis-anchor a run (worst case: exactly one unpredicted keystroke).
  - New exports: `PredictiveEchoAddon`, `PredictiveEchoOptions`, `PredictionState`, plus the long-intended `charCellWidth` / `stringCellWidth` helpers.
  - `XtermTerminal` type gains OPTIONAL members (`buffer.active.cursorX/cursorY`, `getLine().getCell?`, `onWriteParsed?`, `onResize?`). Additive only: existing consumers and mocks are unaffected.
  - IIFE build exposes `window.PredictiveEchoAddon` and a self-activating `window.PredictiveEchoOverlay`, alongside the unchanged `ZerolagInputAddon` / `LocalEchoOverlay` globals.
  - Tests: 52 new (30 addon-law specs, renderer geometry, 6 replay suites driven by fixtures recorded from real codex 0.147 through tmux + the production strip, and a 500-iteration seeded fuzz with per-op invariants). `@xterm/headless` as a devDependency; runtime dependencies remain zero.

## 0.1.8

### Patch Changes

- **Fixed: sessions failed to start on macOS with `Error: posix_spawnp failed.`** (issues #6 and #204)

  `node-pty@1.1.0` publishes its macOS prebuilt helper as `prebuilds/darwin-<arch>/spawn-helper` with mode 0644, i.e. no execute bit. macOS launches every PTY through that helper, so a stock install failed on every session start. The bug is macOS-only: `spawn-helper` is a mac-only gyp target and node-pty ships no Linux prebuild, so Linux always compiles a correctly-permissioned helper from source.

  The previous fix chmodded only `build/Release/spawn-helper`, which on macOS does not exist (the prebuild is used, so node-gyp never runs), and it derived that path from `require.resolve('node-pty')`, landing on `<pkg>/lib/build/Release/...`. It was a no-op on every platform.
  - New `scripts/fix-node-pty.mjs` (also `npm run fix:node-pty`) chmods every `spawn-helper` it finds, in `build/Release`, `build/Debug` and each `prebuilds/*/`, then verifies the result by actually opening a PTY. A `require()` alone passes on a broken install, because the helper is only touched at spawn time.
  - `postinstall` no longer force-rebuilds node-pty from source on Node 22+. That step needed Xcode command line tools, cost 30-120s on every install, and deleted the `prebuilds/` tree before compiling, so a Mac without a compiler was left with no working binary at all. A rebuild now happens only when the chmod plus spawn probe still fails, and the prebuilds tree is backed up and restored around it.
  - New `spawnPtyWithHelperRepair()` (`src/utils/node-pty-repair.ts`) wraps every `pty.spawn()` in `session.ts`, so an install that is already broken repairs itself on the first failed spawn and retries in-process instead of showing a dead session. Unrelated spawn errors are rethrown untouched; a second failure carries the `npm run fix:node-pty` hint.
  - `scripts/fix-node-pty.mjs` is now in the published `files` list, so global npm installs get the repair too.
  - Direct-PTY Claude spawns use the resolved absolute binary path (new `getClaudeBinaryPath()`) instead of the bare name `claude`, so a CLI installed outside the server's PATH still launches.

  Verified end to end on macOS 26.4 arm64: a stock `npm i` reproduces `posix_spawnp failed.`, and after the fix the same install spawns a PTY successfully with the prebuilds preserved.

  **Added: phone home screen (session overview)**

  Under 430px the "C" logo now opens a session overview (current sessions, past sessions, spaces) instead of the welcome overlay: on a small screen "which session needs me" beats "how do I start one". Rows resume a session in place, and "New session here" goes through the normal quick-start path so remote and Docker cases keep their routing. Per-device setting `mobileOverviewEnabled` (phones only, default ON) in App Settings. Tablet and desktop are unchanged.

  **Added: guided Tailscale setup in `install.sh`**

  The network-access prompt is now 3-way: Tailscale, LAN, or local-only. The Tailscale path binds loopback and walks through installing Tailscale, logging in, the operator grant, the tailnet HTTPS-certificates toggle, and `tailscale serve --bg <port>`, then verifies the result end to end with curl. That gives HTTPS on a real certificate with no app password and no `0.0.0.0` bind, which is also what PWA install and web push need. `install.sh tailscale` retrofits it onto an existing install, and `CODEMAN_TAILSCALE=1` presets the choice. Serve state is detected from `tailscale serve status --json`; the installer never runs `tailscale serve reset` and never touches serve mappings other than 443 to Codeman's port. README and `docs/security-architecture.md` updated to match.

