Teki

Fluent schema validation for Java.

Teki is an open source Java library for validating objects with a fluent builder API or annotations. Define field-level constraints on DTOs, records, and nested objects and get structured, human-readable errors back without framework dependencies.

Read the documentation • Getting Started • GitHub Releases

Why Teki

• Fluent builder API and annotation-based validation in one library
• Structured field errors with stable type identifiers
• Nested objects, arrays, and conditional rules
• Value normalization — trim, default, and transform during validation
• No framework dependencies, works with plain Java, Spring Boot, and more

Installation

<dependency>
  <groupId>dev.ditsche</groupId>
  <artifactId>teki</artifactId>
  <version>1.0.1</version>
</dependency>

Requires Java 17+.

Quick Example

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

Teki schema = Teki.fromRules(
    string(Request::getEmail).required().email().trim(),
    string(Request::password).required().min(8),
    number("age").required().positive()
);

Request result = schema.validate(request);
// or
ValidationOutcome<Request> result = schema.check(request);

Development

Contributions are welcome.

• Run the Java tests with mvn test
• Start the docs app with cd docs && pnpm dev
• Use the docs site for the full guides and API explanations: teki.ditsche.dev

If you want to contribute, opening an issue or pull request with a small focused change is the easiest way to get started.