casen generate

casen generate bpmn produces BPMN 2.0 files without the interactive TUI. It has three operating modes: template, definition (full JSON), and modify-existing (patch). Auto-layout is applied in all modes.

Commands

casen generate
└── bpmn    — generate or modify a BPMN file

Template mode

Pick a built-in template by name. Use --process-id and --name to customise the identifiers.

casen generate bpmn --template minimal --process-id order --name "Order Processing"
casen generate bpmn --template approval --process-id leave-request
casen generate bpmn --template parallel --process-id enrichment --name Enrichment
casen generate bpmn --template timer-start --process-id nightly-sync

Template	Pattern
empty	Start event only — bare skeleton
minimal	Start → service task → end
user-task	Start → user task → end
call-activity	Start → call activity → end
business-rule	Start → business rule task → end
approval	Start → user task → XOR gateway → approve/reject paths
parallel	Start → parallel fork → 2 service tasks → join → end
inclusive	Start → inclusive gateway → 2 conditional tasks → merge → end
timer-start	Timer start event → service task → end
message-start	Message start event → service task → end
error-boundary	Service task with error boundary → two end events
subprocess	Start → embedded sub-process → end
event-subprocess	Process with a non-interrupting error event sub-process

Flags

Flag	Short	Description	Default
--template		Template name (see table above)	minimal
--process-id	-i	Process element ID	process
--name	-n	Process display name	—
--output	-o	Output file path (- for stdout)	<process-id>.bpmn

Definition mode (AI / scripting path)

Pass a full CompactDiagram JSON object directly. This covers all 23 BPMN element types, all event definition types, boundary events, sub-processes, and Zeebe extensions.

# Inline JSON
casen generate bpmn --definition '{"id":"Definitions_order","processes":[...]}'

# Pipe from a file or AI output
cat definition.json | casen generate bpmn --output order.bpmn

# Write to stdout
echo '{"id":"Defs","processes":[...]}' | casen generate bpmn --output -

Print the JSON schema

Run --help-schema to print the full CompactDiagram reference — element types, event types, field descriptions, and a worked example — formatted for quick AI consumption:

casen generate bpmn --help-schema

CompactDiagram structure

{
  "id": "Definitions_my-process",
  "processes": [{
    "id": "my-process",
    "name": "My Process",
    "elements": [
      { "id": "start",  "type": "startEvent",      "name": "Start" },
      { "id": "task1",  "type": "serviceTask",      "name": "Do Work", "jobType": "my-worker" },
      { "id": "gw",     "type": "exclusiveGateway", "name": "OK?" },
      { "id": "end-ok", "type": "endEvent",         "name": "Done" },
      { "id": "end-err","type": "endEvent",         "name": "Failed", "eventType": "error" }
    ],
    "flows": [
      { "id": "f1", "from": "start",  "to": "task1" },
      { "id": "f2", "from": "task1",  "to": "gw" },
      { "id": "f3", "from": "gw",     "to": "end-ok",  "condition": "= ok",      "name": "Yes" },
      { "id": "f4", "from": "gw",     "to": "end-err", "condition": "= not ok",  "name": "No" }
    ]
  }]
}

Element types — all 23 BPMN types supported:

• Tasks: serviceTask userTask scriptTask businessRuleTask callActivity sendTask receiveTask manualTask task
• Events: startEvent endEvent intermediateCatchEvent intermediateThrowEvent boundaryEvent
• Gateways: exclusiveGateway parallelGateway inclusiveGateway eventBasedGateway complexGateway
• Containers: subProcess adHocSubProcess eventSubProcess transaction

Event types (eventType field on event elements): timer message signal error escalation terminate cancel conditional link compensate

Zeebe extensions:

Field	Applies to	Effect
jobType	serviceTask, sendTask	Sets zeebe:taskDefinition.type
taskHeaders	serviceTask, sendTask	Sets zeebe:taskHeaders key/value pairs
resultVariable	serviceTask, businessRuleTask	Maps connector response to a variable
calledProcess	callActivity	Sets zeebe:calledElement.processId
formId	userTask	Sets zeebe:formDefinition.formId
decisionId	businessRuleTask	Sets zeebe:calledDecision.decisionId

HTTP connector shorthand:

{
  "id": "http1",
  "type": "serviceTask",
  "name": "Call API",
  "jobType": "io.camunda:http-json:1",
  "taskHeaders": {
    "url": "https://api.example.com/orders",
    "method": "POST"
  },
  "resultVariable": "apiResponse"
}

Modify-existing mode (--input)

Load an existing .bpmn file and patch it — add elements and flows, then re-apply auto-layout. The default output overwrites the input file.

Inspect the current state

Use --dump-compact to print the file’s CompactDiagram JSON. Use this to discover existing element IDs before writing a patch.

casen generate bpmn --input order.bpmn --dump-compact

Output is a CompactDiagram JSON object — the same format accepted by --definition.

Add elements and flows

# Add a rejection path to an existing gateway with id "gw"
casen generate bpmn --input order.bpmn \
  --patch '{"elements":[
    {"id":"notify",     "type":"serviceTask","name":"Notify Customer","jobType":"notify-worker"},
    {"id":"end-reject", "type":"endEvent",   "name":"Rejected"}
  ],"flows":[
    {"id":"fn1","from":"gw",     "to":"notify",     "condition":"= not approved","name":"No"},
    {"id":"fn2","from":"notify", "to":"end-reject"}
  ]}'

Patch mode appends to the first process in the file. Flows in the patch can reference existing element IDs — they are not required to be new.

Pipe a patch from AI output

# AI generates the patch JSON, pipe it in
echo '{"elements":[...],"flows":[...]}' | casen generate bpmn --input order.bpmn

Normalize layout

Run --input without --patch to re-apply auto-layout without changing the process model:

casen generate bpmn --input messy.bpmn --output clean.bpmn

Flags for --input mode

Flag	Description	Default
--input / -f	Existing .bpmn file to load	—
--patch	JSON patch: {"elements":[...],"flows":[...]}	—
--dump-compact	Print CompactDiagram JSON of --input and exit	—
--output / -o	Output path (- for stdout)	Overwrites --input file

Typical AI workflow

# 1. Inspect the existing file — AI learns element IDs
casen generate bpmn --input order.bpmn --dump-compact

# 2. Check the schema if needed
casen generate bpmn --help-schema

# 3. AI generates patch JSON and pipes it in
echo '{"elements":[...],"flows":[...]}' | casen generate bpmn --input order.bpmn

# 4. Verify the result
casen view bpmn order.bpmn