How Blueprint SDK Turns x402 Payments into Runnable Jobs

HTTP Status 402 Finally Has a Job HTTP status code 402 has been "reserved for future use" since 1999. For twenty-seven years it sat in the spec, a placeholder for a payments web that never materialized. In 2025, Coinbase and Cloudflare's x402 protocol gave it real work: a client hits an endpoint, receives a 402 response with pricing information, signs a stablecoin payment, and resends the request with proof of settlement attached as an HTTP header. No API keys, no billing dashboard, no monthly invoices. Just cryptographic proof that money moved before compute burned. Blueprint SDK integrates the x402 payment protocol through its blueprint_x402 crate, which runs an axum HTTP server that verifies x402 payment headers via an external facilitator, settles payments on-chain before execution, and converts each verified payment into a standard JobCall. If you're new to the blueprint model, How Blueprints Work covers the architecture. Job handlers work identically whether triggered by x402 pay