Prototype · Preview: every server in the official registry, synced every 30 minutes. Reviews and accounts come in a later step.
PopNx MCPMCP servers for people who use AI · explained in plain words

WebCrypt MCP Server

by putervisionversion 1.0.1i★ –iRuns on your computer
Registry nameio.github.putervision/webcrypt

Install

Overview

Description from the maker (original English)

Zero-dependency Web Crypto & AI Agent MCP Server (AES-256-GCM, RSA-4096, PQC, Signatures).

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

  • Connection: Runs on your computer
  • Transport: stdio
  • Category: Other

Install

Pick the AI app you use, then copy the settings.

Before you install

  • Basic checks: 1 of 1 passed
  • Runs on your computer with your user’s permissions (files, network, apps).
  • The registry lists no key to fill in.

You need

  • npmNode.js installed (for the npx command)

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "webcrypt": {
      "command": "npx",
      "args": [
        "-y",
        "webcrypt"
      ]
    }
  }
}

Run this in your terminal

claude mcp add webcrypt -- npx -y webcrypt

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "webcrypt": {
      "command": "npx",
      "args": [
        "-y",
        "webcrypt"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "webcrypt": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "webcrypt"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified with the GitHub account putervision, which owns the repo

  • … Not checked yet

    Still maintained

    We have not read this repo from GitHub yet

  • … Not checked yet

    Has a licence

    We have not read this repo from GitHub yet

  • – Not applicable

    Endpoint responds

    This one runs on your computer; there is no internet endpoint

  • – Not applicable

    Sign-in with OAuth

    Runs on your computer and uses local settings instead

  • … Not checked yet

    No hidden instructions in tool descriptions

    Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Otheri

  • More stars than 0% of the other 32398 servers in this category
  • Published to the registry more recently than 29% of the other 32398 servers in this category
  • Basic checks equal to or better than 100% of the other 32398 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is WebCrypt MCP Server safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.0.1) reached the registry 3 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: Spec Driven Development, Remote Desktop Commander, AI Deprecations

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Spec Driven Development

by formulahendry

MCP Server that facilitates spec-driven development workflows, not just Vibe Coding.

Runs on your computer★ 440MITUpdated 14 months ago
Install

Remote Desktop Commander

by desktop-commander

Remote Desktop Commander: use files, terminal and processes on your own computers from any AI app.

Runs in the cloud★ 211Updated yesterday
Install

AI Deprecations

by aideprecations.com

AI model shutdown dates, replacements, change feed and webhook alerts for 8 providers.

Runs in the cloudUpdated today
Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

WebCrypt v1.0.1

Zero-dependency Web Crypto & native AI Agent Tooling (MCP) for modern JavaScript.

AES-256-GCM symmetric encryption, RSA-4096 hybrid public keys, ECDH key agreement, ECDSA/HMAC digital signatures, and Post-Quantum KEM (Kyber/Dilithium) — zero runtime dependencies, pure Web Crypto API.


⚡ Quickstart (15 Seconds)

1. Installation
# 📦 Install as project library (Node.js, TypeScript, Browser)

npm install webcrypt

🌐 Install globally (CLI utilities & global MCP tools)

npm install -g webcrypt

import { WebCrypt, WebCryptAsym } from "webcrypt";

// 🔒 Symmetric AES-256-GCM (600k PBKDF2 iterations) const wc = new WebCrypt(); const encrypted = await wc.encryptText("Secret payload", "password"); const decrypted = await wc.decryptText(encrypted, "password");

// 🔑 Asymmetric RSA-4096 Hybrid Encryption const wca = new WebCryptAsym(); const keyPair = await wca.generateKeyPair(4096); const cipher = await wca.encryptText("Secret payload", keyPair.publicKey); const plain = await wca.decryptText(cipher, keyPair.privateKey);


2. Auto-Setup for AI Agents & IDEs (MCP Server)
# Initialize MCP server, agent skills, and rules across your project

npx webcrypt init # or webcrypt init if installed globally

_Supports Google Antigravity, Cursor, Claude Desktop, VS Code / Copilot, Windsurf, Cline, and Zed._


🤖 Why AI Agents Need WebCrypt MCP

Equip autonomous coding agents with an authenticated cryptographic vault directly in their toolbelt:

  • 🔐 Confidential Local Vaulting (`encrypt_payload`): Encrypt API keys and state memory before writing to disk to prevent prompt log leaks.
  • 🛡️ Tamper-Proof Provenance (`sign_verify`): Cryptographically sign test evidence packs, release binaries, and code diffs with ECDSA or HMAC.
  • 🤝 Inter-Agent Key Exchange (`manage_keys`): Ephemeral JWK keypairs (RSA-4096, ECDH P-256/P-384) for private agent-to-agent messaging.
  • ⚛️ Post-Quantum Guardrails (`pqc_kem_sign`): Built-in Kyber KEM and Dilithium signatures future-proof long-term agent artifacts.
  • ⚡ Zero Dependencies: 100% native crypto.subtle execution across Node.js 18+, Bun, browsers, and Edge runtimes.
┌───────────────────────────────────────────────────────────┐

