docs+ci(predictive-echo): CI package-suite step, invariants, changeset

ci.yml runs the xterm-zerolag-input suite (Layers 1-3) after the root
npm ci (workspaces hoisting; no separate install). CLAUDE.md and
architecture-invariants.md rewrite the codex echo story: predictive
write-through with the wire-neutrality, separate-bundle, composer-gate,
baseY and blank-neutral invariants spelled out; the single-source section
now covers both vendor bundles and why their entry points differ.
Changeset: minor for aicodeman + xterm-zerolag-input.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.changeset/c4baa514.md

@@ -0,0 +1,14 @@
+---
+"aicodeman": minor
+"xterm-zerolag-input": minor
+---
+
+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.
+- Tests: 52 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.

.github/workflows/ci.yml

@@ -91,6 +91,14 @@ jobs:
         # Safe in CI: TmuxManager no-ops all shell commands under VITEST (test/setup.ts).
         run: npm run test:ci
 
+      - name: Run xterm-zerolag-input package tests
+        # Layers 1-3 of the predictive-echo suites (unit laws, fixture replay,
+        # seeded fuzz): deterministic, no browser, no live server. Depends on
+        # the ROOT `npm ci` above — workspaces hoist the package's vitest into
+        # the root node_modules; do not add a separate install here.
+        run: npx vitest run
+        working-directory: packages/xterm-zerolag-input
+
 # Note: The browser-driven mobile suite (test/mobile/**) is excluded from CI —
 # it needs a live server + chromium + environment-specific PNG baselines.
 # Run it locally/manually. All other tests run via the `test` job above.

