★ 11k
May 2026
MIT
AI agents
What we checked ourselves
Not copied from the project's own blurb. These are things we opened and verified, with the date.
- 23 Aug 2026We checked that the link to the project still resolves.
- 14 Aug 2026We read the licence text itself (LICENSE). No unusual restrictions were stated.
- 31 Jul 2026We read the project's own documentation and found no sign that development has stopped.
Where this sits among the 114 tools we list in AI agents
- Commercial use confirmed as allowed95 of 114
- Requires terminal commands21 that do not →
- Requires an API key29 that do not →
- Sends your input to the provider11 that do not →
Counted from our own checks: every tool we list is examined against the same criteria.
What it does
An email client you can run yourself, or point at Gmail and other providers, with agents layered on for triage and drafting. The pitch is ownership: no tracking, no data collection, and the whole thing readable. Two honest qualifications — connecting an external provider puts that mailbox under their policies regardless, and the AI features send message content to whichever model you configure. Setup involves Node, Docker and Google Cloud credentials, so it is a project rather than an install. MIT.
Summary based on the project's own description. The Japanese page has a fuller beginner guide: setup difficulty, what to prepare, and a step-by-step start.
Screenshots & visuals
Before you start
- Setup difficultySome setup needed
- Command lineRequired
- API keyRequired
- Sends data onlineYes
Judged automatically from the project's own metadata. Always confirm on the official page.
Zero FAQ
- Is Zero free?
- Zero itself is free, but it needs an API key for an external AI service. That service charges separately, though some have a free tier.
- Do I need to install anything or write code to use Zero?
- It needs the command line. If you are not comfortable typing commands, expect to get stuck during setup.
- Does Zero work on a phone?
- No. It needs a computer.
- Can I use Zero commercially?
- The licence is MIT, which permits commercial use. Conditions such as keeping the copyright notice still apply, so read the licence text before shipping it inside something.
How it compares
The conditions that decide whether you can actually use it, side by side.
| Tool | Command line | API key | Sends data out | Phone | Commercial use |
|---|---|---|---|---|---|
| Zero (this page) | Required | Required | Yes | No | Yes |
| atomic-mail-agentic | Required | Required | Yes | No | Yes |
| macro | Not needed | Not needed | Yes | No | Yes |
| openclaw | Required | Required | Yes | No | Not verified |
"Sends data out" means your input is uploaded to someone's server. Pick "No" when the material cannot leave your organisation.