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
npm install webcrypt
npm install -g webcrypt
import { WebCrypt, WebCryptAsym } from "webcrypt";
const wc = new WebCrypt();
const encrypted = await wc.encryptText("Secret payload", "password");
const decrypted = await wc.decryptText(encrypted, "password");
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)
npx webcrypt init
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)
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/:
🌐 PuterVision Triad Standard
🧪 Testing & Diagnostics
npm test
node .agents/skills/webcrypt-mcp/scripts/exercise_tools.js
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.