Explicit trust
Versioned composite identities, safety-number comparison, rotation controls, and fail-closed trust mutation.
JavaScript-first encrypted messaging
Private communication, composed your way.
A portable TypeScript SDK for encrypted messaging, devices, groups, attachments, and explicit storage and transport composition.
Browser nativeWeb Crypto and portable storage
Node and ExpoRuntime-specific adapters
AGPL or commercialChoose the rights your product needs
Protocol building blocks
Cryptographic state belongs to your product.
Compose a Signal-inspired protocol profile without outsourcing private keys, plaintext, or application ownership.
Modern session state
PQXDH, Double Ratchet, post-quantum ratcheting, multi-device session management, and bounded state recovery.
Portable boundaries
Choose local storage, delivery, and encrypted-object adapters for browser, server, and native JavaScript environments.
Portable by construction
Private keys stay with your application.
Your runtime owns identity and session state. Explicit adapters connect the encrypted output to infrastructure you choose.
01Your applicationBrowser · Node · Expoprivate state
02Protocol SDKKeys · sessions · groupsciphertext out
03Your adaptersStorage · delivery · objectsexplicit boundary
The SDK defines the cryptographic and adapter contracts. It does not require a hosted Signal Protocol service.
import { createSignalClient } from '@signal-protocol/sdk';
import { indexedDbStore } from '@signal-protocol/sdk/local/store/web';
const storage = await indexedDbStore();
const client = await createSignalClient({
identity: { userId: 'alice' },
adapters: { storage },
});
await client.send('bob', 'hello');One explicit composition root
Start locally. Add only the adapters you need.
The SDK surface stays stable while applications select runtime storage, transport, and object persistence independently.
Licensing
Open source or commercial production rights.
Use the complete SDK under AGPL, or purchase commercial rights for a proprietary product.
Community
AGPL
Free
For projects that can satisfy the AGPLv3 obligations.
- Complete SDK
- Self-operated infrastructure
- Community support
Startup
One product
$5k/ year
Commercial production rights for one named product and legal entity.
- Browser, Node, and Expo
- SDK updates
- Email support
- Self-service checkout
Growth
Integration support
$20k/ year
Commercial rights with prioritized updates and implementation support.
- One named product
- Priority updates
- Integration support
- Additional products available
Enterprise / OEM
Portfolio rights
$50k+/ year
Negotiated portfolio, redistribution, security, and support terms.
- Product or portfolio scope
- Onboarding and SLA
- Security review
- Redistribution terms
Prices shown are the proposed annual list prices for the named scope. The signed commercial agreement controls product scope, renewal, support, and usage rights.
Begin with the protocol