In order to improve performance for HTTP API clients, httpcache provides simple tools for caching and invalidating cache. It includes the HTTP verb functions GET, PUT, PATCH, POST, and DELETE, which are drop-in replacements for those in the httr package. These functions are cache-aware and provide default settings for cache invalidation suitable for RESTful APIs; the package also enables custom cache-management strategies. Finally, httpcache includes a basic logging framework to facilitate the measurement of HTTP request time and cache performance.