Research preview since v2.1.111 (April 20). Run `/ultrareview` and a fleet of reviewer agents fans out across your branch diff in a cloud sandbox, independently verifying each bug before surfacing it — no false positives from style suggestions. Pro and Max subscribers get 3 free runs through May 5, then $5–20 per review billed as extra usage. `claude ultrareview <PR#>` runs headlessly from CI. Requires claude.ai authentication; not available on Bedrock, Vertex AI, or Foundry.
anthropic
/ultrareview (or: claude ultrareview <PR-number> from CI)
Shipped in v2.1.118 (Week 17, April 20–24). Open `/theme` to pick from built-in presets or create a named theme, then hand-edit JSON files in `~/.claude/themes/` to override only the tokens you care about. The big unlock: plugins can now ship their own themes — a design skill can carry its own terminal aesthetic alongside its instructions, making the whole Claude Code environment cohesive.
Anthropic's engineering team confirmed three simultaneous bugs caused the March–April quality regression: (1) A March 26 caching change accidentally cleared Claude's thinking history every turn for the rest of a session instead of just once after an hour of idle — Simon Willison flagged this as personally painful since he often leaves sessions for a day before returning. (2) Default reasoning effort was silently downgraded from `high` to `medium` on March 4 to reduce latency (reverted April 7). (3) A verbosity-reduction prompt added April 16 degraded coding quality and was reverted April 20. All three are fixed; default effort for Pro and Max is now `high`.
841-star companion repo to arXiv paper 2604.14228 (April 2026) — the first systematic source-level analysis of Claude Code's full TypeScript source. The headline finding: only 1.6% of the codebase is AI decision logic; the remaining 98.4% is deterministic infrastructure. The paper maps five human values through 13 design principles to specific implementation choices, and includes a 'Build Your Own Agent' guide. YouTube video posted 1 week ago. Produced by VILA Lab / Zhiqiang Shen et al.
161 GitHub stars, 220 Product Hunt upvotes (#6 on April 15). A 100% Swift macOS desktop widget that shows exactly what Claude Code is doing at all times — eight named states (outline/working, orange/attention, purple/YOLO, red/recording, green/speaking, dimmed/hidden) and four auto-approval presets from Strict to YOLO. Standout feature: on-device voice I/O via WhisperKit + Kokoro TTS with a global ⌥R hotkey or double-clap to go fully hands-free. No accounts, no telemetry, no API keys — hooks directly into `~/.claude/settings.json`. macOS 14+.
399 stars since launching April 17 alongside Claude Design. Curates DESIGN.md files organized by 9 aesthetic families — Editorial Minimalism, Terminal-Core, Warm Editorial, Data-Dense Pro, Cinematic Dark, Playful Color, Glass/Soft-Futurism, Neon Brutalist, and Indie picks — plus remix recipes, community feedback, and patterns for detecting AI-slop tells. Acts as the Claude Design equivalent of what awesome-claude-code is to the agent ecosystem: a structured entry point for practitioners.
Week 17 (April 20–24). When you switch focus away from a Claude Code terminal and come back, you now get a one-line recap of what happened while you were gone — essential for users juggling multiple sessions at once. Run `/recap` on demand at any time; configure or disable the automatic version from `/config`. Force it with `CLAUDE_CODE_ENABLE_AWAY_SUMMARY=1` when telemetry is off.
19.2k stars — 1,100+ agent skills curated from official engineering teams at Anthropic, Google, Vercel, Stripe, Cloudflare, Netlify, Microsoft, Hugging Face, Figma, and more. The pitch: 'hand-picked, not AI-slop generated.' Compatible with Claude Code, Codex, Gemini CLI, Cursor, and GitHub Copilot. Browse the full catalog at officialskills.sh. Positioned as the authoritative source for production-grade skills backed by the companies that built the APIs.
Today's release (April 28) ships several quality-of-life changes: `alwaysLoad: true` in MCP server config skips tool deferral so your most-used server tools are always present without an extra round-trip; `claude plugin prune` cleans up orphaned auto-installed plugin deps; a type-to-filter search box in `/skills` saves hunting through long lists; `PostToolUse` hooks can now replace tool output for any tool (enables post-processing of Bash results inline); MCP servers auto-retry up to 3× on transient startup errors; iTerm2 clipboard access via `/terminal-setup`; worktree switching; and a `/proactive` alias.
2k stars — open-source Claude Code marketplace with 423 plugins, 2,849 skills, and 177 agents, browsable at tonsofskills.com. The `ccpi` CLI package manager (`pnpm add -g @intentsolutionsio/ccpi`) makes install as fast as `ccpi install devops-automation-pack`. Covers 18+ categories including SaaS packs for ClickUp, Algolia, Fly.io, and Intercom. All MIT-licensed, updated daily by GitHub Actions.
"Why use many token when few token do trick" — 47.8k+ stars. Cuts ~65–75% output tokens and ~46% input tokens while preserving technical accuracy. One-line install for Claude Code, Cursor, Windsurf, Copilot, Gemini CLI, and 40+ others. Still the first recommendation in every r/ClaudeAI budget thread.
costskill
plugin · token · marketplace · terminal
claude plugin marketplace add JuliusBrussee/caveman && claude plugin install caveman@caveman
36.3k stars — turns any folder of code, docs, papers, images, or videos into a queryable knowledge graph wired into Claude Code via a PreToolUse hook. v0.5.0 benchmarks: 70x fewer tokens per search vs brute-force reads. Covered by @charlieautomates as core to their 'replaces OpenClaw' stack.
cost
memory · token · viral
uv tool install graphifyy && graphify install
↑ Day 2 — 36.3k stars; strongest knowledge-graph option for context-narrowing
13.4k stars — builds a persistent AST knowledge graph with Tree-sitter + SQLite, traces blast-radius on every changed file, and gives Claude exactly the context it needs. Benchmarks: 6.8× fewer tokens on code reviews, 49× on routine daily tasks. v2.3.2. Auto-detects Claude Code, Codex, Cursor, and Windsurf on install.
185k+ stars — clean-room Rust rewrite of the Claude Code agent harness, initiated after the April 1 source map leak exposed 512K lines of TypeScript. Sigrid Jin leads the project. 109k forks, active Discord.
viral
harness · security
git clone https://github.com/ultraworkers/claw-code && cd claw-code/rust && cargo build --workspace
↑ Day 6 — 185k+ stars; Rust rewrite advancing with new contributors joining this week