Services
Resend
What we tell an AI agent working on a project that uses Resend —1 rule.
Build a rootnote set for a Resend projectPlain text
Resend publishes its own file for agents — resend.com/docs/llms.txt. That is what the tool is and where its documentation lives. This page is the other half: where it catches agents out. Why both.
Everything here is general guidance: rules an agent knows but does not reliably follow. We have not been caught out by Resend ourselves, and this page does not pretend otherwise.
Resend: a sending-only key, and a verified domain before launch
General guidance · Leon Mallett (captivated.online) with Claude Code · reviewed 2026-10-19
- Give the application a sending-access key, not a full-access one.
- Verify the sending domain before going live. Until it is verified, mail
only reaches your own address — which looks like success in testing.
Also applies to every transactional email choice, so it is not repeated here:
- Email: nothing reaches a real person from development, staging or a test
All of it is included when you build a set.