Valgen

Valgen is a term used in software development to refer to tools and libraries that generate validation logic, constraints, and test data. The name combines validation and generation, reflecting its core purpose: to automate the creation of inputs and rules that enforce correctness. In practice, valgen platforms are used to help ensure data integrity, API contract compliance, and robust test coverage.

Common capabilities include schema-driven data generation, constraint solving, and code generation for validators in multiple programming languages. A valgen workflow typically starts with a schema or set of constraints, then produces either valid input samples, invalid samples for negative testing, or source code that enforces the rules at runtime. Some implementations integrate with existing testing frameworks and CI pipelines to automate test generation and validation checks.

Valgen tools may rely on constraint solvers, probabilistic models, or rule-based engines to balance realism with coverage. They often support deterministic seeds for reproducibility and can export outputs as data files, test harnesses, or language-specific validator modules. While valuable for accelerating quality assurance, valgen outcomes depend on the completeness of the supplied constraints and the representativeness of generated data.

See also: data validation, test data generation, property-based testing, code generation, schema validation.