Developed a foundational Abstract Syntax Tree (AST) for the HRW4U linter within the apache/trafficserver repository, enabling robust static analysis and future code generation. The work centered on designing a precise, test-backed AST model in Python, covering statements, expressions, control flow, and top-level constructs. Leveraging ANTLR for parsing, an ASTVisitor was implemented to translate parse trees into the new AST, with safeguards for grammar drift. Comprehensive tests validated AST construction, visitor behavior, and line-number tracking across multiple node types. The project also introduced concrete value types to preserve semantic distinctions, improving maintainability and setting the stage for automated transformations.