< Marvin> My flow s code contains as a decorator ``` flow de Prefect Community #ask-marvin

<@ULVA73B9P> My flow's code contains as a decorato...

Romain Lefebvre

11/06/2025, 10:00 AM

@Marvin My flow's code contains as a decorator :

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@flow(
    description="...",
    name="iuep-pipeline",
    flow_run_name="iuep-pipeline-{org_id}",
)

And in my prefect.yaml :

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- name: "iuep-pipeline-{{ $ORG_ID }}"
    tags:
      - "{{ $TENANT_ID }}"
      - "{{ $ORG_ID }}"
    entrypoint: app/flows/iuep_pipeline.py:iuep_pipeline
    work_pool:
      name: "{{ $WORK_POOL_NAME }}"
      job_variables: 
        env: *env-vars
    parameters:
      org_id: "{{ $ORG_ID }}"
    schedules:
        - cron: "{{ $SCHEDULE_CRON }}"
          slug: "scheduled-iuep"
          timezone: "{{ $SCHEDULE_TIMEZONE }}"
          active: true
    pull:
      - prefect.deployments.steps.set_working_directory:
          directory: /app

So as you can see, I've configure the flow name, the flow run name and the slug name of that scheduled deployment set to

scheduled-iuep

but the next run flow run name is a random name, why ? how can I use the defined flow run name template ? sBut when I deploy it and I go to the UI, I can see my deployment with the right name, the scheduling name set to

Marvin

11/06/2025, 10:00 AM

✅ thought for 508.4 seconds

Marvin

11/06/2025, 10:09 AM

Short answer: this is expected. In Prefect 3.x, the

flow_run_name

template on the

@flow

decorator is applied by the worker when the flow actually starts. The UI will show a randomly generated placeholder for “Next run” and scheduled runs until the run begins; then it’s renamed to your template (e.g.,

iuep-pipeline-<org_id>

). A couple of notes specific to your config: - The schedule

slug: "scheduled-iuep"

is just an identifier for the schedule, not the run name. - The deployment

name

is the deployment’s name, also not the run name. - The

@flow(flow_run_name="iuep-pipeline-{org_id}")

is the correct way to template run names; it will use the run’s parameters. If you still see a random name after the run starts, double-check: - Your flow signature has a parameter named exactly

org_id

, e.g.:

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@flow(
      description="...",
      name="iuep-pipeline",
      flow_run_name="iuep-pipeline-{org_id}",
  )
  def iuep_pipeline(org_id: str):
      ...

- Your deployment is passing that parameter (which you are with

parameters: { org_id: "{{ $ORG_ID }}" }

). - At runtime,

org_id

is actually present. You can log/verify:

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from prefect import get_run_context

  @flow(flow_run_name="iuep-pipeline-{org_id}")
  def iuep_pipeline(org_id: str):
      ctx = get_run_context()
      print("Flow parameters:", ctx.parameters)  # should include 'org_id'

Optional: If you need to programmatically set or adjust the name during the run, you can do so:

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from prefect.client.orchestration import get_client
from prefect.runtime import flow_run

@flow
def iuep_pipeline(org_id: str):
    with get_client(sync_client=True) as client:
        client.set_flow_run_name(flow_run.id, f"iuep-pipeline-{org_id}")

Docs for reference: - Custom flow run names - prefect.runtime.flow_run Can you confirm whether the name remains random after the run starts, and share your flow function signature if so? That will help pinpoint if the template isn’t resolving (usually due to a parameter name mismatch).

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