Validate JSON data with schemas, types, required fields, formats, composition, and API contracts.
Lessons
See the complete study map from JSON basics to API contracts.
JSON Schema Syllabus is easiest to learn by reading the example, changing it, and observing the result.
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://example.com/schemas/lesson.json",
"title": "Lesson",
"type": "object",
"required": ["slug", "title"],
"properties": {
"slug": { "type": "string", "pattern": "^[a-z0-9-]+$" },
"title": { "type": "string", "minLength": 3, "maxLength": 80 },
"minutes": { "type": "integer", "minimum": 1 },
"level": { "type": "string", "enum": ["beginner", "advanced"] },
"tags": { "type": "array", "items": { "type": "string" }, "uniqueItems": true }
},
"additionalProperties": false
}Practice the JSON Schema Syllabus example in a small scratch file, then explain what changed and why.