Verify Schema Step Demo

Verify Schema Step Demo#

This notebook walks through a simple example of using the verify-schema step in serving functions, by first downloading the step from the hub and inpecting it, then including the step in the function in two different approaches.

Get the step from the hub#

import mlrun

hub_step = mlrun.get_hub_step("hub://verify_schema")

Now the file has been downloaded to our current working directory (provide local_path paramater to change this default destination), and we can edit it directly.

We can also inspect the hub_stpe object:

hub_step.to_dict()

{'filename': 'verify_schema.py',
 'example': 'verify_schema.ipynb',
 'local_path': PosixPath('/User'),
 'url': 'hub://verify_schema',
 'class_name': 'VerifySchema',
 'name': 'verify_schema',
 'version': '1.0.0',
 'categories': ['data-preparation', 'model-serving', 'utilities'],
 'description': 'Verifies the event is aligned with the provided schema'}

Use custom step in a function#

When we are done with editing the step code, we are ready to use it in a function, as any other custom step:

project = mlrun.get_or_create_project("verify-schema-step-demo",'./verify-schema-step-demo')

> 2025-12-31 09:00:01,987 [info] Project loaded successfully: {"project_name":"verify-schema-step-demo"}

fn = project.set_function(hub_step.get_src_file_path(), name="serving-fn", kind="serving", image = "mlrun/mlrun" )
graph = fn.set_topology("flow", engine="async")
schema = ["id", "height", "weight"]
graph.to(class_name="VerifySchema", name="verify", schema=schema)

project.deploy_function(fn)

serving_fn = project.get_function("serving-fn")
event = {
    "id": "3425",
    "height": 157,
    "weight": 58
}
serving_fn.invoke("/", body=event)

{'id': '3425', 'height': 157, 'weight': 58}

Or try to raise an error:

event = {
    "id": "3425",
    "height": 157
}
serving_fn.invoke("/", body=event)

Add step directly from the hub#

In case you don’t need to make any changes to the step code, you can add the step directly from the hub:

graph.add_step(class_name="hub://verify_schema", name="verify-2", schema=schema).respond()

project.deploy_function(fn)

event = {
    "id": "3425",
    "height": 157,
    "weight": 58
}
serving_fn.invoke("/", body=event)
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