What you describe is called a JSON schema.

For example the JSON schema for the following JSON:

{
        "first" : "Fred",
        "last" : "Flintstone"
}

Would be something like this:

{
  "type": "object",
  "properties": {
    "first": { "type": "string" },
    "last": { "type": "string" },
  }
}

You can then use the jsonschema package for validation:

from jsonschema import validate


validate(
    instance=json_to_validate, schema=json_schema,
)