Metaschema

jsonschema metaschema [schemas-or-directories...]
  [--http/-h] [--verbose/-v] [--debug/-g] [--extension/-e <extension>]
  [--header/-H "<name>: <value>"]
  [--resolve/-r <schemas-or-directories> ...]
  [--ignore/-i <schemas-or-directories>] [--trace/-t]
  [--default-dialect/-d <uri>] [--json/-j] [--format-assertion/-F]

Ensure that a schema or a set of schemas are considered valid with regards to their metaschemas. The --json/-j option outputs the evaluation result using the JSON Schema Basic standard format.

The --resolve/-r option is crucial to import custom meta-schemas into the resolution context, otherwise the validator won't know where to look for them.

To help scripts distinguish validation errors, these are reported using exit code 2.

Examples

For example, consider this fictitious JSON Schema that follows the Draft 4 dialect but sets the type property to an invalid value:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": 1
}

Running the metaschema command on it will surface an error:

$ jsonschema metaschema schema.json
error: The target document is expected to be one of the given values
    at instance location "/type"
    at evaluate path "/properties/type/anyOf/0/$ref/enum"
error: Mark the current position of the evaluation process for future jumps
    at instance location "/type"
    at evaluate path "/properties/type/anyOf/0/$ref"
error: The target document is expected to be of the given type
    at instance location "/type"
    at evaluate path "/properties/type/anyOf/1/type"
error: The target is expected to match at least one of the given assertions
    at instance location "/type"
    at evaluate path "/properties/type/anyOf"
error: The target is expected to match all of the given assertions
    at instance location ""
    at evaluate path "/properties"

Validate the metaschema of JSON Schemas in-place

jsonschema metaschema path/to/my/schema_1.json path/to/my/schema_2.json

Validate a JSON Schema with a custom meta-schema

jsonschema validate path/to/my/schema.json --resolve path/to/custom-meta-schema.json

Validate the metaschema of every .json file in a given directory (recursively)

jsonschema metaschema path/to/schemas/

Validate the metaschema of every .json file in the current directory (recursively)

jsonschema metaschema

Validate the metaschema of every .json file in a given directory while ignoring another

jsonschema metaschema path/to/schemas/ --ignore path/to/schemas/nested

Validate the metaschema of every .schema.json file in the current directory (recursively)

jsonschema metaschema --extension .schema.json

Validate the metaschema of a JSON Schema with trace information

jsonschema metaschema path/to/my/schema.json --trace

Validate the metaschema of a JSON Schema forcing every format to assert

The --format-assertion/-F option forces every format keyword in the metaschema to behave as an assertion. For 2020-12 schemas, this turns checks like $id being a valid URI reference into hard failures rather than just annotations.

jsonschema metaschema path/to/my/schema.json --format-assertion

Validate the metaschema of a JSON Schema and print the result as JSON

jsonschema metaschema path/to/my/schema.json --json

Validate the metaschema of a JSON Schema with a custom HTTP header

jsonschema metaschema path/to/my/schema.json \
  --http --header "Authorization: Bearer $REGISTRY_TOKEN"