What Happened

Claude Code v2.1.91 ships with 10 documented power-up features accessible via the /powerup command. This analysis covers the five most impactful: @file referencing with line-number precision (e.g., @src/server.ts:142-180), three execution modes (auto/plan/manual) toggled via Shift+Tab, a two-tier undo system combining Esc-Esc for live interruption and /rewind N for checkpoint rollback with file restoration, a background task runner accessible via /tasks, and persistent project rules stored in CLAUDE.md at the repo root or ~/.claude/ for global config.

Why It Matters

For indie developers and small teams, these features address the three biggest productivity drains when using AI coding tools:

  • Token waste: Line-range references like @controllers/order.go:88-120 reduce context size and improve answer precision on large codebases.
  • Irreversible mistakes: Plan mode forces Claude to output a full change plan before touching files. /rewind 3 restores both conversation state and file system to three checkpoints back — not just chat history.
  • Context loss across sessions: CLAUDE.md persists rules like banned directories (/legacy), type constraints (no any), and test file conventions, eliminating repetitive prompt setup every session.

Background tasks via /tasks enable parallel workstreams — running a test suite while designing a new feature in the same terminal session.

Asia-Pacific Angle

Chinese and Southeast Asian developers building SaaS products for global markets frequently maintain bilingual codebases or multi-locale configs. CLAUDE.md is directly useful here: you can encode locale-specific rules (e.g., "never modify i18n/zh-CN files directly, always update the base en-US key first") that persist across all sessions. Teams using Cursor or continuing to evaluate Claude Code against local alternatives like Tongyi Lingma should note that the /rewind checkpoint system is more granular than most competitors — it tracks file-system state, not just conversation turns. For developers in markets with slower API response times, the background /tasks system reduces idle wait time on long refactors.

Action Item This Week

Create a CLAUDE.md file in your current project root. Add at minimum: your forbidden directories, one type or linting rule Claude keeps violating, and your test file location convention. Run one session with plan mode enabled (Shift+Tab until you see "plan") on a multi-file change and compare output quality against your previous auto-mode sessions.