CLAUDE.md

@@ -129,7 +129,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 - **Model choice flows via `settings.local.json`, NOT `--model` or env** — the App Settings **Claude Model** picker (`claudeModel` in `settings.json`) is read by `session-ui.js` at session create (wins over the legacy 1M-Opus toggles `opusContext1m`/`opusContext1mEnabled`), sent as the `modelOverride` payload field, and `updateCaseModel()` (`hooks-config.ts`) writes/deletes the `model` key in `<case>/.claude/settings.local.json`. This is the intended exception to the envOverrides rule above: model legitimately lives in `settings.local.json` (a soft default — in-session `/model` still works); env vars do not
 - **Multi-CLI prefix discipline** — env-var prefix is CLI-specific (`CLAUDE_CODE_*` vs `OPENCODE_*` vs `CODEX_*` vs `GEMINI_*` vs `ANTIGRAVITY_*`) and the `ALLOWED_ENV_PREFIXES` allowlist in `schemas.ts` enforces this. Gemini additionally allowlists the **broad `GOOGLE_*`** namespace (intentional: Vertex AI auth needs `GOOGLE_CLOUD_PROJECT`/`GOOGLE_APPLICATION_CREDENTIALS`/`GOOGLE_GENAI_USE_VERTEXAI`; it is the loosest allowlist entry, affecting only the user's own spawned CLI). When adding a setting, decide which CLI(s) it applies to and gate the env export accordingly. Never blanket-forward all prefixes. Resolver design pattern: `docs/opencode-integration.md`
 - **Zod `.optional()` rejects `null`** — accepts `undefined` only. When the frontend builds a request body with `JSON.stringify`, an explicit `null` field is preserved on the wire and fails validation with `INVALID_INPUT`. Convert `null` → `undefined` before stringifying (e.g. `field: value ?? undefined`), or declare the schema `.nullish()`. This has caused real shipped bugs twice
-- **`xterm-zerolag-input` is single-source** — the local-echo overlay source lives ONLY in `packages/xterm-zerolag-input/src/`, and is bundled into the **gitignored** `src/web/public/vendor/xterm-zerolag-input.js` (dev, by `scripts/postinstall.js`) and `dist/.../vendor/` (prod, by `scripts/build.mjs`). `app.js` only **consumes** it via `new LocalEchoOverlay(terminal)`; there is no inline copy. So: change the package source, then rerun the bundle step (`npm install` for dev, `npm run build` for prod). **Never hand-edit `app.js` for overlay behavior, and never commit the gitignored vendor bundle.** Always test on mobile after touching it. → [architecture-invariants#xterm-zerolag-input-is-single-source](docs/architecture-invariants.md#xterm-zerolag-input-is-single-source), `docs/local-echo-overlay-plan.md`
+- **`xterm-zerolag-input` is single-source** — BOTH echo addons live ONLY in `packages/xterm-zerolag-input/src/`, bundled into TWO **gitignored** vendor files: `vendor/xterm-zerolag-input.js` (buffer overlay, entry `zerolag-input-addon.ts`) and `vendor/xterm-predictive-echo.js` (codex write-through, entry `predictive-echo-addon.ts`) — dev by `scripts/postinstall.js`, prod by `scripts/build.mjs`. `app.js`/terminal-ui.js only **consume** them via `new LocalEchoOverlay(terminal)` / `new PredictiveEchoOverlay(terminal)`; there is no inline copy. So: change the package source, then rerun the bundle step (`npm install` for dev, `npm run build` for prod). **Never hand-edit `app.js` for overlay behavior, and never commit the gitignored vendor bundles.** Always test on mobile after touching it. → [architecture-invariants#xterm-zerolag-input-is-single-source](docs/architecture-invariants.md#xterm-zerolag-input-is-single-source), `docs/local-echo-overlay-plan.md`
