Migrate from Camunda 7 to Priostack

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

Priostack is compatible with BPMN 2.0 and DMN 1.3. Most Camunda 7 process models load without modification — only the worker API and deployment method change.

Concept Mapping

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

Camunda 7	Priostack	Notes
Process Engine (embedded/server)	Priostack Engine (hosted)	No local JVM required
External Task Pattern	Job Worker (polling)	Same poll-activate-complete cycle
Java Delegate / Expression	Service Task + worker	Move logic to a worker process
Cockpit (monitoring)	Dashboard / Console	Web UI + REST API
Tasklist (user tasks)	`/tasklist`	Same task claim/complete model
REST API `/engine-rest`	`/api/v1`	Different paths — see mapping below
DMN Engine (decision tables)	Built-in DMN 1.3 evaluation	`POST /api/v1/decisions/evaluate`
Form Fields (embedded forms)	Variable map in task complete	Pass `variables` in `POST /api/v1/tasks/{key}/complete`
Tenants (multi-tenancy)	Per-account isolation	Each API key = one tenant namespace

REST API Endpoint Mapping

Camunda 7 endpoint	Priostack equivalent
`POST /engine-rest/deployment/create`	`POST /api/v1/deployments`
`POST /engine-rest/process-definition/{id}/start`	`POST /api/v1/process-instances`
`GET /engine-rest/process-instance`	`GET /api/v1/process-instances`
`GET /engine-rest/external-task`	`POST /api/v1/jobs/activate` (poll model)
`POST /engine-rest/external-task/{id}/complete`	`POST /api/v1/jobs/{key}/complete`
`POST /engine-rest/external-task/{id}/failure`	`POST /api/v1/jobs/{key}/fail`
`GET /engine-rest/task`	`GET /api/v1/tasks`
`POST /engine-rest/task/{id}/complete`	`POST /api/v1/tasks/{key}/complete`
`POST /engine-rest/message`	`POST /api/v1/messages`
`POST /engine-rest/decision-definition/{id}/evaluate`	`POST /api/v1/decisions/evaluate`

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:

Remove camunda:class, camunda:expression, camunda:delegateExpression from Service Tasks. Replace with zeebe:taskDefinition type="your-worker-type".

Before (Camunda 7):

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

After (Priostack / Zeebe-compatible):

<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/deployments \
  -H "X-API-Key: ps_your_key" \
  -H "Content-Type: application/xml" \
  --data-binary @loan-approval.bpmn

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
POST /api/v1/jobs/activate
{"type":"credit-check","worker":"w1","maxJobsToActivate":10,"timeout":30000}

// complete a job
POST /api/v1/jobs/{jobKey}/complete
{"variables":{"score":720,"approved":true}}

Step 5 — Migrate DMN decision tables

Camunda 7 DMN 1.1/1.3 tables are fully compatible. Deploy them alongside BPMN or standalone:

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

Evaluate standalone:

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

Step 6 — Update User Task handling

Camunda 7 task query and claim API maps directly:

# List open tasks
GET /api/v1/tasks?process_instance_id={instanceKey}

# Complete a task (equivalent to setVariables + complete)
POST /api/v1/tasks/{taskKey}/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

Camunda 7 feature	Status in Priostack
Embedded subprocess history (full audit trail)	Instance state + events — no fine-grained history DB
BPMN compensation events	Not yet supported (roadmap)
Script tasks (Groovy, JavaScript)	Not supported — use a worker process instead
Case execution (CMMN 1.0 embedded in Camunda 7)	CMMN 1.1 supported as a separate deployment
Batch operations API	Not yet supported

Need help migrating a specific model? Contact support@priostack.com with your BPMN file and the current Camunda 7 behavior you need to preserve.

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