Ruby HTTP client used at Lemonade as the default client for calling internal microservices and third-party services. Exposes a callback system that fires when a request completes with access to both request and response details; the Lemonade rewrite hooked into this to serialize each HTTP interaction (base URL, params, method, body → response code, body). Typhoeus also ships a built-in stubbing mechanism, which the verifier used to block all outbound traffic and replay the recorded calls as stubs.