A data collector may monitor a data source and identify updated data, which may be processed and prepared for inclusion into a search database. The data collector may have various handlers that may interact with a data source, which may be a database, web service, file system, collaboration system, or other source, and may store a identifying signature and content signature for each document or item. The signatures may be used to identify new, changed, or deleted items, and a payload may be created containing the updates.