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Ribaunt is a stateless proof-of-work CAPTCHA library for Node.js and modern browsers. Instead of relying on a central database or third-party service to track challenge state, Ribaunt encodes everything your server needs directly into a signed JWT. Your server issues challenges, the browser solves them, and verification happens with a simple signature check — no external storage required. It’s built for developers who want reliable bot protection without the operational overhead of managing shared state.

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How it works

The flow has three steps: your server creates a signed JWT challenge, the browser widget runs a proof-of-work computation to produce a valid nonce, and your server re-verifies the signature and the nonce before accepting any action. Because the challenge payload is self-contained and signed with your RIBAUNT_SECRET, the server can verify it at any time without persisting anything between requests. For a deeper look at the cryptographic details and replay protection strategies, see the How it works page.

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Key features

Stateless

Challenges are signed JWTs — no database, cache, or shared session store needed to issue or verify them.

Browser widget

A built-in Web Component works with plain HTML. A React wrapper (ribaunt/widget-react) integrates with React and Next.js.

Replay protection

Local (process-level) replay protection is on by default. For serverless or multi-instance deployments, plug in a Redis/Valkey store.

Fully typed

Written in TypeScript with full type declarations included. No @types package needed.

Configurable difficulty

Tune difficulty, amount, and ttlSeconds per endpoint to balance security and user experience.

Themeable

Style the widget with CSS custom properties — match any design system without touching shadow DOM internals.

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Installation

Install Ribaunt from npm using your preferred package manager.
Browser solving requires a secure context — use HTTPS in production or http://localhost during development. Loading the widget from a plain LAN address such as http://192.168.x.x will fail because the Web Crypto API is unavailable in non-secure contexts.

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Use the docs with AI tools

Ribaunt does not ship a Model Context Protocol (MCP) server in the ribaunt npm package. You can still give AI assistants direct access to this documentation:
  • Docs MCP server: this documentation site hosts an MCP server at its /mcp endpoint. Add that URL to any MCP-compatible client, such as Claude Code or Cursor, to search these docs from your assistant.
  • Context7: Ribaunt is indexed on Context7. Assistants configured with the Context7 MCP server can pull current Ribaunt documentation and code examples from there.
  • Plain-text export: the full documentation is available at the site’s /llms.txt and /llms-full.txt endpoints for tools that ingest raw Markdown.

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Next steps

Quickstart

Set up your secret, create server endpoints, and add the widget to your page in under five minutes.

How it works

Understand the full proof-of-work flow, JWT challenge structure, and replay prevention in depth.