Catalog lookup (GET /v1/assets); use it to turn tickers or names into uids. Filters: q (free text), symbol, symbols (several tickers in one call), candidate (the uid of a candidates entry; registers that coin on demand; use alone), chain+contract (an unknown Solana mint can be registered on demand; mints are case-sensitive). Size: about 0.4 KB per asset (both copies of the result). Without any filter the default limit is 50 (the whole catalog is hundreds of assets); page with limit (1..1000) and after (next_after of the previous page). An explicit limit of 0 is an error. For a q lookup with few catalog hits, candidates lists at most 5 unregistered coins (not yet priced); pass a candidate's uid as candidate to register it and make it priceable. Dynamic coins expire after 7 days without use and may get a new uid after expiry or a server reset, so do not store a dynamic uid as identity; asset.icon is a placeholder image for an asset with no image source. Edge cases: read resource ratehub://docs/behavior (behaviour notes).