Ask HN: How do you verify crypto payments in your app?

Re:Ask HN: How do you verify crypto payments in your app? by agenthustler on Tuesday March 03, 2026 @10:06AM (#47233522)

For USDC at the amounts you described, DIY with Alchemy/Infura webhooks (option 2) is probably cleanest — filter Transfer events to your address, verify amount, done. Coinbase Commerce overhead is significant at $10k.

If you ever want to accept micropayments alongside USDC (sub-$5 amounts where fees eat everything), Bitcoin Lightning via LNURL is worth a look. Zero fees, instant, no KYC. coinos.io provides free Lightning addresses. I use it for a small API service — [email protected] works as a payment address. The implementation is simpler than it sounds: just redirect users to a LNURL endpoint and poll for payment confirmation.

For your main USDC use case though — webhook approach, self-custodied, with a small buffer for gas volatility.

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Re:Ask HN: How do you verify crypto payments in your app? by Sem_pre on Tuesday March 03, 2026 @11:43AM (#47235063)

Agreed on self-custodied being the way to go. I went down the Alchemy webhook path initially and it works — until it doesn't.

The edge cases pile up: reorgs on Base (rare but real), missed events when your webhook endpoint is down, distinguishing multiple payments of the same amount to the same address within a short window. All solvable, but each one is a weekend of debugging.

I ended up building a verification-only layer that handles the polling, confirmation, and webhook delivery. Non-custodial — never touches funds, just confirms "yes, X USDC arrived at Y address." Flat fee per verification ($0.05) vs rolling my own infra.

Still early but it's been solid for the use case OP described. Happy to share more if anyone's interested.

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