Mosh-style write-through prediction: the consumer sends every keystroke
unchanged; the addon paints predicted glyphs and reconciles against the
parsed buffer. Confirm = cell match + cursor advance (placeholder-safe,
repaint-safe); two-pass mismatch cascade with neutral blanks (measured:
codex clears its placeholder on first echo); TTL bound; baseY-based line
reads; scroll/resize/off-row clears. Zero edits to zerolag-input-addon.ts.
Tests: 30 addon-law specs + renderer geometry (fake performance clock for
TTL/grace), 6 replay suites running the real algorithm through a real
@xterm/headless parser fed by the recorded codex fixtures, and a
500-iteration seeded fuzz with per-op span/record + grid invariants.
227 total, the pre-existing 175 untouched.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
1. Regex global flag safety — strip `g` flag before matching to prevent
lastIndex mutation and missing .index on match results
2. state.visible false before activate — null overlay no longer reports
visible: true
3. removeChar() returns 'pending' | 'flushed' | false instead of boolean
so consumers can distinguish whether to send backspace to PTY
4. removeChar() implements buffer detection cascade (step 3) — detects
existing prompt text when both pending and flushed are empty
5. RenderKey includes text content, not just length — prevents stale
renders when setFlushed() called with same count but different text
6. Remove dead `import type { Terminal }` from test file
7. Remove internal `FontStyle` from public exports
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Extract Claudeman's local echo overlay into a reusable xterm.js addon
at packages/xterm-zerolag-input/. Provides instant keystroke feedback
via a DOM overlay, eliminating perceived input latency over high-RTT
connections (SSH, mobile, cloud IDEs).
- Zero dependencies, compatible with xterm v5.x and @xterm/xterm v5.4+
- Configurable prompt detection (character, regex, or custom function)
- Flushed text tracking for tab-switch / deferred echo scenarios
- Per-character grid-aligned rendering matching xterm's canvas output
- 56 tests passing (prompt finder, overlay renderer, full addon lifecycle)
- Dual CJS/ESM build with full TypeScript declarations
Claudeman source is unchanged — migration to consume this lib is a
separate follow-up.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Codeman maintainer