@Marvin how to trigger a flow with api webhook in prefect server?

You can use Prefect's webhook functionality to trigger a flow on a Prefect server. Here's a general approach for both Prefect 2.x and 3.x: ### Prefect 2.x You can create automations by listening for specific events and responding to them via webhooks. Here's a useful guide from the documentation: 1. Define an event with a webhook:

{
  "event": "model-update",
  "resource": {
    "prefect.resource.id": "product.models.{{ body.model_id }}",
    "prefect.resource.name": "{{ body.friendly_name }}",
    "run_count": "{{ body.run_count }}"
  }
}

2. Use

curl

to send data to Prefect's API endpoint:

curl -X POST <https://api.prefect.cloud/hooks/34iV2SFke3mVa6y5Y-YUoA> -d "model_id=adhoc" -d "run_count=10" -d "friendly_name=test-user-input"

3. Create automations directly from the event feed to trigger downstream deployments. Further details: Automations Guide for Prefect 2.x and Concepts of Automations for Prefect 2.x. ### Prefect 3.x Similarly, for Prefect 3.x, you can create webhooks to trigger deployments: 1. Define a webhook to respond to specific events:

curl -X POST <https://api.prefect.cloud/hooks/34iV2SFke3mVa6y5Y-YUoA> -d "model_id=adhoc" -d "run_count=10" -d "friendly_name=test-user-input"

2. Use event triggers to automate deployment runs:

python
from prefect import flow, serve
from prefect.events import DeploymentEventTrigger

@flow(log_prints=True)
def upstream_flow():
    print("upstream flow")
    
@flow(log_prints=True)
def downstream_flow():
    print("downstream flow")

if __name__ == "__main__":
    upstream_deployment = upstream_flow.to_deployment(name="upstream_deployment")
    downstream_deployment = downstream_flow.to_deployment(
        name="downstream_deployment",
        triggers=[
            DeploymentEventTrigger(
                expect={"prefect.flow-run.Completed"},
                match_related={"prefect.resource.name": "upstream_deployment"},
            )
        ],
    )
    serve(upstream_deployment, downstream_deployment)

3. Start the serve process to listen for scheduled runs:

python event_driven_deployments.py

Further details: Webhook Triggers for Prefect 3.x and Custom Triggers for Prefect 3.x. Feel free to ask if you need more specific details!

@Marvin i am not using prefect cloud. only self hosted prefect server. how can i trigger a flow with api call

For self-hosted Prefect Server, you can trigger flows using API calls. The process differs slightly between Prefect 2.x and 3.x. ### Prefect 2.x To trigger a flow using an API call on a self-hosted Prefect 2.x server, you will typically use the

POST /flow_runs

endpoint provided by the Prefect API. 1. Create a flow run: Make a POST request to

http://<your-prefect-server-url>/api/flow_runs

with a JSON payload that specifies the

flow_id

and other relevant parameters. Example using `curl`:

curl -X POST http://<your-prefect-server-url>/api/flow_runs \
   -H "Content-Type: application/json" \
   -d '{
         "flow_id": "<your-flow-id>",
         "name": "my-flow-run"
       }'

2. Identify your flow ID: You can get the

flow_id

from the Prefect server UI or through another API call to

GET /flows

. ### Prefect 3.x In Prefect 3.x, you follow similar steps but with updates to the API endpoint structure: 1. Create a flow run: Make a POST request to

http://<your-prefect-server-url>/api/flow_runs

with a JSON payload, similar to Prefect 2.x but ensuring compatibility with the new API structure. Example using `curl`:

curl -X POST http://<your-prefect-server-url>/api/flow_runs \
   -H "Content-Type: application/json" \
   -d '{
         "flow_id": "<your-flow-id>",
         "name": "my-flow-run"
       }'

2. Identify your flow ID: The flow ID can be retrieved with an API call to

GET /flows

or by checking the Prefect server UI. Detailed instructions and API documentation can be found here: - Prefect 2.x Flow Concept - Prefect 3.x - Running Flows Feel free to ask if you need more specific examples or further steps!