Creating a Process Instance

The recommended pattern is to obtain keys from a prior API response (e.g. a deployment) and pass them directly — no manual lifting needed:

from camunda_orchestration_sdk import CamundaClient
from camunda_orchestration_sdk.models.process_creation_by_key import ProcessCreationByKey

with CamundaClient() as client:
    # Deploy and capture the typed key
    deployment = client.deploy_resources_from_files(["process.bpmn"])
    process_key = deployment.processes[0].process_definition_key

    # Use it directly — the type flows through without conversion
    result = client.create_process_instance(
        data=ProcessCreationByKey(process_definition_key=process_key)
    )
    print(f"Process instance key: {result.process_instance_key}")

If you need to restore a key from external storage (database, message queue, config file), wrap the raw string with the semantic type constructor:

from camunda_orchestration_sdk import CamundaClient, ProcessDefinitionKey
from camunda_orchestration_sdk.models.process_creation_by_key import ProcessCreationByKey

with CamundaClient() as client:
    stored_key = "2251799813685249"  # from a DB row or config
    result = client.create_process_instance(
        data=ProcessCreationByKey(process_definition_key=ProcessDefinitionKey(stored_key))
    )
    print(f"Process instance key: {result.process_instance_key}")