I'm creating a search site for technical / lab items, some of the important specs have special characters like '+'. Regular ebay search and the search API cannot seem to handle these. Is there an API that allows me to download all listing for a category (i.e. lab equipment)? Then I can process the titles and items descriptions myself and search with special characters.
Have you tried URL-encoding the special characters? I don't know if that works; never tried it. There is no API that will allow you to bulk-download a category. The best you can do is findItemsByCategory, which will grab a max of 100 items at a time from the category you specify; you can specify which page of results you want. You could also use various filters to restrict this further. And using multicURL (PHP), you could make up to 18 simultaneous calls, so 1800 items at once (be aware, it's eBay that restricts you to 18 simultaneous calls). Depending on the category, of few of these chained together could get you what you want. Foul