# Introduction

Welcome to the Tonomy SDK developer documentation.

Tonomy enables developers to **integrate self-sovereign identity and secure data storage** into their **Web2 and Web3 applications**. Whether you’re building a **SaaS platform requiring high-security logins** or a **Web3 dApp needing user-controlled digital signatures and credentials**, Tonomy provides a privacy-first, developer-friendly solution.

With **Tonomy ID**, users log in without passwords, sign data with private keys stored securely on their devices, and control their personal data—**without relying on third parties**.

### Why Integrate Tonomy?

* **Frictionless User Authentication**: Passwordless Single Sign-On (SSO)
* **Strong User Verification**: W3C Verifiable Credentials
* **High-Security Digital Signatures**: Non-repudiation for documents, transactions, and data
* **Data Privacy by Default**: Sovereign Data Vault for user-controlled storage
* **Flexible for Web2 & Web3**: Use in SaaS platforms, enterprise apps, dApps, and beyond

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Try it out now: [Demo App](https://demo.tonomy.io)
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Read the [Tonomy ID White Paper](https://tonomy.io/about/whitepapers)
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