Migrate from Camunda 7

This guide walks you through migrating an existing Camunda Platform 7 application to Priostack. Most migrations can be completed in a day for small projects, or a week for large enterprise deployments.

Section 1: What's Compatible

Priostack supports BPMN 2.0, so your existing process diagrams transfer with minimal changes:

• All standard BPMN 2.0 elements (tasks, gateways, events, subprocesses)
• Sequence flow conditions using FEEL expressions
• Timer events with ISO 8601 durations and cycle expressions
• Message correlation (with updated correlation key syntax)
• Signal events (broadcast and catch)
• Error boundary events and escalation events
• Compensation handlers
• Multi-instance tasks (parallel and sequential)
• DMN 1.3 decision tables

Section 2: What's Different

Section 3: Migration Steps

Step 1: Export Your BPMN Files

From Camunda Modeler or Cockpit, export all your BPMN files as .bpmn XML files. Keep DMN files too.

Step 2: Remove Camunda-Specific Extensions

Open each BPMN file and replace Camunda 7 extension elements:

<serviceTask id="validateOrder"
  camunda:class="com.example.ValidateOrderDelegate"
  camunda:asyncBefore="true" />

<serviceTask id="validateOrder"
             name="Validate Order">
  <extensionElements>
    <zeebe:taskDefinition
      type="validate-order"
      retries="3" />
  </extensionElements>
</serviceTask>

<userTask id="review"
  camunda:assignee="${reviewer}"
  camunda:candidateGroups="managers" />

<userTask id="review" name="Review Order">
  <extensionElements>
    <zeebe:userTask>
      <zeebe:assignee>=reviewer</zeebe:assignee>
      <zeebe:candidateGroups>
        managers
      </zeebe:candidateGroups>
    </zeebe:userTask>
  </extensionElements>
</userTask>

Step 3: Rewrite Java Delegates as Workers

For each Java Delegate class, create an equivalent external worker in Go, Python, or JavaScript. See the Workers Guide.

@Component
public class ValidateOrderDelegate
    implements JavaDelegate {

  @Autowired
  private OrderService orderService;

  @Override
  public void execute(DelegateExecution exec) {
    String orderId = (String) exec
        .getVariable("orderId");
    boolean valid = orderService.validate(orderId);
    exec.setVariable("orderValid", valid);
  }
}

func processJob(job Job) (map[string]interface{}, error) {
  orderId, _ := job.Variables["orderId"].(string)

  // Call your existing service
  valid, err := orderService.Validate(orderId)
  if err != nil {
    return nil, err
  }
  return map[string]interface{}{
    "orderValid": valid,
  }, nil
}

Step 4: Update API Calls

POST /engine-rest/process-definition
     /key/order-processing/start
{
  "variables": {
    "orderId": { "value": "123", "type": "String" }
  }
}

POST /api/v1/process-instances
X-API-Key: your_key
{
  "bpmnProcessId": "order-processing",
  "variables": {
    "orderId": "123"
  }
}

Step 5: Deploy and Test

# Deploy your updated BPMN
curl -X POST https://api.priostack.com/api/v1/process-definitions \
  -H "X-API-Key: your_key" \
  -H "Content-Type: application/xml" \
  --data-binary @order-processing.bpmn

# Start your workers
export PRIOSTACK_API_KEY=your_key
go run worker.go

# Start a test instance
curl -X POST https://api.priostack.com/api/v1/process-instances \
  -H "X-API-Key: your_key" \
  -d '{"bpmnProcessId":"order-processing","variables":{"orderId":"TEST-001"}}'

Section 4: Feature Mapping