 - **Default bind is loopback-only; non-loopback without a password starts but warns** — the server defaults to `--host 127.0.0.1`. Binding non-loopback (`--host`/`-H`/`CODEMAN_HOST`) without `CODEMAN_PASSWORD` starts anyway but prints a loud warning; `--allow-unauthenticated-network` / `CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK=1` acknowledges it. ⚠️ The production systemd unit passes no `--host`, so prod binds **localhost only**: reach it via `tailscale serve`/tunnel to `127.0.0.1`. A loopback bind is reachable through a same-host tunnel but NOT by a browser hitting the box's LAN IP. `install.sh` is separate and prompts for the binding (defaulting to LAN + a password), and preserves the existing binding on re-runs. → [architecture-invariants#default-bind-and-the-non-loopback-warning-path](docs/architecture-invariants.md#default-bind-and-the-non-loopback-warning-path), `docs/security-architecture.md`
 - **Instance isolation / multi-instance attach danger** — the data dir (`~/.codeman`) and tmux socket (`tmux -L codeman`) are PROCESS-WIDE and shared by every Codeman on the machine, derived from `CODEMAN_INSTANCE` via `src/config/instance.ts`. ⚠️ A 2nd instance on the SAME socket **discovers and attaches PTYs to the first instance's live sessions**, resizing and mutating them. `$HOME` isolation is NOT enough because tmux is system-global. To run two instances, give each a distinct `CODEMAN_INSTANCE` (scopes dir + socket together), or set `CODEMAN_TMUX_SOCKET` + `CODEMAN_DATA_DIR` individually; `scripts/run-beta.sh` does this for a beta alongside prod. **Any new `~/.codeman/...` path MUST go through `dataPath()`**, never `join(homedir(), '.codeman', …)`. → [architecture-invariants#instance-isolation-and-the-multi-instance-attach-danger](docs/architecture-invariants.md#instance-isolation-and-the-multi-instance-attach-danger)
 - **node-pty's macOS `spawn-helper` ships without `+x`** (issues #6, #204): `node-pty@1.1.0` publishes `prebuilds/darwin-<arch>/spawn-helper` as mode 0644, and macOS launches every PTY through it, so a stock macOS install fails every session start with `Error: posix_spawnp failed.` **Linux can never reproduce it**: `spawn-helper` is an `OS=="mac"` gyp target and node-pty ships no Linux prebuild, so node-gyp always emits an executable helper there. ⚠️ Look in **`prebuilds/<platform>-<arch>/`**, not just `build/Release/`, which does not exist on macOS. Repair is a chmod, never a mandatory rebuild (that would require Xcode CLI tools and deletes `prebuilds/` before compiling): `npm run fix:node-pty` chmods every helper then proves it by really opening a PTY. `spawnPtyWithHelperRepair()` (`utils/node-pty-repair.ts`) wraps every `pty.spawn()` in `session.ts` and self-heals a broken install on the first failure. → [architecture-invariants#node-ptys-macos-spawn-helper-must-be-executable](docs/architecture-invariants.md#node-ptys-macos-spawn-helper-must-be-executable)
@@ -198,7 +198,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 **Docker cases**: a case can point at a **container**, with any of the five CLI backends running inside it. Like remote-SSH this is a **LOCATION OVERLAY on cases, never a sixth `SessionMode`**. Exactly one long-lived container **per case**, shared by all its sessions, so killing a session kills only that session's in-container tmux and **never** `docker stop` while siblings remain. The workspace is a real host dir bind-mounted at the **same absolute path**, which is what keeps file-routes/watchers on real host bytes and makes the in-container transcript projHash match the host. Credentials are **seeded** (RO mount, copied into the container once) rather than shared RW, so in-container CLIs never write refreshed tokens back to the host, and bind mounts are excluded from `docker commit` so exports stay secret-free. **NEVER a create-time `-e` for secrets, NEVER `--privileged`, NEVER the docker socket.** Config drift is detected via a label hash and a drifted launch is REFUSED rather than silently launched with stale config. ⚠️ On the loopback-only prod bind a container cannot reach 127.0.0.1, so in-container hooks need `CODEMAN_DOCKER_BRIDGE_HOOKS=1`; otherwise idle detection falls back to output-based. → [architecture-invariants#docker-cases](docs/architecture-invariants.md#docker-cases), `docs/docker-cases.md` (user guide), `docs/docker-cases-plan.md` (design)
 
