It seems that tv4 is not actively developed anymore, nor does it support versions of JSON schema after draft-04. However this chai plugin will use tv4 as its backend for the forseeable future. If you want newer versions of the JSON-schema or more performance you could look at using ajv in conjunction with chai-json-schema-ajv
NOTES: JSON Schema validation is done by Tiny Validator tv4.
It seems that tv4 is not actively developed anymore, nor does it support versions of JSON schema after draft-04. However this chai plugin will use tv4 as its backend for the forseeable future. If you want newer versions of the JSON-schema or more performance you could look at using ajv in conjunction with chai-json-schema-ajv