WebCrypt MCP Server

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.

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⚡ 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);

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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.

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🤖 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   │
└───────────────────┘└───────────────────┘└───────────────────┘

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🛠️ MCP Tools Reference (6 Core Tools)

Tool	Action / Mode	Description
encrypt_payload	symmetric | asymmetric | data	Encrypt text, JSON objects, or files with AES-256-GCM or RSA-4096.
decrypt_payload	symmetric | asymmetric | data	Decrypt ciphertext back to plaintext or structured JSON.
manage_keys	generate | generate_random_password	Generate JWK keypairs (RSA, ECDH, ECDSA, RSA-PSS) or high-entropy passwords.
crypto_hash	SHA-256 | SHA-512 | SHA-3	Compute cryptographic hash digests in hex or base64.
sign_verify	sign | verify	Sign and verify messages, release hashes, and evidence packs.
pqc_kem_sign	kyber_* | dilithium_* | hybrid_*	Post-quantum Kyber KEM encapsulation and Dilithium signatures.

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📚 Technical Documentation Directory

Explore dedicated guides in docs/ and examples/:

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

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🌐 PuterVision Triad Standard

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

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🧪 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

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⚖️ 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.