Standard Schema

Every schema implements Standard Schema, so libraries that support it accept typed schemas directly, with no adapter. The Standard Schema site has the spec and a list of the libraries that support it.

This Hono route receives a Sanity webhook and validates its body with @hono/standard-validator:

import {sValidator} from '@hono/standard-validator'
import * as s from '@sanity-labs/typed-schema'
import {Hono} from 'hono'

const Recipe = s.document({
  _type: s.literal('recipe'),
  title: s.string(),
  servings: s.optional(s.number()),
})

const app = new Hono()

app.post(
  '/webhooks/recipe-published',
  sValidator('json', Recipe, (result, c) => {
    if (!result.success) {
      // for a body with title: 42:
      // Invalid input (1 issue):
      //   title: Expected a string
      return c.text(s.formatIssues(result.error), 400)
    }
  }),
  c => {
    const recipe = c.req.valid('json')
        
const recipe: {
    _type: "recipe";
    _id?: string | undefined;
    _createdAt?: string | undefined;
    _updatedAt?: string | undefined;
    _rev?: string | undefined;
    title: string;
    servings?: number | undefined;
}
    return c.text(`Received ${recipe.title}`)
  },
)

How typed schemas implement it

• validate runs parse and returns synchronously. In code that only uses typed schemas, call parse or parseOrThrow instead: they return the same value, and their issues also have a code.
• The input type is the value as stored (Infer). The output type is what parse returns (Parsed), which adds a non-enumerable $refSchema key to reference values; see Loading documents and references.
• In issue paths, an item in an array of objects appears as {key: 0, _key: 'a1'}. A library that follows the spec finds the item by its position in key; code that knows about Sanity can use the _key.
• formatIssues and formatPath accept Standard Schema issues and paths from any library, and write them the way ParseError.message does.
• The ~standard property is non-enumerable, like output, so JSON.stringify and Object.keys skip it and schemas stay plain data.
• The package exports the StandardSchemaV1 type, so code that accepts a schema from any library does not need @standard-schema/spec.