-**External CLI modes (OpenCode, Codex, Gemini, Antigravity)**: `isExternalCliMode()` in `session.ts` gates Claude-specific behavior off (Ralph tracker, BashToolParser, token/CLI-info parsing, ❯-prompt readiness); these CLIs render their own TUIs, so readiness is output stabilization instead. All four **require tmux with no direct PTY fallback**, because secrets are injected via socket-scoped `tmux setenv` and never on the spawn command line. ⚠️ `run*()` in `session-ui.js` MUST unwrap the `{success,data}` envelope; reading the raw shape silently breaks the run. ⚠️ **The local-echo overlay is DISABLED for codex sessions** (`_updateLocalEchoState` in terminal-ui.js, same branch as shell): codex's composer reacts per keystroke ("/" pops a live-filtering picker, arrows edit server-side state, the composer grows as it wraps), so buffer-until-Enter starved it into issues #218/#219/#220/#222. Codex also **drops keystrokes that share a PTY read with a bracketed paste**, so flushed text and the paste sequence must go out as separate delayed writes (mirroring the Enter branch's delayed `\r`). Tests: `test/local-echo-codex-gating.test.ts`. → [architecture-invariants#external-cli-modes-opencode-codex-gemini](docs/architecture-invariants.md#external-cli-modes-opencode-codex-gemini)
+**External CLI modes (OpenCode, Codex, Gemini, Antigravity)**: `isExternalCliMode()` in `session.ts` gates Claude-specific behavior off (Ralph tracker, BashToolParser, token/CLI-info parsing, ❯-prompt readiness); these CLIs render their own TUIs, so readiness is output stabilization instead. All four **require tmux with no direct PTY fallback**, because secrets are injected via socket-scoped `tmux setenv` and never on the spawn command line. ⚠️ `run*()` in `session-ui.js` MUST unwrap the `{success,data}` envelope; reading the raw shape silently breaks the run. ⚠️ **Codex sessions use PREDICTIVE WRITE-THROUGH echo, never the buffer overlay** (`_localEchoPolicy` in `_updateLocalEchoState`, terminal-ui.js): codex's composer reacts per keystroke ("/" pops a live-filtering picker, arrows edit server-side state, the composer grows as it wraps), so buffer-until-Enter starved it into issues #218/#219/#220/#222 and stays disabled (`_localEchoEnabled` remains false for codex). Instead, `PredictiveEchoAddon` (separate `vendor/xterm-predictive-echo.js` bundle) paints each keystroke at the predicted cell while the wire path stays BYTE-IDENTICAL: the onData hook (`_predictHookOnData`) is a plain statement with no `return`, so control always falls through into the untouched send path — pinned by vm and E2E byte-identity tests. Predictions reconcile against the parsed buffer and only while the cursor sits on the measured composer row (`isCodexComposerRow`, `/^› /`). Codex also **drops keystrokes that share a PTY read with a bracketed paste**, so flushed text and the paste sequence must go out as separate delayed writes (mirroring the Enter branch's delayed `\r`). Tests: `test/local-echo-codex-gating.test.ts`, `test/codex-predictive-echo.test.ts` (E2E vs real codex), `packages/xterm-zerolag-input/test/codex-replay.test.ts`. → [architecture-invariants#external-cli-modes-opencode-codex-gemini](docs/architecture-invariants.md#external-cli-modes-opencode-codex-gemini)
 
