Last week I wrote about the French voiceover API that only accepts payment from robots. Today: the part people actually asked me about — how do you verify a $0.05 payment on-chain with zero payment processor, zero SDK, and zero KYC?
The answer: one Python function, ~40 lines, stdlib only. Here's the real production code.
The setup
My endpoint sells French neural TTS voiceovers for $0.03–0.05 USDC. At that price, Stripe is a non-starter (their floor is ~$0.50 per charge) and any processor's KYC kills the "robots welcome" model. So payments go through the x402 pattern: client pays USDC on Base, sends me the transaction hash, I verify it myself against a public RPC before delivering.
The verification function
