Vert.x 4 comes with plenty of new exciting features, some of them have been developed in Vert.x 3 and made available as tech previews.

Here is an overview of the most important features supported in Vert.x 4.

User experience

Vert.x 4 has been designed to improve user experience and API’s usability while keeping it fast, un-opinionated, and most importantly fun!

Callback to the Future

Get away from callback hell and use the power of Vert.x 4 futures.

Microservices monitoring

Vert.x Tracing supports both Opentracing and Zipkin. It also complements Vert.x Metrics.

Reactive SQL clients

High-performance reactive SQL clients, fully integrated with Vert.x Metrics and Vert.x Tracing.

Reactive Redis client

The revamped client API now supports all Redis connection modes, single, sentinel and cluster, with full and extensible support for Redis commands.

SQL templating

SQL Client Templates is a library designed to facilitate building SQL queries.

Web

Web sessions can now be stored on a external backend such as Redis.

Web routing experience has been improved.

Web validation has never been so easy using the latest Json Schema standards thanks to Vert.x Web validation.

OpenAPI

The revamped OpenAPI implementation uses Web validation to enforce Contract Driven Development.

Authentication and Authorization

A set of new modules are available

• vertx-auth-properties and vertx-auth-ldap to replace the deprecated shiro auth.
• vertx-auth-sql to work with reactive sql clients instead of blocking jdbc clients.
• vertx-auth-webauth as a FIDO2 verified implementation of FIDO2/Webauthn Relay Party.

The vertx-auth-oauth2 module now supports PKCE as an extra layer of security to your application.

JSON Web Tokens (JWT) and JSON Web Keys (JWK) have been enhanced to support more algorithms, EC, RS and PS as well as now fully support certificate chain validations, enabling better verifications.