Quarkus Flow

Quarkus Flow is a lightweight, low-dependency, production-grade workflow engine for Quarkus, built on the CNCF Serverless Workflow specification.

Use it to model classic workflows and Agentic AI orchestrations, with first-class CDI/Quarkus ergonomics.

📚 Full docs: https://docs.quarkiverse.io/quarkus-flow/dev/

Why Quarkus Flow?

• 🧩 CNCF-compliant workflows via a fluent Java DSL
• ⚡ Fast start & low footprint (Quarkus/native-friendly)
• 🔌 CDI-first: build-time discovery → CDI injection, no registries to wire
• 🧪 Great DX: inject your workflow class or the compiled WorkflowDefinition
• 🤝 Agentic AI ready: seamless LangChain4j integration

Quick start

Add the dependency:

<dependency>
  <groupId>io.quarkiverse.flow</groupId>
  <artifactId>quarkus-flow</artifactId>
  <version>RELEASE</version>
</dependency>

Create a workflow (extend io.quarkiverse.flow.Flow):

import jakarta.enterprise.context.ApplicationScoped;
import io.quarkiverse.flow.Flow;
import io.serverlessworkflow.api.types.Workflow;
import io.serverlessworkflow.fluent.func.spec.FuncWorkflowBuilder;
import static io.serverlessworkflow.fluent.func.dsl.FuncDSL.*;

@ApplicationScoped
public class HelloWorkflow extends Flow {
  @Override
  public Workflow descriptor() {
    return FuncWorkflowBuilder.workflow("hello")
      .tasks(set("{ message: \"hello world!\" }"))
      .build();
  }
}

Run:

./mvnw quarkus:dev

Messaging (TL;DR)

No extra artifact needed—auto-activates if you add a connector like Kafka:

<dependency>
  <groupId>io.quarkus</groupId>
  <artifactId>quarkus-messaging-kafka</artifactId>
</dependency>

Then configure:

quarkus.flow.messaging.defaults-enabled=true
mp.messaging.incoming.flow-in.connector=smallrye-kafka
mp.messaging.outgoing.flow-out.connector=smallrye-kafka

See the Messaging doc for full details.

Examples

• examples/newsletter-drafter – agentic workflow (drafter + critic + HITL)
• Docs snippets under docs/modules/ROOT/examples/

Contributing

Issues & PRs welcome! Please:

• run ./mvnw -q -DskipTests install before opening PRs
• keep docs in docs/ (Antora). Dev locally with:

./mvnw -pl docs -am quarkus:dev
# press 'w' when Quarkus starts to open the docs site

License: Apache-2.0