 **Run launch synchronization**: the Run entrypoint holds an in-flight lock and disables `#runBtn` for the whole launch (≥500ms), so a double click cannot create duplicate sessions with the same `w<n>-<case>` name. `_ensureCreatedSessionVisible()` runs before `selectSession()`, and `_onSessionCreated()` stays an idempotent upsert, so POST-first and SSE-first ordering both produce exactly one rendered tab. → [architecture-invariants#run-launch-synchronization](docs/architecture-invariants.md#run-launch-synchronization)
 

docs/architecture-invariants.md

@@ -22,7 +22,7 @@ Implementation detail extracted from `CLAUDE.md` so that file stays small enough
 
 **External CLI modes (OpenCode, Codex, Gemini, Antigravity)**: `isExternalCliMode()` in `session.ts` (`mode === 'opencode' || 'codex' || 'gemini' || 'antigravity'`) gates Claude-specific behavior — Ralph tracker, BashToolParser, token/CLI-info parsing, and ❯-prompt readiness detection are all skipped (these CLIs render their own TUIs; readiness = output stabilization instead). All four modes **require tmux — no direct PTY fallback** — because secrets are injected via `tmux setenv` (socket-scoped `${this.tmux()} setenv`, never on the spawn command line): OpenCode gets `OPENCODE_CONFIG_CONTENT` etc., Codex gets `OPENAI_API_KEY`/`CODEX_API_KEY`/`CODEX_HOME` (`setCodexEnvVars`), Gemini gets `GEMINI_API_KEY`/`GOOGLE_API_KEY`/`GOOGLE_CLOUD_PROJECT`/`GOOGLE_APPLICATION_CREDENTIALS`/`GOOGLE_GENAI_USE_VERTEXAI` etc. (`setGeminiEnvVars`, all in `tmux-manager.ts`). Codex specifics: command built by `buildCodexCommand()` (`--model`, `resume <id>`, `--dangerously-bypass-approvals-and-sandbox` from the `codexConfig` payload / `codexDangerouslyBypassApprovals` app setting; `renderMode` is schema-coerced to `'hybrid'`, the only supported mode). Gemini specifics: command built by `buildGeminiCommand()` (`--skip-trust` always, `--approval-mode <default|auto_edit|yolo|plan>` defaulting to `yolo` for parity with Claude's `--dangerously-skip-permissions`, `--model`, `--resume` from the `geminiConfig` payload); availability via `GET /api/gemini/status` — session/quick-start routes fail with `OPERATION_FAILED` + install hint (`npm install -g @google/gemini-cli`) when missing. Codex AND Gemini export `COLORTERM=truecolor` + unset `NO_COLOR` (other modes unset `COLORTERM`); Gemini joins `isAltScreenStripMode()` (Codex/Claude/Gemini are Ink TUIs that repaint inline → strip alt-screen/`3J` so scrollback survives). Codex availability via `GET /api/codex/status`. Antigravity specifics: command built by `buildAntigravityCommand()` (`--model`, `--conversation <id>` resume, `--dangerously-skip-permissions` from the `antigravityConfig` payload); availability via `GET /api/antigravity/status` — routes fail with `OPERATION_FAILED` + install hint (`curl -fsSL https://antigravity.google/cli/install.sh | bash`) when missing. Unlike the other three it is NOT an npm package (standalone binary, `~/.local/bin/agy`), which is why `docker/agent.Dockerfile` installs it with its own `--dir /usr/local/bin` step rather than in the `npm install -g` line, and why it does NOT join `isAltScreenStripMode()`. Frontend: run-mode dropdown → `runCodex()`/`runGemini()` in `session-ui.js` ("Run CX"/"Run GM" labels), App Settings → Codex CLI tab; Respawn/Ralph options are Claude-only, so session options open on the Summary tab for external CLI sessions. ⚠️ `run*()` MUST unwrap the `{success,data}` envelope (`(await res.json()).data.available` / `data.data.sessionId`) — reading the raw shape silently breaks the run. Tests: `test/run-mode-ui.test.ts` + `test/gemini-mode.test.ts` (vm-sandbox harness, no real DOM).
 
