Zero (0.email)
An open-source AI email app you can self-host, with Gmail and Outlook connections, a unified inbox, and an MIT license.
Zero is an open-source, self-hosted AI email app for people who want control over their inbox software while keeping accounts with providers such as Gmail and Outlook.
Zero brings connected email accounts into a unified inbox and uses AI agents and LLMs for email assistance. You can customize its interface and features, and its emphasis on extensibility makes it relevant to developers who want to adapt an email app or add integrations. The MIT license permits modification and reuse.
Self-hosting applies to the email app; connected providers still handle data under their own privacy policies. Zero states that it doesn't track, collect, or sell user data, but that doesn't extend to those external services. Its email sync storage uses Durable Objects and an R2 bucket, so running the app yourself shouldn't be read as a promise that all email data stays on your machine.
The app uses a TypeScript and React frontend with a Node.js backend and PostgreSQL. Gmail connections use Google OAuth. Deployment requires provider OAuth setup, configured services and model-service credentials for the AI workflows.
