At the core of synopsis is a representation of the source code to be analyzed called an Abstract Semantic Graph (ASG). Language-specific syntax gets translated into an abstract graph of statements, annotated with all the necessary metadata to recover the important details during further processing.

At this time only one particular type of statements is translated into an ASG: declarations. This can be declarations of types, functions, variables, etc. Attached to a declaration is a set of comments that was found in the source code before the declaration. It is thus possible to provide other metadata (such as code documentation) as part of these comments. A variety of comment processors exist to extract such metadata from comments.