  **Docs**: replaced a real tailnet hostname with placeholders in `docs/web-tabs-fixes-plan.md`.

  **xterm-zerolag-input**: npm description and keywords only, no code change.

## 0.1.7

### Patch Changes

- Fix a latent bug where a partial settings PUT silently reset live service state, and trim the `xterm-zerolag-input` README callout.
  - **`PUT /api/settings` no longer resets watchers on a partial body.** The three `toggleService` calls (subagent watcher, workflow-run watcher, image watcher) read the raw request body with `??` defaults, so every key a caller omitted was treated as "apply the default". A body of just `{statusLineTelemetry:true}` would START the subagent watcher and STOP the workflow and image watchers, undoing the persisted config. They now resolve from `merged` (persisted settings + incoming), the same convention the `tmuxHistoryLimit` branch in that handler already used, so any PUT reconciles services to the effective stored state. Nothing triggered this in practice because every shipped client sends a full settings payload rebuilt from the DOM, but it was a trap for the next partial-update caller.
  - **Regression test**: `test/routes/system-routes-settings-partial-put.test.ts` (4 cases) pins both directions, omitted keys preserve state and explicit keys still take effect. Verified to fail against the pre-fix handler.
  - **CLAUDE.md** records the rule under "Adding Features → App setting": anything acting on a setting in that handler must resolve from `merged`, never the request body.
  - **`xterm-zerolag-input` README**: removed the links line (getcodeman.com / install one-liner / star link) from the Codeman callout above the demo GIF. The callout keeps its links in the heading and body.

## 0.1.6

### Patch Changes

- Plan-usage chip now defaults ON on desktop, plus the reworked `xterm-zerolag-input` README.
  - **Plan-usage chip defaults ON (desktop).** The `showPlanUsageLimits` chip (live 5-hour and weekly plan usage from the Claude statusline) used to be opt-in and default OFF, so most users never saw it. Desktop now defaults ON; handhelds still default OFF so the phone header stays minimal and the `mobile-header-buttons-policy` guard keeps passing. Devices with an explicitly stored preference keep whatever they chose, so nobody's OFF gets overridden.
  - **One resolver behind the chip.** Added `planUsageChipEnabled()` in settings-ui.js and routed all three call sites through it: the App Settings checkbox, the chip's visibility, and the create-time `statusLineTelemetry` flag in session-ui.js. Those three had independent `?? false` / `=== true` defaults, and a chip revealed without the telemetry flag renders `—` forever, so a default flip on one site alone would have shipped a permanently empty chip.
  - **Cron button comment corrected.** The App Settings comment claimed "Cron button defaults ON" while the code, the template (`btn-cron--hidden`) and the CSS all default it OFF. Verified against a fresh browser profile: the button is hidden and its checkbox unchecked out of the box. Comment now matches, and states why the two halves stay consistent.
  - **Docs.** CLAUDE.md, `docs/architecture-invariants.md` and `docs/usage-limits-display-plan.md` updated for the new default and the single-resolver rule; the stale `styles.css` comment claiming the server strips the chip's hidden class at render was corrected (display is per-device, so the client reveals it).
  - **`xterm-zerolag-input` README rework** (0.1.5 shipped the content; this republishes with the graphic and promo changes): replaced the misaligned 8-line keystroke-flow diagram with a two-line stock-vs-zerolag contrast, added a Codeman callout above the demo GIF with links to getcodeman.com and the repo, and rewrote the Origin section so it argues the extraction story instead of repeating the promo.

## 0.1.5

### Patch Changes

- Rewrite the `xterm-zerolag-input` package README as a value-first document and correct the drift that had accumulated against the source.
  - Added the side-by-side phone demo GIF (`docs/images/zerolag-demo-20260728.gif`) as the hero image, referenced by absolute raw URL so it renders on npmjs.com as well as GitHub. The two-phone comparison shows 0ms local echo next to a 600ms-2.7s server echo on the same session.
  - New "Why this one" comparison table, an explicit list of target use cases (SSH web clients, cloud IDEs, mobile terminals, container consoles), and a bundle-size badge (6.1 kB gzipped, measured from the ESM build).
  - Corrected the test-count badge from 78 to the actual 175 tests across 5 files, in both the package README and the Published Packages section of the root README.
  - Removed the stale "Unicode/emoji rendered at single-cell width" limitation. CJK, fullwidth forms and emoji have had double-width rendering and visual-column positioning since the wide-character fix; the honest remaining caveat (per-code-point width summing over-counts ZWJ grapheme clusters) replaces it.
  - Documented the previously undocumented public `setPrompt()` method for switching prompt strategies at runtime, and the new "Wide characters (CJK, emoji)" integration section covering the optional `Unicode11Addon` path and the built-in range-table fallback.
  - Documented `backgroundColor: 'transparent'`, corrected the `foregroundColor` default, and updated the grid-alignment math to reflect visual-column positioning rather than character index.

  No source changes, docs only.

## 0.1.4

### Patch Changes

- Initial changelog entry for changesets-based versioning