Hi Pre-friends. I wonder if I could ask for some help. I am working on a project using Prefect Core, and am trying to create a Flow-of-Flows. The documentation says of

StartFlowRun

:

Task used to kick off a flow run using Prefect Core’s server or Prefect Cloud. If multiple versions of the flow are found, this task will kick off the most recent unarchived version.

(Emphasis mine.) The problem I’m having is this: if I instantiate StartFlowRun with a

project_name

, I get:

Malformed response received from Cloud - please ensure that you have an API token properly configured.

If I instantiate it without specifying a

project_name

, at runtime I see:

raise ValueError("Must provide a project name.")

raised from

StartFlowRun

Hi @Matt Gordon - a couple quick questions: 1. What version of Prefect Server are you running? 2. What version of Prefect is your flow using? 3. Have you run

prefect backend server

before running your script?

Nicholas, thanks for taking the time to answer. I’m using

prefect==0.13.19

for our execution. Up until now, I have not needed to run Prefect Server to run any of my flows. It sounds like using StartFlowRun will require me to run the backend server?

Ahh gotcha. Yes, in order to use

StartFlowRun

, you'll need to be using a backend (Server or Cloud). If you're working with Core-only, there's no central arbiter of flow state. In addition,

flow.run

doesn't support concurrent flow runs so your only option is to call out to another script where a separate flow is defined (with

python other_flow.py

)

Okay. It sounds like ,for the moment, the simplest thing for me if I just want to run a simple set of dependent flows is to just run them in order, and cache the

Result

in between them to pass the data along.

That sounds right - if you can get away with that locally that would be the easiest way to get started

Great thanks