Saguaro is a background daemon that reviews AI-generated code and feeds findings back to the same agent that wrote it. The agent evaluates the critique, it knows why it made those decisions in the first place, and self-corrects what's actually wrong.

The flow: you tell Claude Code to build something. Claude writes code. Saguaro's stop hook triggers a background review (the user sees nothing). On the next turn, findings come back to Claude. Claude says "I see some issues with my approach, fixing now" and corrects itself. No human typed anything. No blocking.

It uses your existing Claude Code / Codex / Gemini subscription. No API key needed. No external account. Everything runs locally. The daemon self-spawns on demand and auto-shuts down after 30 minutes of inactivity.

There's also a rules engine for teams that want more deterministic enforcement. You write rules as markdown files with YAML frontmatter, scoped to specific file globs. But the daemon works out of the box with zero rules. It reviews like a senior staff engineer: bugs, security, regressions, dead code. The rules engine adds more precision for teams/individuals that need it.

Setup is "sag init" + restart CC + go back to coding. That's it.

Apache-2.0. TypeScript.