@Marvin easiest way to espose flow as rest api with params?

To expose a Prefect flow as a REST API with parameters, you can utilize the

serve

function from Prefect's top-level API. This feature allows you to run a flow as a service, accepting HTTP requests with parameters to trigger the flow. Here’s a brief overview of how you might achieve this: 1. Define Your Flow: Ensure your flow is defined with parameters. Prefect supports both positional and keyword arguments for flow parameters. 2. Use Prefect's

serve

Feature: Prefect provides a

serve

function that can be used to expose a flow as a REST API. This function listens for HTTP requests and executes the flow with the provided parameters. 3. Handle Parameters: When you trigger the flow via the REST API, you can pass parameters in the request. Prefect will automatically handle the type conversion of these inputs. For more detailed instructions and examples, you can refer to the Prefect documentation on writing flows. If you're using Prefect 3.x, here’s a quick way to get started with the

serve

function:

python
from prefect import flow, serve

@flow
def my_flow(param1, param2):
    # Your flow logic here
    pass

serve(my_flow)

This code snippet will expose

my_flow

as a REST API, allowing you to trigger it with parameters via HTTP requests. For more details on the

serve

function, you can explore the Prefect API documentation or the source code here.

@Marvin follow up question, how to do this if I am using self hosted prefect and use yaml for deployment of flows?

To expose a flow as a REST API using a self-hosted Prefect setup and deploy it with a YAML configuration, you'll need to follow these steps: 1. Self-hosted Prefect Server: Ensure you have a Prefect server running locally or on your infrastructure. You can start it using the

prefect server start

command. More details are available in the self-hosting guide. 2. Define Your Flow: Create your flow in Python, ensuring it accepts parameters as needed. 3. Create a YAML Deployment: Define your deployment in a

prefect.yaml

file. This file allows you to configure how and where your flow runs, including infrastructure settings. 4. Deploy the Flow: Use the

prefect deploy

command with your YAML file to deploy the flow. This will set up the flow on your Prefect server, making it available for execution via the API. Here's a basic example of what your

prefect.yaml

might look like:

yaml
version: 1
flows:
  - name: my-flow
    parameters:
      param1: default_value1
      param2: default_value2
deployments:
  - name: my-deployment
    flow: my-flow
    schedule:
      cron: "* * * * *"  # Example cron schedule
    infrastructure:
      type: process

5. Trigger Flow via API: Once deployed, you can trigger your flow using the Prefect API. You can specify parameters in the API request to customize each flow run. For more details on deployments and YAML configurations, visit the Prefect deployment documentation. By following these steps, you can effectively expose your flow as a REST API while using a self-hosted Prefect setup and YAML for deployment.