🚧 This plugin is currently in a beta-version. Feel free to test it and provide feedback! :)

🚀 bpmn-to-code

bpmn-to-code is a Maven and Gradle plugin designed to simplify process automation. Its vision is to foster clean & robust solutions for BPMN-based process automation. Therefore, it aims to provide a range of features — such as generating API definition files from BPMN process models — to reduce manual effort, simplify testing, promote the creation of clean process models, and ensure consistency between your BPMN model and your code.

🤩 What it can do for you

Streamlined Process Automation

Say goodbye to the tedious task of manually referencing BPMN elements. bpmn-to-code automatically extracts key details—like element IDs, messages, and worker types—and generates a lightweight “Process API” that keeps your process models and code in sync.

Java & Kotlin Code Generation

Whether you’re developing in Java or Kotlin, our plugin creates ready-to-use API definitions that integrate seamlessly with your testing frameworks, messaging systems, or any other automation logic.

Engine Agnostic & Extensible

Currently, bpmn-to-code supports both Camunda 7 and Zeebe. Built with extensibility in mind, it is designed so that adding support for additional process engines is straightforward—if there is enough demand.

Styleguide Validation (🚧)

Looking ahead, I’m planing a styleguide validation feature. Much like a linter for code, it will analyze your BPMN models against your custom style guide - ensuring that element IDs, message names, and task types adhere to predefined patterns and naming conventions. This will help maintain designs that are as clean and consistent as your code.

💡 Process-API generation in action

One of the key current features is generating a lightweight “Process API” for your BPMN models. Let’s say you have a newsletter subscription workflow (BPMN) that looks like this:

After running bpmn-to-code, you’ll have a Kotlin (or Java) file that programmatically references your process model. For example:

// Generated by bpmn-to-code
@file:Suppress("unused")

package de.emaarco.example

import kotlin.String
import kotlin.Suppress

@Suppress("unused")
object NewsletterSubscriptionProcessApiV1 {
    val PROCESS_ID: String = "newsletterSubscription"

    object Elements {
        val Timer_EveryDay: String = "Timer_EveryDay"
        val Timer_After3Days: String = "Timer_After3Days"
        val ErrorEvent_InvalidMail: String = "ErrorEvent_InvalidMail"
        val Activity_ConfirmRegistration: String = "Activity_ConfirmRegistration"
        val SubProcess_Confirmation: String = "SubProcess_Confirmation"
        val EndEvent_RegistrationAborted: String = "EndEvent_RegistrationAborted"
        val EndEvent_SubscriptionConfirmed: String = "EndEvent_SubscriptionConfirmed"
        val EndEvent_RegistrationCompleted: String = "EndEvent_RegistrationCompleted"
        val EndEvent_RegistrationNotPossible: String = "EndEvent_RegistrationNotPossible"
        val Activity_AbortRegistration: String = "Activity_AbortRegistration"
        val Activity_SendWelcomeMail: String = "Activity_SendWelcomeMail"
        val Activity_SendConfirmationMail: String = "Activity_SendConfirmationMail"
        val StartEvent_SubmitRegistrationForm: String = "StartEvent_SubmitRegistrationForm"
        val StartEvent_RequestReceived: String = "StartEvent_RequestReceived"
    }

    object Messages {
        val Message_FormSubmitted: String = "Message_FormSubmitted"
        val Message_SubscriptionConfirmed: String = "Message_SubscriptionConfirmed"
    }

    object TaskTypes {
        val EndEvent_RegistrationCompleted: String = "newsletter.registrationCompleted"
        val Activity_AbortRegistration: String = "newsletter.abortRegistration"
        val Activity_SendWelcomeMail: String = "newsletter.sendWelcomeMail"
        val Activity_SendConfirmationMail: String = "newsletter.sendConfirmationMail"
    }

    object Timers {
        val Timer_EveryDay: BpmnTimer = BpmnTimer("Duration", "PT1M")
        val Timer_After3Days: BpmnTimer = BpmnTimer("Duration", "PT2M30S")

        data class BpmnTimer(
            val type: String,
            val timerValue: String,
        )
    }

    object Errors {
        val Error_InvalidMail: BpmnError = BpmnError("Error_InvalidMail", "500")

        data class BpmnError(
            val name: String,
            val code: String,
        )
    }

    object Signals {
        val Signal_RegistrationNotPossible: String = "Signal_RegistrationNotPossible"
    }
}

All you need is a simple Gradle task configuration that specifies where your BPMN models reside, where to output the generated API files, which language (Java or Kotlin) to generate, and which process engine your models target (e.g., Camunda 7 or Zeebe):

tasks.named("generateBpmnModelApi", GenerateBpmnModelsTask::class) {
    baseDir = projectDir.toString()
    filePattern = "src/main/resources/**/*.bpmn"
    outputFolderPath = "$projectDir/src/main/kotlin"
    packagePath = "de.emaarco.example"
    outputLanguage = OutputLanguage.KOTLIN
    processEngine = ProcessEngine.ZEEBE
}

Once configured, bpmn-to-code automatically picks up your BPMN files and generates convenient, type-safe references you can use throughout your application—be it for testing, messaging, or worker definitions.

📦 Structure

bpmn-to-code is available for both Gradle and Maven. For detailed installation and configuration instructions, please refer to the respective module README's:

• bpmn-to-code-gradle: Gradle plugin integration for projects using Gradle.
• bpmn-to-code-maven: Maven plugin integration for projects using Maven.
• bpmn-to-code-core: Contains the core logic for parsing BPMN files and generating the API representation.
• examples: Contains gradle- & maven-example projects demonstrating how to use the plugin. They are not part of the gradle-monorepo. In case you clone the repository, I'd suggest you to open them as a separate project.

📬 Get the Plugin

You can find the plugin on either the Maven Central Repository or the Gradle Plugin Portal

🤝 Contributing

Community contributions are at the heart of bpmn-to-code’s vision. If you have ideas to improve the code generation, want to add support for a new engine, or are keen to help shape the styleguide validator, please join me on GitHub. Submit issues, open pull requests, or simply start a discussion.