On the bundled sample: 8 findings (8 errors, 0 warnings) in 1 file from 18 rules.

Who it’s for
For Node and Python teams moving transactional email from Twilio SendGrid to Resend.

What breaks, and when
sandboxMode has no Resend field, so the email is really sent. SendGrid event ‘bounce’ never arrives from Resend, so the bounce handler stops firing.

What you get
• SKILL.md, an offline Node scanner and the 18-rule table
• file:line, severity and the Resend call to write

See it first
The real output of the bundled example is on getreadystack.com/skills/sendgrid-to-resend-migration/ — free, no sign-up, so you see what it finds before you pay.

Install in 30 seconds
Unzip into ~/.claude/skills/ (all projects) or your-repo/.claude/skills/ (one repo), then ask Claude Code: “We’re switching our transactional email from SendGrid to Resend next sprint. What in this repo has to change? Don’t edit anything yet.”. Needs Node 16+.

What it does not do
It calls neither SendGrid nor Resend and needs no API key. No network calls, no edits without your OK.

FAQ
Q: How is this different from asking Claude without the skill?
A: The skill carries a dated rule table and a scanner that reads every file, so Claude quotes the exact date and line instead of guessing from memory.
Q: How do I get the files?
A: After paying, open it in your Whop library: in “Download — sendgrid-to-resend-migration” the lesson “sendgrid-to-resend-migration.zip” has the zip attached.