schema

schema is a function that takes a JSON Schema definition, and validates that an object looked up via JSON Path matches that schema. If the object does not exist, the function will trigger a rule violation

How do I use this function?

This function is configured by the following functionOptions

NAME	TYPE	REQUIRED?	DESCRIPTION
schema	`JSON Schema`	yes	The schema you want to evaluate
forceValidationOnCurrentNode	`boolean`	no	Validate the current node directly instead of looking for a field (default: false, auto-enabled for root validation with no field)

Important Notes

When validating non-OpenAPI documents, use the --skip-check flag with the vacuum CLI
When given is "$" (root) and no field is specified, the function automatically validates the entire document against the schema (equivalent to forceValidationOnCurrentNode: true)
This automatic behavior ensures consistency with Spectral when validating entire documents

Example ruleset configuration

openapi-tags:
  description: Global tags should exist, and be an array
  type: validation
  recommended: false
  given: "$"
  then:
    field: "tags"
    function: "schema"
    functionOptions:
      schema:
        type: "array"
        items:
          type: "object"
          minItems: 1
        uniqueItems: true

Example for validating non-OpenAPI documents

When validating entire non-OpenAPI YAML/JSON documents (e.g., configuration files), the schema function will automatically validate the root node when no field is specified:

# Rule to ensure a configuration file only contains allowed properties
config-validation:
  description: Ensure only valid properties in config file
  severity: error
  given: "$"  # Match the root
  then:
    # No field specified - validates entire document
    function: "schema"
    functionOptions:
      schema:
        type: object
        properties:
          consumers:
            type: array
            items:
              type: object
              properties:
                name:
                  type: string
                id:
                  type: string
              required: [name, id]
        additionalProperties: false  # Reject any properties not defined above

To lint a non-OpenAPI document with this rule:

vacuum lint config.yaml -r rules.yaml --skip-check

View Spectral Equivalent

View Function Source