What is Teki?

Teki helps you describe the shape of Java objects and validate them with a small, fluent API. It is designed for teams that like the ergonomics of JavaScript validators such as Zod or Yup, but want that style inside a Java codebase.

You can define schemas in code, scan validation annotations from model classes, validate nested objects and arrays, normalize values with rules such as trim() and defaultValue(...), and collect structured field errors when validation fails.

What Teki is for

• Validating request DTOs, config objects, command payloads, and JSON-mapped Java classes
• Keeping validation close to the data it protects
• Building reusable schemas with a fluent builder
• Using annotations when the model class should carry its own constraints
• Returning structured errors by field name instead of one opaque message

Two ways to define validation

Use the builder API when you want schemas that read like code:

import dev.ditsche.teki.Teki;

import static dev.ditsche.teki.rule.builder.Rules.*;

Teki userSchema = Teki.fromRules(
    string("email").required().email().trim(),
    string("displayName").required().min(2).max(80),
    number("age").min(13)
);

Use annotations when the constraints naturally belong on the class:

import dev.ditsche.teki.annotation.Email;
import dev.ditsche.teki.annotation.Required;
import dev.ditsche.teki.annotation.Trim;

public class SignupRequest {
    @Required
    @Email
    @Trim
    private String email;
}

Teki.from(SignupRequest.class).validate(request);

Where to go next