# Probatio

> A modern, maintained Python data validation library, and a drop-in replacement for voluptuous.

Probatio validates arbitrary Python data against a schema that is itself data: plain types, dicts, lists, and callables. It is a clean-room reimplementation of voluptuous with the same public API, so changing `import voluptuous` to `import probatio` keeps existing schemas working, and it is pure Python with no native extension.

Beyond voluptuous it adds schemas built from your own dataclasses and TypedDicts (with statically typed results), JSON Schema, OpenAPI, and field-list codecs, a structured error model with stable translation keys, and an opt-in compiled engine.

Everything public is importable straight from the `probatio` package.

## Documentation Sets

- [Abridged documentation](https://probatio.frenck.dev/llms-small.txt): a compact version of the documentation for Probatio, with non-essential content removed
- [Complete documentation](https://probatio.frenck.dev/llms-full.txt): the full documentation for Probatio
- [Guides](https://probatio.frenck.dev/_llms-txt/guides.txt): How-to walkthroughs: the validation model, dict and sequence schemas, combinators, the built-in validators, error handling, custom validators, the probatio decorator, recursive, compiled, and lazy schemas, dataclass and TypedDict schemas, and the JSON Schema, OpenAPI, and field-list codecs.
- [Recipes](https://probatio.frenck.dev/_llms-txt/recipes.txt): End-to-end task recipes: validating Home Assistant config, a config file, and web API requests, LLM tool calling and MCP, and a cookbook of smaller patterns.
- [API reference](https://probatio.frenck.dev/_llms-txt/api-reference.txt): Reference material: the API surface, built-ins by role, the error classes and their translation keys, voluptuous compatibility, typing, and performance.
- [Project](https://probatio.frenck.dev/_llms-txt/project.txt): About the project: why it exists, the architecture, the security model, the comparison to alternatives, who uses it, the stability and 1.0 policy, credits, and the license.

## Notes

- The complete documentation includes all content from the official documentation
- The content is automatically generated from the same source as the official documentation