casen migrate — BPMN Kit Docs

casen migrate c7 converts Camunda 7 models to Camunda 8. It rewrites what it can rewrite mechanically and reports every Camunda 7 construct it finds, one line per element. The migration guide explains what is converted and why.

casen migrate c7 order.bpmn

order.bpmn → order.c8.bpmn
  19 convertible · 8 manual · 2 unsupported

  UNSUPPORTED
    order-fulfillment  camunda:historyTimeToLive
      Camunda 8 has no per-process history time to live (was "180").
      → Configure data retention for the cluster (Operate, Tasklist and Optimize archiving).
    …
  MANUAL
    Task_ship  camunda:class
      Java delegate class "com.acme.orders.ShipOrderDelegate" runs inside the Camunda 7 engine; …
      → Implement a job worker for type "shipOrderDelegate" …
    …
  CONVERTIBLE
    Task_charge  camunda:type=external
      External task topic "charge-payment" became job type "charge-payment".
    …

The groups come in order of work: unsupported (Camunda 8 has no equivalent), manual (Camunda 8 has one, but a person must write or check it), convertible (done).

A model Camunda 8 would refuse

The converted model must deploy. When Zeebe would reject it, nothing is written, the report is still printed, and the reasons come first:

order.bpmn
  ✖ Not deployable on Camunda 8.10: 2 error(s)
    - Message_PaymentConfirmed: Must have exactly one zeebe:subscription extension element (zeebe/message-subscription)
    - Task_summary: Must have either one 'zeebe:script' or one 'zeebe:taskDefinition' extension element (zeebe/script-task-implementation)
    Nothing written. Pass --placeholders to fill placeholder values (reported as manual
    work to replace), or --no-validate to write the model as it is.
  19 convertible · 8 manual · 2 unsupported
  …

The command exits 1 with 1 of 1 file would not deploy on Camunda 8 — pass --placeholders or --no-validate. With --placeholders, each value the conversion could not derive (a job type, a correlation key) gets a placeholder such as placeholder-Task_summary, listed under MANUAL as placeholder jobType; replace it before going live. In JSON, a refused file has "refused": true, the error, and the counts and findings of the report.

Where the output goes

By default, each name.bpmn is written to name.c8.bpmn beside it. The Camunda 7 file is never changed.
With --out <dir>, files are written to that directory under their own names. The directory is created if it does not exist.
An existing output file is never overwritten unless you pass --force. The command reports the file and exits 1.

The output keeps the source file’s formatting and element order, so a text diff against the Camunda 7 file shows only what the migration changed.

Flags

Flag	Default	What it does
`--out <dir>`	beside the input	Write converted files to this directory
`--check`	off	Report only. Write nothing, and exit 1 if any `manual` or `unsupported` finding remains
`--format`	`text`	`text` or `json`
`--force`	off	Overwrite converted files that already exist
`--placeholders`	off	Fill placeholder values the conversion cannot derive, instead of refusing the model
`--no-validate`	validate	Write the converted model even when Camunda 8 would not deploy it

Put the flags after the file names: casen migrate c7 models/*.bpmn --check.

As a pipeline gate

casen migrate c7 models/*.bpmn --check --format json

The JSON is an array with one entry per file: file, output (null with --check), counts, and findings. Each finding has elementId, elementType, processId, construct, severity, message, suggestion, and applied. applied tells you if the converter wrote a Camunda 8 equivalent. A file that already targets Camunda 8, or that cannot be read, is reported with an error and makes the command exit 1.