Payments thatagents intercept
Protocol
first.
An SDK that intercepts HTTP 402 responses and automates on-chain payments. Every request priced, negotiated, and settled without human intervention.
HTTP 402 Middleware
Drop-in Express/Node.js middleware that intercepts 402 Payment Required responses and automates on-chain payment negotiation per request — zero manual integration.
Install.Negotiate.Ship.
Any stack,
any chain.
Native SDKs for every major backend language. The same open MPP protocol underneath — whether you're running Express middleware or a Rust binary.
TypeScript, Python, Go, and Rust — all speaking the same open Machine Payments Protocol. Plus a CLI for quick prototyping and scripting.
Real-time
payment metrics.
Connect
every stack.
MPP works alongside your existing tools. LLM providers, CI pipelines, data warehouses — your agents pay for what they use, automatically.
Automated,
not unguarded.
The SDK handles payments automatically, but you stay in control. Hard spend limits, encrypted keys, and a full on-chain audit trail for every request.
Sandboxed execution
Each payment flow runs in an isolated context with no cross-request bleed.
Encrypted keys
Wallet keys encrypted at rest and in transit. Never logged, never exposed.
Full payment audit
Every 402 intercept, negotiation, and on-chain settlement is logged and inspectable.
Spend limits
Hard per-request and per-period caps. Agents can't overspend by design.
One import.
Payments handled.
A backend SDK that intercepts HTTP 402 responses and automates on-chain payments. Works with Express, FastAPI, Go's net/http, and Rust's Axum out of the box.
TypeScript native
Full type safety for middleware config, payment responses, and receipts.
Streaming support
Handle streamed 402 responses and partial payment flows in real-time.
Multi-chain routing
Base, Solana, Ethereum, Polygon — route payments to the cheapest chain automatically.
Local dev mode
Simulate 402 flows and payment negotiation locally before going to production.
Ready to ship
machine payments?
Join developers building with the Machine Payments Protocol. Add HTTP 402 automation to your stack in minutes.
Early access — follow on X for updates
