repourl canonicalizes repository, forge-page, release-archive and registry URLs into stable keys (github.com/curl/curl), with hints from well-known download areas and project sites to the repositories they come from. fetch is the one HTTP client every lookup goes through: an on-disk cache, per-host pacing (crates.io and the OBS API at one request a second), retries, published rate-limit windows (short ones are waited out, long ones fail fast), forge tokens, an operator contact in the User-Agent, and the proof-of-work check openSUSE puts in front of its services.