JSON Schema Validator for Ruby

This library lets Ruby developers check whether their data matches a specific structure or format. Think of it like a template validator—you define what shape your data should have (a schema), and the tool tells you if your actual data fits that shape. For example, you might say "I expect an object with a required field 'a' that must be an integer," and the validator will pass or fail your data against that rule.

The validator works in three ways depending on what you need. You can get a simple true/false answer, throw an error with a helpful message about what went wrong, or get back a list of all validation problems at once. It's flexible about input too—you can validate Ruby objects, JSON strings, or even load schemas and data from files. By default it uses the JSON Schema Draft 4 standard, but it also supports older versions (Draft 1, 2, and 3) if you need backward compatibility.

The tool is meant for developers building APIs, data pipelines, or any system where you need to enforce that incoming data has the right structure. A backend engineer might use it to validate API requests before processing them, or a data engineer might validate rows in a batch job before loading them into a database. It catches mistakes early—like someone sending the number 5 when you expected a string, or missing a required field entirely.

What makes this library flexible is that you're not limited to the standard validation rules. The README shows how to extend it with custom validation logic, add your own format checkers (like validating custom patterns or business rules), and control how it handles external schemas. You can also control security by limiting what URLs or files it's allowed to read, which matters if you're validating untrusted input.