- SoupSessionFeature — Interface for miscellaneous session features
- SoupAuthManager — HTTP client-side authentication handler
- SoupContentDecoder — Content-Encoding handler
- SoupContentSniffer — Content sniffing for SoupSession
- SoupCookieJar — Automatic cookie handling for SoupSession
- SoupCookieJarText — Text-file-based ("cookies.txt") Cookie Jar
- SoupCookieJarDB — Database-based Cookie Jar
- SoupHSTSEnforcer — Automatic HTTP Strict Transport Security enforcing for SoupSession
- SoupHSTSEnforcerDB — Persistent HTTP Strict Transport Security enforcer
- SoupLogger — Debug logging support
- SoupProxyResolverDefault — System proxy configuration integration