I've been working on expanding HTTP Toolkit's support for this over the past year (as one part of a projectopens in a new tab funded by EU Horizon's Next Generation Internet initiativeopens in a new tab), to extend HTTP Toolkit to cover three additional rising protocols that are often used alongside simple HTTP in decentralized web applications: WebRTC, IPFS & Ethereum. If you're using HTTP Toolkit to intercept browsers, and a web application connects to another peer over WebRTC, interacts with the Ethereum blockchain, or pulls content from the IPFS network, then you'll now see this inline amongst your collected HTTP traffic, and you can create rules to rewrite these requests, define mock responses, or inject errors.