-**Codex input path (issues #218/#219/#220/#222)**: the local-echo overlay is **DISABLED for codex-mode sessions** (`_updateLocalEchoState` in terminal-ui.js, same branch as shell). Codex's composer is interactive per keystroke: typing "/" pops a live-filtering command picker (#222 was "picker never appears" because the "/" sat in the overlay until Enter), the composer grows/rewraps as it fills (#220: a long typed prompt existed ONLY in the overlay DOM, so codex never grew the composer), arrows and Ctrl+Backspace edit server-side state (#218: arrows were forwarded to an EMPTY composer while the typed text sat pending; the `\x08` control-char flush then left the overlay stateless so `\x7f` was swallowed as "nothing to remove"), and pastes arrive bracketed (#219: `terminal.paste()` wraps in `\x1b[200~..201~`, which the multi-byte-ESC branch forwarded WITHOUT flushing pending text, so the paste landed before it). The shared overlay branch (claude/gemini/opencode still buffer) gained three fixes: bracketed pastes flush pending text first, composer nav keys (`isComposerNavKey` allowlist in `CodemanTerminalInput` — arrows/Home/End/Delete/PgUp/PgDn incl. modifiers, deliberately excluding DA/CPR/DSR query responses) flush and hand the session to **pass-through** (plain PTY echo until Enter/Ctrl+C, because after cursor movement the append-only overlay cannot track edits), and a backspace that finds no overlay state is FORWARDED instead of swallowed. ⚠️ **Codex drops keystrokes that arrive in the same PTY read as a bracketed paste** (upstream `bottom_pane/paste_burst.rs` holds rapid chars for paste classification; verified against codex 0.147.0 by writing `hello\x1b[200~PASTED\x1b[201~` into the tmux client PTY in one write → composer shows only `PASTED`, while a 100ms gap yields `helloPASTED`), so the flush sends the typed text immediately and delays the paste sequence by 80ms — the same two-phase shape as the Enter branch's delayed `\r`. Related protocol fact: xterm.js sends `0x08` for Ctrl+Backspace, which codex's keymap binds to delete-ONE-char (`ctrl(Char('h'))`); real word-delete needs the kitty CSI-u encoding (`\x1b[127;5u`), which xterm.js 6.0.0 cannot emit (kitty support lands in 6.1.0-beta) — an upstream limitation, not a Codeman bug. E2E technique: codex 0.147 reaches its composer with any dummy key in `$CODEX_HOME/auth.json` (`{"OPENAI_API_KEY":"sk-test-..."}`), so a real TUI can be driven headlessly (envOverrides `CODEX_HOME` rides the `CODEX_*` allowlist) without real credentials. Tests: `test/local-echo-codex-gating.test.ts` (vm harness: nav-key classifier truth table, per-mode gating, flush helper, pass-through routing).
+**Codex input path (issues #218/#219/#220/#222)**: codex-mode sessions use **predictive write-through echo, never the buffer overlay**. The buffer overlay stays disabled exactly as 1.12.2 left it (`_updateLocalEchoState` in terminal-ui.js, same branch as shell; `_localEchoEnabled` remains false for codex), and the additive `_localEchoPolicy` field selects `'predict'` for codex when `localEchoEnabled` is on. Codex's composer is interactive per keystroke: typing "/" pops a live-filtering command picker (#222 was "picker never appears" because the "/" sat in the overlay until Enter), the composer grows/rewraps as it fills (#220: a long typed prompt existed ONLY in the overlay DOM, so codex never grew the composer), arrows and Ctrl+Backspace edit server-side state (#218: arrows were forwarded to an EMPTY composer while the typed text sat pending; the `\x08` control-char flush then left the overlay stateless so `\x7f` was swallowed as "nothing to remove"), and pastes arrive bracketed (#219: `terminal.paste()` wraps in `\x1b[200~..201~`, which the multi-byte-ESC branch forwarded WITHOUT flushing pending text, so the paste landed before it). The shared overlay branch (claude/gemini/opencode still buffer) gained three fixes: bracketed pastes flush pending text first, composer nav keys (`isComposerNavKey` allowlist in `CodemanTerminalInput` — arrows/Home/End/Delete/PgUp/PgDn incl. modifiers, deliberately excluding DA/CPR/DSR query responses) flush and hand the session to **pass-through** (plain PTY echo until Enter/Ctrl+C, because after cursor movement the append-only overlay cannot track edits), and a backspace that finds no overlay state is FORWARDED instead of swallowed. ⚠️ **Codex drops keystrokes that arrive in the same PTY read as a bracketed paste** (upstream `bottom_pane/paste_burst.rs` holds rapid chars for paste classification; verified against codex 0.147.0 by writing `hello\x1b[200~PASTED\x1b[201~` into the tmux client PTY in one write → composer shows only `PASTED`, while a 100ms gap yields `helloPASTED`), so the flush sends the typed text immediately and delays the paste sequence by 80ms — the same two-phase shape as the Enter branch's delayed `\r`. Related protocol fact: xterm.js sends `0x08` for Ctrl+Backspace, which codex's keymap binds to delete-ONE-char (`ctrl(Char('h'))`); real word-delete needs the kitty CSI-u encoding (`\x1b[127;5u`), which xterm.js 6.0.0 cannot emit (kitty support lands in 6.1.0-beta) — an upstream limitation, not a Codeman bug. E2E technique: codex 0.147 reaches its composer with any dummy key in `$CODEX_HOME/auth.json` (`{"OPENAI_API_KEY":"sk-test-..."}`), so a real TUI can be driven headlessly (envOverrides `CODEX_HOME` rides the `CODEX_*` allowlist) without real credentials. **Predictive write-through echo invariants** (the codex echo mode, `PredictiveEchoAddon` in `packages/xterm-zerolag-input`): (1) the onData hook `_predictHookOnData` is a PLAIN STATEMENT between the buffer block and Normal Mode — no `return`, try/catch-wrapped, never touches `_pendingInput` — so the wire path is byte-identical with the predictor active, absent or throwing (pinned at vm level and by an end-to-end trace-equality E2E); (2) it ships as a SEPARATE bundle `vendor/xterm-predictive-echo.js` so the zerolag bundle stays byte-identical, and a missing/broken bundle degrades codex to plain 1.12.2 echo (`typeof PredictiveEchoOverlay !== 'undefined'` guard); (3) predictions paint only while the cursor sits on the measured composer row (`isCodexComposerRow`, `CODEX_COMPOSER_ROW_RE = /^› /` — matches the empty-composer placeholder, typing, and the slash picker; rejects modal rows and 2-space wrapped continuation rows, the #220 ghost zone, which deliberately fall back to real echo); (4) reconciliation reads the PARSED buffer with `baseY + row` (xterm's `cursorY` is baseY-relative; `viewportY` only coincides while scrolled to bottom), confirms prefix-only on cell match PLUS cursor advance, cascades only on TWO consecutive foreign NON-BLANK passes (blanks are neutral: codex clears its placeholder on first echo), and TTL-bounds the rest; (5) the per-device `localEchoEnabled` toggle is the kill switch returning exact 1.12.2 behavior. Measured constants + fixtures: `docs/predictive-echo-plan.md`, recorded via `scripts/dev/record-codex-frames.mjs` through the production tmux+strip pipeline. Tests: `test/local-echo-codex-gating.test.ts` (vm harness: nav-key + predict classifier truth tables, policy matrix, wire-neutrality pins), `packages/xterm-zerolag-input/test/` (addon laws, real-fixture replay, seeded fuzz), `test/codex-predictive-echo.test.ts` (E2E vs real codex incl. byte-identity + 300ms-RTT).
 
