# Phase 288: REPL mode (design-first, file-mode unaffected)

Status: ✅ P0–P3 complete (2025-12-25) / ⏳ 288.1 next

Goal: Add an interactive REPL for Nyash while keeping file mode semantics unchanged and keeping the language SSOT stable.

SSOT:
- REPL spec: `docs/reference/language/repl.md`

## Scope

- CLI entry: `hakorune --repl` / `-i`
- REPL commands: `.help`, `.exit/.quit`, `.reset`
- Fail-Fast: undefined reads are errors
- File mode: no behavior changes (quick smokes remain green)

## Completed (P0–P3)

- P0: SSOT doc established/updated (`docs/reference/language/repl.md`)
- P1: CLI entry point (`--repl` / `-i`)
- P2: REPL session state isolated (Box-first; runtime-value based)
- P3: Minimal UX and docs polish

## Next (Phase 288.1)

The MVP intentionally deferred these:

- Session variable **persistence across lines** (bridge session → compilation/runtime)
- Expression auto-display + `_` last-value binding
- Multi-line input handling (continuations)

Entry: `docs/development/current/main/phases/phase-288/P1-INSTRUCTIONS.md`