Arc
The full arc from idea to shipped code.
- Claude Code: install as a plugin and run
/arc:*commands in Claude. - Codex: this repo includes
.agents/skillsso the sameskills/*/SKILL.mdworkflows can run directly in Codex (no Claude plugin install required).
What It Does
Arc provides skills covering the complete development lifecycle:
ENTRY /arc:go - Main entry point, routes to right workflow
↓
WHY /arc:vision - High-level goals (500-700 words)
↓
WHAT /arc:ideate - From idea to design doc
↓
DO /arc:implement - Plan + execute with TDD
/arc:design - UI/UX design with wireframes
/arc:build - Quick build (no formal plan)
/arc:testing - Test strategy and execution
/arc:letsgo - Production readiness checklist
/arc:legal - Generate privacy policy and terms
CROSS-CUTTING
/arc:review - Review a plan for feasibility
/arc:audit - Comprehensive codebase audit (includes hygiene)
/arc:document - Feature documentation
/arc:suggest - Opinionated next-step recommendations (+ discovery mode)
/arc:naming - Generate and validate project names
/arc:deps - Dependency management and updates
/arc:responsive - Mobile responsive audit & fix
/arc:seo - Deep SEO audit for web projects
/arc:tidy - Clean up completed plans
/arc:prune-agents - Kill orphaned subagent processes
TOOLS /arc:commit - Smart commit + push with auto-splitting
/arc:rules - Apply coding standards to project
Arc also ships a small bootstrap skill, using-arc, which acts as the control plane for
session start. It keeps startup context small and routes into the richer workflows only
when they clearly apply.
Key Principles
- Review is woven throughout, not bolted on at the end — Each design section gets micro-reviewed before moving on
- Reviewers advise, the user decides — Suggestions are presented as questions, not mandates
- One question at a time — Never overwhelm with multiple questions
- YAGNI where appropriate — Simplifications suggested, but user has final say
- TDD mandatory — Tests first, implementation second
- Frontend-design integrated — Bold aesthetic direction, not generic AI slop
Install
Claude Code (recommended)
claude plugins install arc@howells
Installs the full plugin: skills, agents, hooks, commands, references, and disciplines. This is the complete Arc experience — skills can dispatch specialized subagents, use worktrees, track tasks, and chain workflows together.
Any agent (via skills.sh)
npx skills add howells/arc
Installs skill prompts to Claude Code, Codex, Cursor, Gemini CLI, Windsurf, Cline, and 40+ agents. This only copies SKILL.md files — you get the skill instructions but not the supporting agents, hooks, or orchestration that power the full workflow.
Codex
Codex discovers skills from ~/.agents/skills (legacy ~/.codex/skills still works, and repo-local .agents/skills is also discovered).
Recommended (install once, use anywhere):
Run:
curl -fsSL https://raw.githubusercontent.com/howells/arc/main/.codex/install.sh | bash -s -- --auto-update --interval-hours 6
Install once without auto-update:
curl -fsSL https://raw.githubusercontent.com/howells/arc/main/.codex/install.sh | bash
Using In Codex
Install Once (Recommended)
Follow .codex/INSTALL.md (or run the one-line installer above), then invoke Arc skills in any project.
Repo-Local (Project Skills)
If you open this repo itself in Codex, it includes .agents/skills/* symlinks so Codex can discover the skills without a global install.
Invoking Skills
Invoke skills explicitly (recommended):
- In CLI/IDE: run
/skillsor type$to pick a skill - In the Codex app: type
$<skill-name>in chat
$start
$ideate add user authentication with magic links
Codex loads the selected skill’s SKILL.md and follows its workflow. On supported
platforms, Arc also injects using-arc at session start so skill routing is consistent
without preloading the whole system.