Show HN: AST-guard – Fast, zero-cost structural checks for LLM code execution (github.com)

The recent release of **ast-guard** has introduced a groundbreaking pre-execution gate for AI-generated code, aimed at enhancing safety in code execution environments. This tool acts as a deterministic layer that analyzes generated code by parsing it into an Abstract Syntax Tree (AST) and delivering an immediate verdict—free of costs and under 10 milliseconds—before execution begins. Unlike traditional linters or security scanners, ast-guard provides a structural check that is not susceptible to manipulation by AI models, effectively filling critical gaps in existing defense mechanisms. ast-guard is significant for the AI/ML community as it leverages structural analysis to catch straightforward vulnerabilities and code anomalies with near-perfect specificity. It operates in two modes: *Pair Mode*, which compares original and generated code to detect deviations, and *Standalone Mode*, which analyzes single outputs using behavioral risk scoring. With impressive detection rates of 95% or higher in various benchmarks, ast-guard empowers developers to focus on semantic evaluation while it manages structural integrity, thus promoting safer AI-driven coding practices. This advancement is a complementary layer to existing approaches, paving the way for more robust code generation and deployment in AI applications.