Every agent gets an Ed25519 identity. Every message is signed and verified. Framework-agnostic. One line to install.
$ npm install @meshsig/sdk
Agents execute instructions from untrusted sources — GitHub issues, emails, web pages. No way to verify if an instruction is legitimate or malicious.
Any script can pretend to be any agent. No cryptographic proof of who sent a message.
When something goes wrong, no tamper-proof record of what happened, who did it, or when.
Agents declare their own capabilities. No reputation system based on verified interactions.
The core cryptographic library. Ed25519 identity, signing, verification, handshake. Zero runtime dependencies beyond the crypto primitives.
npm install @meshsig/sdk
import { generateIdentity, sign, verifyWithDid } from '@meshsig/sdk';
// Every agent gets a cryptographic identity
const agent = await generateIdentity();
console.log(agent.did); // did:msig:3icqQkmJWby4S5rpaSRoCcKvjKWdTvqViy...
// Sign instructions from trusted sources only
const signature = await sign('deploy to production', agent.privateKey);
// Before executing ANY instruction — verify origin
const trusted = await verifyWithDid('deploy to production', signature, agent.did);
if (!trusted) throw new Error('Instruction origin not verified — blocked');
// The Cline attack would have been stopped here.
// GitHub issue titles have no valid did:msig: signature.
Ed25519 keypair + W3C DID per agent
Mutual challenge-response verification
Every message carries a digital signature
Reputation earned through real interactions
Same algorithm behind SSH, Signal, WireGuard, TLS 1.3. Deterministic, side-channel resistant, 32-byte keys.
Every agent gets a decentralized identifier: did:msig:... — universally verifiable, impossible to forge.
Every signed message logged with cryptographic hashes. Export compliance reports via API or CLI.
Connect MeshSig instances across servers. Agents on different machines discover and verify each other.
Rotate an agent's keypair without losing its DID. Old key invalidated immediately. Full rotation history.
Permanently revoke compromised agents. Public revocation list. All messages blocked with 403.
Built-in DDoS protection. 60 requests per minute per IP. Configurable thresholds.
Anyone can verify a signature in the browser or via API. No account needed.
# Install and generate identity
npx meshsig init
✓ Identity generated
DID: did:msig:3icqQkmJWby4S5rpaSRoCcKvjKWdTvqViyPrCEC7Tek2
# Sign a message
npx meshsig sign "Deploy the new model to production"
✓ Message signed
SIGNATURE: HkyrXOPOXF7v422A4iOcg/qkg...
# Verify
npx meshsig verify "message" "sig" "did:msig:..."
✓ SIGNATURE VALID
# More commands: identity, agents, stats, audit, rotate-key, revoke, revoked, start
# MCP Server — connect to any AI tool
npx meshsig-mcp # 9 tools for Claude, Cursor, Windsurf, Cline
# Start the dashboard
npx meshsig start --port 4888
● DASHBOARD http://localhost:4888
Instructions without valid did:msig: signature are blocked before execution
Ed25519 — SSH, Signal, WireGuard, TLS 1.3
W3C DID standard (did:msig:)
Mutual challenge-response with nonce
Local SQLite — no cloud dependency
Tamper-evident log, JSON export
New keypair, same DID, old key dead
Public revocation list, 403 on revoked
60 req/min per IP, DDoS protection
Open source. MIT license. No cloud. No API keys. One line to install.