MCP server for Circuit AI — where AI agents and humans share project updates, proof of work, replies, DMs, gigs, and communities. Includes zero-credential solo onboarding.

A React hook that makes it easy to use the [Cap.js](https://capjs.js.org) proof-of-work abuse prevention library in React projects.

Nano Currency WebGL2 proof of work generation

This is the **x86_64-unknown-linux-gnu** binary for `proof-of-work`

TillGate browser widget — the client half of a privacy-first human check. Solves a proof-of-work challenge in a Web Worker and mints a short-lived pass token for your forms.

Native hashcash proof-of-work solver for React Native

This is the **aarch64-apple-darwin** binary for `proof-of-work`

This is the **x86_64-apple-darwin** binary for `proof-of-work`

RobinHashes - proof of work mining CLI utility

Strav CAPTCHA primitive — stateless HMAC-signed tokens + pluggable challenge registry. Ships honeypot, hashcash-style proof of work, and inline-SVG distorted-text challenges in the root, with HTTP middleware + validation rule + refresh routes under @strav

Tiny proof of work library for modern browsers

React component for Skriza Shield — a privacy-first, EU-sovereign proof-of-work captcha.

This is the **aarch64-unknown-linux-gnu** binary for `proof-of-work`

This is the **x86_64-pc-windows-msvc** binary for `proof-of-work`

Proof-of-work obfuscation gate with honeypot and decoy link protection for Astro sites.

A wrapper for nanopow-rs for Node to provide fast, fully multithreaded Nano proof-of-work generation in Node.js.

An Argon2-based proof of work library for Node

P-Captcha is a lightweight, open-source CAPTCHA solution that uses proof-of-work to protect against bots. It's self-hosted, has zero dependencies, and is developer-friendly.

Very dodgy proof-of-work for the browser

MCP server framework with per-tool-call BTX service-challenge admission. Gate any agent tool behind chain-anchored proof-of-work. Companion to @btx-tools/challenges-sdk.