llms.txt@packages/web/public git:20260824.d85f0e7A

Immutable. This exact content never changes and is served at /api/v1/blob/a3be408af7399114.

# reins

> reins is a command-line tool that lets coding agents drive the user's real, logged-in Chromium browser. It has three local pieces: a CLI, a daemon the CLI starts on demand, and a Manifest V3 browser extension. Everything binds 127.0.0.1. There is no cloud half and no telemetry. Open source, MIT licensed, and still 0.x, so commands can change between releases.

Key facts:

- Install: `npm i -g @karnstack/reins`, then add the reins extension from the Chrome Web Store in any Chromium browser (Chrome, Brave, Edge, Arc, Dia).
- Teach an agent: `npx skills add karnstack/reins`. Agents without skill support can read `reins help`.
- Core loop, in three beats. Look: `reins snapshot` lists interactive elements with refs. Act: `reins click --ref e7` or `reins type --ref e3 --text "…"`. Check: `reins text` or `reins screenshot`.
- Site permissions: every site resolves to a tier, one of deny, read, or full. The extension enforces it. Grants happen only through a click in the extension popup, and the CLI can tighten the policy but never loosen it.
- Security: the daemon binds 127.0.0.1 and validates the Host header. Only allowlisted chrome-extension:// origins may connect. Chrome shows its native debugging banner the whole time the extension is attached.
- Limits: Chromium only, so no Firefox and no WebKit. No headless mode. Not built for CI. With two browsers connected, the commands that act on a page or a tab need `--browser <id>`, because reins never guesses which one you meant.

## Docs

- [Getting started](https://reins.tech/docs): install the CLI and extension, teach your agent, check the loop
- [Commands](https://reins.tech/docs/commands): the full command reference, covering tabs, snapshot, click, type, fill, screenshot, console, network, eval, and cdp
- [Site permissions](https://reins.tech/docs/permissions): the deny, read, and full tiers, and how grants work
- [Architecture](https://reins.tech/docs/architecture): how the CLI, daemon, and extension fit together
- [Security](https://reins.tech/docs/security): the localhost-only security model
- [Install without the store](https://reins.tech/docs/sideload): stage the bundled extension for Chrome's Load unpacked
- [How it compares](https://reins.tech/docs/comparison): reins next to agent-browser, dev3000, and playwright-mcp
- [FAQ](https://reins.tech/docs/faq): common questions

## Optional

- [Changelog](https://reins.tech/changelog): release notes for the CLI and extension
- [Privacy policy](https://reins.tech/privacy): nothing reins handles leaves your machine
- [GitHub repository](https://github.com/karnstack/reins): source for the CLI, daemon, extension, and this site
- [npm package](https://www.npmjs.com/package/@karnstack/reins)