Freshness and caching

Every response has a meta object that says how current the answer is.

• observed_at: when the DNS answer was fetched.
• fresh_until: until when the answer can be used without checking again.
• cache_hit: whether the answer came from the cache.
• resolver: the public resolver that answered, when a resolver was used.

TTL rules

DNS answers are cached for at most 5 minutes, and never longer than the TTL of the record. fresh_until is the earliest point at which any answer used in the result expires.

Why two calls can differ

You may get different answers if you call twice. The record may have changed between the calls, one answer may come from the cache, and public resolvers can be at different stages of a change. Use observed_at to tell which answer is newer.