ARCUS

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Quickstart ​

Get up and running with ARCUS in three phases: install the plugin, prepare your repository, and run your first story.

Install ​

Add the ARCUS plugin marketplace and install the plugin:

sh
/plugin marketplace add piyushbhargava1412/arcus-plugin
/plugin install arcus-plugin@arcus

These commands work the same in GitHub Copilot CLI and Claude Code. For VS Code, add the marketplace to your settings.json (chat.plugins.marketplaces) and run Chat: Install Plugin from the Command Palette. For OpenCode, use the one-command global installer — see the README for details.

1. Build Repository Context (Once Per Repo) ​

Before running stories, generate the shared context snapshot. In your agent session, ask:

generate context

Or use alternative triggers:

agentify this repo
wire me up

This invokes the repo-agentifier skill, which:

  • Analyzes repository structure → repo_scope.md and repo_map.md
  • Discovers business flows → flows/*.md files
  • Captures test patterns → testing-patterns.md
  • Captures design & coding patterns → design-and-coding-patterns.md
  • Generates AGENTS.md navigation index
  • Creates CLAUDE.md to import the context

Expected output: A populated .context/ directory with all artifacts.

Duration: 5-15 minutes depending on repository size.

When to re-run: After major codebase restructuring or tech stack changes.

2. Run the Pipeline (Per Story) ​

Point ARCUS at a user story file to start the SDLC pipeline:

arcus path/to/story.md

You can also use plan path/to/story.md to explicitly enter the default gated mode.

Default behavior: ARCUS uses the lean profile and stops after plan in gated mode. The arcus:arcus-controller runs a compact plan → build → deterministic gate → one holistic review pipeline. Use --thorough (or "profile": "thorough" in .arcus/config.json) for the full 5.x pipeline. On a cold resume, resume <STORY> continues from the checkpoint. For profiles and the three modes (gated, intelligent, afk), see Three Modes, One Pipeline.

The default lean pipeline uses these ordered stages:

  1. Scaffold → Plan — one planner writes plan.md with decisions, open questions, tasks, and inline tests
  2. Implementation — creates the branch and implements task_1..N (TDD in-thread for small plans)
  3. Code Review — gate.mjs run runs repository checks and one change-reviewer produces review.md
  4. Context Sync — runs only when gate.mjs drift detects structural drift
  5. Closure — writes the PR description in-thread and opens the pull request

Choosing Your Mode ​

ARCUS offers three modes, all driven by the same arcus:arcus-controller orchestrator:

The profile is orthogonal to the mode. lean is the default; thorough is the full pipeline, opt-in with --thorough or config.

Gated (Default) — Best for:

  • First time using ARCUS in this repository
  • Stories with ambiguities or unknowns
  • High-risk or complex changes
  • Learning how ARCUS works
  • Need to pause and resume across sessions

Runs with optional phase-boundary gates (configurable via .arcus/config.json). Trigger: arcus path/to/story.md or plan path/to/story.md.

Intelligent — Best for:

  • Cloud/CI runs (ARCUS cloud explicitly uses --intelligent)
  • Local runs that want Brainstorm questions without phase-boundary pauses
  • Want question-gating but no pipeline pausing between phases

Surfaces only Brainstorm open questions; no phase-boundary gates. Trigger: arcus path/to/story.md --intelligent.

AFK (Autonomous) — Best for:

  • High-confidence, well-defined stories
  • Familiar codebase and domain
  • Simple features or bug fixes
  • Uninterrupted 30-90 minute sessions

Never stops — open questions are recorded but never surfaced. Trigger: forge path/to/story.md, afk path/to/story.md, run afk on path/to/story.md, or arcus path/to/story.md --afk.

For a detailed comparison of all three modes, see Three Modes, One Pipeline. For a detailed breakdown of each pipeline stage, see Pipeline Concepts. To configure which model each agent dispatch uses, see Model Policy.

Quick Start Checklist ​

  • [ ] Install ARCUS plugin
  • [ ] Run generate context to build .context/ snapshot
  • [ ] Write your first story in story.md
  • [ ] Run arcus story.md to start the lean pipeline in gated mode (default)
  • [ ] Answer the open questions if ARCUS raises any
  • [ ] Verify the opened pull request

Pro Tips:

  • Your first story should use gated mode to learn the workflow
  • Keep stories focused and atomic (one feature or fix per story)
  • Answer the open questions carefully — the last chance to steer before code is written
  • You can pause anytime and resume later (both gated and intelligent modes support this)
  • Check status anytime with: "where am I?"