ARCUSYour repo writes the code. You hold the gate.

ARCUS (Any Repository Can Use Spec-driven development) turns a written requirements into a tested, reviewed pull request. You approve the big moments; it sweats the rest. For simpler ones, it lets you sleep if you like ;)

Cut-the-chase

Lets-take-it-Slow

Tell-me-Everything

How-the-Magic-Happens

What's Inside

Meet-the-Team

Spec-driven-development (SDD)

Provides orchestration of a lean Spec → Code → Pull Request flow through planning, implementation, deterministic gates, review, and closure; the full 5.x phases remain available with --thorough.

Context Engineering - the Edge !

Scans your repository to build the context snapshot (one-time) to make it "AI Ready" and also helps refresh and keep the context always in sync with the evolving code during each SDD cycle.

Three Modes (pick your pace)

One `arcus-controller` orchestrator, lean by default and thorough with `--thorough`, across three modes (gated, intelligent, afk). See [modes](/concepts/modes) for the comparison.

Multi-tool (Copilot CLI / Claude Code / VS Code / OpenCode)

One plugin format serves GitHub Copilot CLI, Claude Code, VS Code, and OpenCode from the same marketplace. Install once, use everywhere.

Install

Inside any Claude Code or Copilot CLI session:

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

For OpenCode, use the one-command global installer — see the README for details.