As part of the API rate-limiting, the npm registry search API returns no results for any search query that is fewer than four characters. (Note: the npm blog entry about rate-limiting incorrectly specifies this limit as three characters.)
This is disingenuous because there ARE packages with names that are shorter than four characters and those packages currently cannot be searched by name.
I propose that the search API be changed so that queries with fewer than four characters return precisely one exact match, if a package of that name exists. This keeps the server load low but simultaneously makes the search API much better. After all, a search for “aa” shouldn’t return zero results when there IS a package named “aa”. Since you allow package names shorter than four characters, the search API should be capable of finding them.