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Input validation

RunPod's validator utility ensures robust execution of serverless workers by validating input data against a defined schema.

To use it, import the following to your Python file:

from runpod.serverless.utils.rp_validator import validate

The validate function takes two arguments:

  • the input data
  • the schema to validate against

Schema Definition​

Define your schema as a nested dictionary with these possible rules for each input:

  • required (default: False): Marks the type as required.
  • default (default: None): Default value if input is not provided.
  • type (required): Expected input type.
  • constraints (optional): for example, a lambda function returning true or false.

Example Usage​

import runpod
from runpod.serverless.utils.rp_validator import validate

schema = {
    "text": {
        "type": str,
        "required": True,
    },
    "max_length": {
        "type": int,
        "required": False,
        "default": 100,
        "constraints": lambda x: x > 0,
    }
}

def handler(event):
    try:
        validated_input = validate(event["input"], schema)
        if 'errors' in validated_input:
            return {"error": validated_input['errors']}
        
        text = validated_input['validated_input']['text']
        max_length = validated_input['validated_input']['max_length']
        
        result = text[:max_length]
        return {"output": result}
    except Exception as e:
        return {"error": str(e)}

runpod.serverless.start({"handler": handler})

Testing​

Save as your_handler.py and test using:

python your_handler.py

Or with inline input:

python your_handler.py --test_input '{"input": {"text": "Hello, world!", "max_length": 5}}'

This approach allows early detection of input errors, preventing issues from unexpected or malformed inputs.