The TypeScript MPP SDK ( mpp-test-sdk on npm) lets you build and test pay-per-request APIs on Solana in minutes. One function on the server. One function on the client. No Stripe, no database, no wallet pop-ups. The problem with API monetisation today Every paid API you've ever built follows the same playbook: create a Stripe account, issue API keys, build a usage-tracking database, write billing logic, handle failed payments, deal with dunning emails. You spend more time on billing infrastructure than on the API itself. HTTP 402 was supposed to fix this. It's been reserved in the HTTP spec since 1999, sitting there with the description "Payment Required", waiting for someone to actually use it. The missing piece was always a payment layer — something fast enough to pay per request without a 3-second checkout flow. Solana makes it possible. Sub-second finality, near-zero fees, and a simple transfer instruction. MPP wires it all together.…