Past session · Wed, Oct 7
A customer pays once. Your app charges them twice. Nobody told you this could happen.
Myles on the moment real money starts moving through something you built and what happens when a payment gets sent twice by accident, and what you say to someone staring at a spinner, not knowing if their money is gone.
Recording availableAired Wed 7 Oct · 8:00 PM EAT
500+ developers already learning together every week
What the hour looks like
No slides read aloud. A feature, built.
The session in three movements — watch it happen live, then do it yourself with the template.
app/api/ai/route.ts
// live: shipping an AI feature
const ai = new Anthropic();
export async function POST(req) {
const { prompt } = await req.json();
const stream = await ai.messages.stream({
model: "claude-sonnet-4-6",
messages: [{ role: "user", content: prompt }],
});
return stream.toResponse();
}
Forty minutes of live coding — a real feature on a real Next.js app.
COST / 1K REQUESTS
GPT-4 CLASSKES 1,940
CLAUDE SONNETKES 1,290
OPEN-SOURCE (HOSTED)KES 610
ILLUSTRATIVE — WE PULL THE REAL NUMBERS LIVE
The per-request costs nobody puts in the tutorial.
PRE-FLIGHT
Streaming responses working
Fallback when the API is slow
Spend alerts before the surprise
Template pushed to registrants
DEPLOYED · LIVEYou leave with the template — and your questions answered.