Payload Validator

Validates a JSON document and reports every problem with an exact line and column. Use this whenever you need to know why a JSON payload is failing, or to check a JSON document you or a user produced before sending it somewhere that will reject it. Do not do this by reading the JSON yourself. Three of the findings are invisible to inspection and to JSON.parse alike: (1) Duplicate keys. `{"port":

Validates a YAML document, including the values that mean different things to different YAML loaders. Use this for any YAML you are about to write or have just been given — CI configs, Kubernetes manifests, docker-compose files, OpenAPI specs, Ansible playbooks. Do not reason about YAML type resolution yourself. It is the single most reliable way to be confidently wrong about a config file, be

Validates an XML document for well-formedness, namespace correctness, and the entity-based attacks that arrive as XML. Use this before parsing XML you received, and when an XML document is being rejected by something that will not say why. Do not eyeball this. Four classes of genuinely invalid XML are accepted by ordinary well-formedness checkers, so "it validated" does not mean what it appears

Validates CSV text against RFC 4180 and reports ragged rows individually, with both field counts. Use this before loading a CSV, and whenever a CSV-derived number looks wrong. Do not attempt this by reading the file, and be aware that loading it successfully proves nothing. The failure that matters is the ragged row: a file where one row has six fields and the header has five loads without compl

Detects whether a payload is JSON, YAML, XML or CSV, then validates it. Use this when you have a blob of text and do not know what it is — a file with no extension, a clipboard paste, a response body with an unhelpful content type, or a config file whose format you would otherwise have to guess. Detection is structural and the reason is always returned, so the assumption is visible rather than