A system and method for per-client, per-type customizations to posts in an activity stream comprises an extraction pipeline and a rendering pipeline. The extraction pipeline can include a library of embedded code, data type taxonomy and an embed converter. The data type taxonomy is coupled to an activity source to receive activity information, and to produce a first protocol buffer. The embed converter produces a type-specific protocol buffer from the first protocol buffer and embedded code based in part upon the type of activity and the type of client. The type-specific protocol buffer is provided to the client to process activity information or present activity information. The disclosure also includes a method for processing a post in an activity stream on a per-client, per-type basis.