The technology disclosed includes a system to apply data loss prevention (DLP) to cloud-based services for which no service-specific parser is available. The system determines that a known cloud-based service is being accessed via an application programming interface (API) and no service-specific parser is available for the API being accessed. The system applies a category-directed parser to the API being accessed. The category-directed parser includes multiple category-directed match rules derived from multiple syntaxes used by numerous known providers to implement a category of service. The category-directed parser collects metadata from content being conveyed via the API and assigns the collected metadata to variables. The system invokes a DLP processor and sends the collected metadata to the DLP processor for use in focusing analysis of content being conveyed via the API.