WebCrypt MCP Server
io.github.putervision/webcrypt · 15 stars · JavaScript · MIT
MCP server Zero-dependency Web Crypto & AI Agent MCP Server (AES-256-GCM, RSA-4096, PQC, Signatures).
Install
The repo has no one-line install. Follow its README.
Published as
- npm
webcryptstdio
From the server's entry in the official MCP Registry.
Files
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.subtleexecution 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)
| 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. |
📚 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. |
🌐 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.
🧪 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.
Facts
- Kind
- MCP server
- Group
- Uncategorized
- Stars
- 15
- License
- MIT
- Language
- JavaScript
- Last push
- 2026-08-21
- Forks
- 2
- MCP Registry
- io.github.putervision/webcrypt
- Homepage
- putervision.github.io/WebCrypt
- Topics
- cryptography, e2ee, e2ee-encryption, encryption, hmac, jwe, agent-security, agent-security-tools, mcp, mcp-client, mcp-server, mcp-tools, model-context-protocol
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