Core concepts

The library is small and layered. One contract, three transports, and a handful of capabilities composed on top.

• Architecture — the contract, the facade, and how the layers compose.
• Resolvers — the socket, DoH, and authoritative transports.
• Domain verification — authoritative TXT ownership checks.
• Propagation — authoritative-vs-recursive comparison and its honest scope.
• Chain resolution — follow CNAME chains and expand SPF include/redirect trees to a complete endpoint list; loop-safe and bounded.
• Delegation tracing — walk a name's delegation from the root down, and the reverse chain for an IP; loop-safe like dig +trace.
• Performance & when to use — every lookup is uncached (and slower); use it for freshness/transparency, not as a hot-path resolver.