│ Autonomous AI Coding Agent │ │ (Antigravity / Cursor / Claude / Copilot / Cline) │ └─────────┬───────────────────┬───────────────────┬─────────┘ │ │ │ ▼ ▼ ▼ ┌───────────────────┐┌───────────────────┐┌───────────────────┐ │ state-memory-mcp ││ vision-memory-mcp ││ webcrypt │ │ (Workflow State) ││ (Visual Cache) ││ (Security Vault) │ │ • Task Graph DAG ││ • UI Grounding ││ • AES-256 Vault │ │ • Decisions & SDD││ • Layout Trees ││ • RSA/ECDH Keys │ │ • Event Ledger ││ • Visual History ││ • Digital Sigs │ └───────────────────┘└───────────────────┘└───────────────────┘


🛠️ MCP Tools Reference (6 Core Tools)

ToolAction / ModeDescription
`encrypt_payload`symmetric \asymmetric \dataEncrypt text, JSON objects, or files with AES-256-GCM or RSA-4096.
`decrypt_payload`symmetric \asymmetric \dataDecrypt ciphertext back to plaintext or structured JSON.
`manage_keys`generate \generate_random_passwordGenerate JWK keypairs (RSA, ECDH, ECDSA, RSA-PSS) or high-entropy passwords.
`crypto_hash`SHA-256 \SHA-512 \SHA-3Compute cryptographic hash digests in hex or base64.
`sign_verify`sign \verifySign and verify messages, release hashes, and evidence packs.
`pqc_kem_sign`kyber_* \dilithium_* \hybrid_*Post-quantum Kyber KEM encapsulation and Dilithium signatures.

📚 Technical Documentation Directory

Explore dedicated guides in docs/ and examples/:

GuideTopic
🚀 [Live Interactive Playground](https://putervision.github.io/webcrypt/)Test all crypto features in the browser demo.
💻 [CLI Reference Guide](docs/CLI.md)Scaffolding, global project scanning, and terminal utilities.
⚙️ [Multi-IDE MCP Setup Guide](docs/MCP_IDE_SETUP.md)Step-by-step MCP JSON configs for all major IDEs.
🔒 [Symmetric Encryption API (`WebCrypt`)](docs/API_SYMMETRIC.md)AES-256-GCM, streaming files, WebRTC E2EE, PBKDF2.
🔑 [Asymmetric Encryption API (`WebCryptAsym`)](docs/API_ASYMMETRIC.md)RSA-4096 hybrid, ECDH key agreement, ECDSA/RSA-PSS.
⚛️ [Post-Quantum Cryptography Guide](docs/PQC.md)Kyber KEM, Dilithium signatures, and Hybrid KEM.
🏗️ [Architecture & MCP Specifications](docs/ARCHITECTURE.md)Stdio JSON-RPC 2.0 protocol and chunk framing specs.
🤖 [Agent Skill Definition](.agents/skills/webcrypt-mcp/SKILL.md)Custom agent skill with automated test runner script.
📋 [Project Instructions Template](PROJECT_INSTRUCTIONS_TEMPLATE.md)Multi-agent rules template ( ).
💡 [Code Examples Directory](examples/README.md)Ready-to-run Node.js & browser recipes.

🌐 PuterVision Triad Standard

  • 📊 [`@putervision/state-memory-mcp`](https://github.com/putervision/state-memory-mcp): Persistent SQLite graph for workflow states, task DAGs, and decision trails.
  • 👁️ [`@putervision/vision-memory-mcp`](https://github.com/putervision/vision-memory-mcp): Multimodal visual layout cache, AX grounding, and video replay analysis.
  • 🔐 [`webcrypt`](https://github.com/putervision/webcrypt): Zero-dependency cryptographic vault, payload encryption, key management, and digital signatures.

🧪 Testing & Diagnostics

# Run unit & integration test matrix (30 suites, 247 tests)

npm test

Run live MCP tool test runner (25 assertions, 100% verified)

node .agents/skills/webcrypt-mcp/scripts/exercise_tools.js

Audit environment & project configuration health

webcrypt doctor


⚖️ License & Disclaimers

Developed and maintained by PuterVision. Released under the MIT License.

  • 100% Local Execution Guarantee: All cryptographic operations execute locally in memory via standard W3C Web Crypto API (crypto.subtle). Zero external API calls, telemetry, or network transmissions.
  • Trademarks & Non-Affiliation: Product names (Cursor, Claude, Google Antigravity, VS Code, GitHub Copilot, Windsurf, Cline, Zed) are property of their respective owners and used solely for compatibility identification.
Ask PopNx