JSON Schema Builder

System prompt (SKILL.md)

---
name: json-schema-builder
description: Build a JSON Schema visually - add typed properties and nested objects, and copy the generated schema.
metadata:
  tags:
    - artifact-import
    - dev-tools
  source_url: https://tools.simonwillison.net/json-schema-builder
  github_repo_url: https://github.com/simonw/tools
---

# JSON Schema Builder

An imported Claude artifact. Give the schema a title and description, then add
properties one at a time - including nested objects - and watch the JSON Schema
build up live beside the form, with a copy button when you are done.

Useful when you need a schema by hand rather than by inference: tool and
function-calling definitions, structured-output contracts, config validation.

The current schema is kept in the URL fragment, so the link restores your work.
Everything runs client-side - no upload, no model call, nothing metered.

Release files (files)