@ark/json-schema

What is it?

@ark/json-schema is a package that allows converting from a JSON Schema schema to an ArkType Type. For example:

import { jsonSchemaToType } from "@ark/json-schema"

const T = jsonSchemaToType({ type: "string", minLength: 5, maxLength: 10 })

is equivalent to:

import { type } from "arktype"

const T = type("5<=string<=10")

This enables easy adoption of ArkType for people who currently have JSON Schema based runtime validation in their codebase.

If you want to convert your existing ArkType Types to JSON Schema, you don't need this library.

Instead, use the built-in toJsonSchema() method that exists on every Type, e.g.:

import { type } from "arktype"

// { type: "string", minLength: 5, maxLength: 10 }
const schema = type("5<=string<=10").toJsonSchema()

Extra Type Safety

If you wish to ensure that your JSON Schema schemas are valid, you can do this too! Simply import the relevant Schema type from @ark/json-schema like so:

import type { JsonSchema } from "arktype"

const integerSchema: JsonSchema.Numeric = {
    type: "integer",
    multipleOf: "3" // errors stating that 'multipleOf' must be a number
}

Note that for string schemas exclusively, you must import the schema type from @ark/json-schema instead of arktype. This is because @ark/json-schema doesn't yet support the format keyword whilst arktype does.

import type { StringSchema } from "@ark/json-schema"
const stringSchema: StringSchema = {
    type: "string",
    minLength: "3" // errors stating that 'minLength' must be a number
}

Limitations

• No dependencies support
• No if/else/then support
• multipleOf only supports integers