I've been building AI agents for the past year, and I kept running
into the same problem: my agent couldn't sign up for anything.
It needed to create accounts, which means receiving verification
codes. It needed to send reports. It needed to check inboxes. Every
time, I'd hack something together. Resend for sending (but it can't
receive). Gmail API with its OAuth setup that takes half an hour. Or
just... doing it by hand.
So I built mails-agent. The idea is simple. Give your agent a real
email address, the same way you'd give it a tool or an API key.
npm install -g mails-agent
mails claim myagent
mails code --to myagent@mails0.com --timeout 60
That last command waits for a verification code to arrive and prints
it. Your agent can now sign up for things on its own.
I've spent years building products for people. This is the first
time I'm building something for agents, and honestly it's the most
fun I've had in a long time. It's a completely different mindset.
You're not thinking about UI or attention spans. You're thinking
about reliability, programmability, zero friction. Everything is an
API call. It just needs to work.
A couple of things I'm happy with:
1. It runs entirely on Cloudflare's free tier (Workers + D1 + R2 +
Email Routing). I wanted this to cost $0. Charging per mailbox felt
wrong for something agents need as a basic capability.
2. It works as an MCP server, so Claude Desktop and Cursor can use
it directly: npx mails-agent-mcp
MIT licensed. Self-hostable. Deploy to your own Cloudflare account
with your own domain, or claim a free @mails0.com mailbox to try it.
I'd love to hear what you'd use this for. I built it for the signup
and verify use case, but I think there are agent email patterns I
haven't thought of yet.
Demo: https://mails0.com
