Define it

Genroc processes are defined via .genroc.yaml files. If you’ve just initialized your project with genctl init, you will see hello.genroc.yaml in the definitions folder.

# definitions/hello.genroc.yaml
nameUnique process identifier.: helloUnique process identifier.
input_schemaJSON Schema used to validate the input payload when starting a new instance.:
  typeThe value's JSON type, or a list of types it may take.: objectThe value's JSON type, or a list of types it may take.
  propertiesThe named members of an object, each a schema.:
    who: { typeThe value's JSON type, or a list of types it may take.: stringThe value's JSON type, or a list of types it may take., defaultThe value used when this one is absent. Annotation only — it does not make a required property optional.: "world" }
tasksOrdered list of execution tasks. Control advances linearly unless a switch case redirects.:
  - idTask identifier, unique within the definition.: greetTask identifier, unique within the definition.
    outputtasks.greet.output — object{greeting}:
      greetinggreeting — string: "hello, ${inputinput → object{who}.whoinput.who → string}"
    switchRequired. Routing: a shorthand ("next", "end", "$task-id") or an ordered list of cases.:
      - goto"end" to terminate, "next" to advance, or "$task-id" to jump to a task.: end"end" to terminate, "next" to advance, or "$task-id" to jump to a task.

outputoutputs.greet → object{greeting}: "$: outputsoutputs → object{greet}.greetoutputs.greet → object{greeting}"

Apply it

Genroc server now doesn’t know about this process, we first need to apply it.

Full command to do this:

genctl apply -f definitions/hello.genroc.yaml

Init project makes this easier for you, if you look into .genroc file, it has a glob for definitions. When you have setup like this, you can run the command without specifying the file.

genctl apply        # uses definitions glob from .genroc

You can also list existing definitions with genctl definitions

> genctl definitions
NAME   VERSION  REGISTERED  BY                 RAISES
hello  v1       just now    no-auth:anonymous  

Run it

You can now run the definition with a run command:

genctl run hello --input '{"who": "genroc user"}'

The command creates an instance of our hello process.

Processes accept input in the form of JSON.

You can use an equivalent, more user friendly version with the --set parameter:

genctl run hello --set "who=genroc user"

If the instance starts correctly, genctl will print a summary with an instance id.

> genctl run hello --set "who=genroc user"
started: 4cqpdx8z  hello@v1  (running)

Checking the instance state

We can now check the instance status with get command and the instance id.

genctl get 4cqpdx8z
# or
genctl get @last

But a more convenient way is to use @last alias, which will use the last instance id that was created.

> genctl get @last
ID:       4cqpdx8z
Process:  hello@v1
Status:   completed
Task:     greet
Created:  2026-09-08 13:44:24  (just now)
Updated:  2026-09-08 13:44:24  (just now)

Output:
greeting: hello, genroc user

The example process basically just copies your input and prints it out into the output. So it finishes instantly.

@last alias is genctl shorthand, it works only on the same machine that started the process

Checking the logs

The instance also produces logs which you can list through logs command (@last works as well).

> genctl logs @last
TIME      LEVEL  ID        EVENT             TASK
--- 2026-09-08 +02:00 ---
13:44:24  INFO   4cqpdx8z  inst_created                      by=no-auth:anonymous input={"who":"genroc user"}
13:44:24  INFO   4cqpdx8z  inst_completed    greet           output={"greeting":"hello, genroc user"}

You can see what was the input and what is the final output.