Middleware Domain

Express.js middleware and client utilities for adding cryptographic authentication and micropayment gating to HTTP services. There are two distinct payment paths: @bsv/payment-express-middleware layers payment requirements on top of authenticated Express routes, while @bsv/402-pay is an independent HTTP 402 flow that can work without auth middleware.

Packages

Package	Purpose
@bsv/auth-express-middleware	Express middleware implementing BRC-103 peer-to-peer mutual authentication via BRC-104 HTTP transport. Verify request signatures, attach verified identity to req.auth, and optionally exchange verifiable certificates.
@bsv/payment-express-middleware	Express middleware for HTTP 402 Payment Required micropayment gating. Requires @bsv/auth-express-middleware first, then derives payment requirements from the authenticated identity context.
@bsv/402-pay	Independent client-side and server-side HTTP 402 payment handler. Auto-pay 402 responses on the client; validate and accept payments on the server with caching and replay protection, without requiring auth middleware.