 ### Remote sessions over SSH
 
@@ -275,7 +275,7 @@ Target: 20 sessions, 50 agent windows at 60fps. Limits in `src/config/`: termina
 
 ### xterm-zerolag-input is single-source
 
-**`xterm-zerolag-input` is single-source — edit the package, then rebuild the bundle** — the local-echo overlay source lives ONLY in `packages/xterm-zerolag-input/src/` (`zerolag-input-addon.ts`; also published to npm as a standalone library — see README "Published Packages"). It is bundled (esbuild → IIFE, with appended `window.LocalEchoOverlay` aliases) into the **gitignored** `src/web/public/vendor/xterm-zerolag-input.js` by `scripts/postinstall.js` (for dev/`tsx`) and into `dist/.../vendor/` by `scripts/build.mjs` (the `xterm-zerolag-input` esbuild step, for prod). `app.js` only **consumes** it via `new LocalEchoOverlay(terminal)` — there is NO inline copy to keep in sync. So: change behavior in the package source, then re-run the bundle step (`npm install` reruns postinstall; `npm run build` for prod); **never hand-edit `app.js` for overlay behavior or commit the gitignored vendor bundle**. A public-API break in the package still warrants a separate `xterm-zerolag-input` version bump in the changeset. Always test on mobile after touching it. See `docs/local-echo-overlay-plan.md`.
+**`xterm-zerolag-input` is single-source — edit the package, then rebuild the bundles** — BOTH echo addons live ONLY in `packages/xterm-zerolag-input/src/` (also published to npm as a standalone library — see README "Published Packages") and are bundled into TWO **gitignored** vendor files with DIFFERENT entry points: `vendor/xterm-zerolag-input.js` (buffer overlay, entry `zerolag-input-addon.ts`, `window.LocalEchoOverlay` alias) and `vendor/xterm-predictive-echo.js` (codex write-through, entry `predictive-echo-addon.ts`, `window.PredictiveEchoOverlay` alias) — dev by `scripts/postinstall.js` (reruns on `npm install`), prod by `scripts/build.mjs`. The separate entries are DELIBERATE: adding exports to the package's `index.ts` cannot change the zerolag bundle's bytes, which is what keeps predictive-echo changes structurally unable to regress buffer mode (verified sha256-identical at introduction). `app.js`/terminal-ui.js only **consume** the addons via `new LocalEchoOverlay(terminal)` / `new PredictiveEchoOverlay(terminal)` — there is NO inline copy to keep in sync. **Never hand-edit `app.js` for overlay behavior or commit the gitignored vendor bundles.** A public-API break in the package still warrants a separate `xterm-zerolag-input` version bump in the changeset. Always test on mobile after touching it. See `docs/local-echo-overlay-plan.md` (buffer mode) and `docs/predictive-echo-plan.md` (predict mode).
 
 ### node-pty's macOS spawn-helper must be executable