Generate and validate JSON Schema locally on your Mac

Why generate JSON Schema locally?

Schema work often starts from real payloads: webhook bodies, internal API responses, model outputs or customer-shaped data. A local JSON Schema generator keeps those examples on your Mac.

That matters when the schema describes private contracts or when the sample document contains identifiers, emails, tokens or business data.

Infer a schema from sample documents

Paste sample JSON and generate a readable JSON Schema for contracts, tests, documentation, structured AI outputs or validation rules.

The tool recognizes optional properties, nullable fields and repeated vocabularies instead of relying on the first object alone.

Validate JSON with per-path errors

Switch to validation mode to compare a JSON document against a schema. CodeSwissKnife reports one error per path and highlights errors directly in the document, which makes failures easier to fix than a single generic parser message.

Use it before shipping fixtures, API examples, tool schemas or model output contracts.

Merge every array element during inference

Real arrays rarely have one perfect representative element. The inferrer merges every element, so later records can still contribute properties, enum-like vocabularies and nullability to the final schema.

Know which schema keywords are not evaluated

Validators should be explicit about unsupported behavior. When CodeSwissKnife sees a keyword it does not evaluate, it names it instead of silently pretending the whole schema was checked.