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Migrate from Camunda 7 to Priostack

Last updated: 2026-04-06 · 12 min read

Concept Mapping

Before migrating, understand how Camunda 7 concepts map to Priostack equivalents.

REST API Endpoint Mapping

Migration Steps

Step 1 - Export your process definitions

From Camunda 7 Cockpit or the filesystem, collect all .bpmn and .dmn files. Priostack accepts the same XML format.

Step 2 - Remove Java-specific extensions

Camunda 7 uses Java Delegates and expression language that Priostack does not support. Strip or replace these elements:

Before (Camunda 7):

<serviceTask id="credit-check" name="Credit Check"
  camunda:class="com.example.CreditCheckDelegate" />

After (Priostack, with zeebe:taskDefinition): a fragment, to paste inside a <definitions> element that declares xmlns:zeebe="http://camunda.org/schema/zeebe/1.0".

<serviceTask id="credit-check" name="Credit Check">
  <extensionElements>
    <zeebe:taskDefinition type="credit-check" />
  </extensionElements>
</serviceTask>

Step 3 - Deploy to Priostack

curl -X POST "https://priostack.com/api/v1/process-definitions?resourceName=loan-approval.bpmn" \
  -H "X-API-Key: ps_your_key" \
  -H "Content-Type: application/xml" \
  --data-binary @loan-approval.bpmn

This route deploys BPMN only and is free. It answers 200 with a deployments array; a model that does not parse answers 422.

Step 4 - Port your External Task workers

Camunda 7 External Task workers poll /engine-rest/external-task/fetchAndLock. In Priostack, poll POST /api/v1/jobs/activate:

Camunda 7 worker (conceptual):

// fetchAndLock
POST /engine-rest/external-task/fetchAndLock
{"workerId":"w1","maxTasks":10,"topics":[{"topicName":"credit-check","lockDuration":30000}]}

Priostack worker:

// activate (answers 200 at once, {"jobs":[]} when nothing waits)
POST /api/v1/jobs/activate
{"type":"credit-check","worker":"w1","maxJobsToActivate":10}

// complete a job (answers 204 No Content)
POST /api/v1/jobs/{jobKey}/complete
{"variables":{"score":720,"approved":true}}

There is no lock duration to port. lockDuration has no equivalent: an activated job stays with the worker until it completes it or fails it, and timeout is accepted and ignored. Job keys are strings. Always send type, and sleep 1 to 5 seconds after an empty poll.

Step 5 - Migrate DMN decision tables

Camunda 7 DMN tables deploy through POST /api/v1/models, which detects the model kind and costs 1 credit (refunded if the deploy fails). Input entries must be unary tests such as "gold", > 500 or [100..500]; see DMN Elements. A table the engine cannot read answers 422.

curl -X POST "https://priostack.com/api/v1/models?resourceName=credit-score.dmn" \
  -H "X-API-Key: ps_your_key" \
  -H "Content-Type: application/xml" \
  --data-binary @credit-score.dmn

Evaluate standalone. The body is a flat JSON object of inputs, and the call costs 1 credit:

curl -X POST https://priostack.com/api/v1/decisions/creditScore/evaluate \
  -H "X-API-Key: ps_your_key" \
  -H "Content-Type: application/json" \
  -d '{"score":720,"employment":"full-time"}'

It answers {"result":{...}} with the outputs of the matched rule, as strings.

Step 6 - Update User Task handling

Camunda 7 task query and claim API maps directly:

# List open tasks (filters: status=open|claimed, definition_key=)
GET /api/v1/tasks?status=open

# Complete a task (equivalent to setVariables + complete; 1 credit on this route)
POST /api/v1/tasks/{taskId}/complete
{"variables":{"approved":true,"comment":"Looks good"}}

Step 7 - Remove Spring / CDI dependencies

If your workers were embedded in a Spring Boot app using camunda-bpm-spring-boot-starter, extract the business logic into standalone worker processes. Your workers can be any language - Priostack workers speak plain HTTP.

Unsupported Features

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