add docs for RTKQ schema features

docs/rtk-query/api/createApi.mdx

@@ -221,6 +221,20 @@ export type QueryDefinition<
       updateCachedData, // available for query endpoints only
     }: QueryCacheLifecycleApi,
   ): Promise<void>
+
+  argSchema?: StandardSchemaV1<QueryArg>
+
+  /* only available with `query`, not `queryFn` */
+  rawResponseSchema?: StandardSchemaV1<BaseQueryResult<BaseQuery>>
+
+  responseSchema?: StandardSchemaV1<ResultType>
+
+  /* only available with `query`, not `queryFn` */
+  rawErrorResponseSchema?: StandardSchemaV1<BaseQueryError<BaseQuery>>
+
+  errorResponseSchema?: StandardSchemaV1<BaseQueryError<BaseQuery>>
+
+  metaSchema?: StandardSchemaV1<BaseQueryMeta<BaseQuery>>
 }
 ```
 
@@ -469,6 +483,26 @@ You can set this globally in `createApi`, but you can also override the default
 If you specify `track: false` when manually dispatching queries, RTK Query will not be able to automatically refetch for you.
 :::
 
+### `onSchemaFailure`
+
+[summary](docblock://query/createApi.ts?token=CreateApiOptions.onSchemaFailure)
+
+[examples](docblock://query/createApi.ts?token=CreateApiOptions.onSchemaFailure)
+
+:::note
+You can set this globally in `createApi`, but you can also override the default value and have more granular control by passing `onSchemaFailure` to each individual endpoint definition.
+:::
+
+### `skipSchemaValidation`
+
+[summary](docblock://query/createApi.ts?token=CreateApiOptions.skipSchemaValidation)
+
+[examples](docblock://query/createApi.ts?token=CreateApiOptions.skipSchemaValidation)
+
+:::note
+You can set this globally in `createApi`, but you can also override the default value and have more granular control by passing `skipSchemaValidation` to each individual endpoint definition.
+:::
+
 ## Endpoint Definition Parameters
 
 ### `query`
@@ -792,6 +826,64 @@ async function onCacheEntryAdded(
 ): Promise<void>
 ```
 
+### Schema Validation
+
+Endpoints can have schemas for runtime validation of various values. Any [Standard Schema](https://standardschema.dev/) compliant library can be used.
+
+:::warning
+
+Schema failures are treated as _fatal_, meaning that normal error handling such as tag invalidation will not be executed.
+
+:::
+
+#### `argSchema`
+
+_(optional)_
+
+[summary](docblock://query/endpointDefinitions.ts?token=CommonEndpointDefinition.argSchema)
+
+[examples](docblock://query/endpointDefinitions.ts?token=CommonEndpointDefinition.argSchema)
+
+#### `responseSchema`
+
+_(optional)_
+
+[summary](docblock://query/endpointDefinitions.ts?token=CommonEndpointDefinition.responseSchema)
+
+[examples](docblock://query/endpointDefinitions.ts?token=CommonEndpointDefinition.responseSchema)
+
+#### `rawResponseSchema`
+
+_(optional, not applicable with `queryFn`)_
+
+[summary](docblock://query/endpointDefinitions.ts?token=EndpointDefinitionWithQuery.rawResponseSchema)
+
+[examples](docblock://query/endpointDefinitions.ts?token=EndpointDefinitionWithQuery.rawResponseSchema)
+
+#### `errorResponseSchema`
+
+_(optional)_
+
+[summary](docblock://query/endpointDefinitions.ts?token=CommonEndpointDefinition.errorResponseSchema)
+
+[examples](docblock://query/endpointDefinitions.ts?token=CommonEndpointDefinition.errorResponseSchema)
+
+#### `rawErrorResponseSchema`
+
+_(optional, not applicable with `queryFn`)_
+
+[summary](docblock://query/endpointDefinitions.ts?token=EndpointDefinitionWithQuery.rawErrorResponseSchema)
+
+[examples](docblock://query/endpointDefinitions.ts?token=EndpointDefinitionWithQuery.rawErrorResponseSchema)
+
+#### `metaSchema`
+
+_(optional)_
+
+[summary](docblock://query/endpointDefinitions.ts?token=CommonEndpointDefinition.metaSchema)
+
+[examples](docblock://query/endpointDefinitions.ts?token=CommonEndpointDefinition.metaSchema)
+
 ## Return value
 
 See [the "created Api" API reference](./created-api/overview)

docs/rtk-query/usage-with-typescript.mdx

@@ -703,3 +703,135 @@ function AddPost() {
   )
 }
 ```
+
+## Schema Validation
+
+Endpoints can have schemas for runtime validation of various values. Any [Standard Schema](https://standardschema.dev/) compliant library can be used. See [API reference](./api/createApi.mdx#schema-validation) for full list of available schemas.
+
+When following the default approach of explicitly specifying type parameters for queries and mutations, the schemas will be required to match the types provided.
+
+```ts title="Explicitly typed endpoint" no-transpile
+import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react'
+import * as v from 'valibot'
+
+const postSchema = v.object({
+  id: v.number(),
+  name: v.string(),
+})
+type Post = v.InferOutput<typeof postSchema>
+
+const api = createApi({
+  baseQuery: fetchBaseQuery({ baseUrl: '/' }),
+  endpoints: (build) => ({
+    getPost: build.query<Post, { id: number }>({
+      query: ({ id }) => `/post/${id}`,
+      responseSchema: postSchema, // errors if type mismatch
+    }),
+  }),
+})
+```
+
+Schemas can also be used as a source of inference, meaning that the type parameters can be omitted.
+
+```ts title="Implicitly typed endpoint" no-transpile
+import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react'
+import * as v from 'valibot'
+
+const postSchema = v.object({
+  id: v.number(),
+  name: v.string(),
+})
+type Post = v.InferOutput<typeof postSchema>
+
+const api = createApi({
+  baseQuery: fetchBaseQuery({ baseUrl: '/' }),
+  endpoints: (build) => ({
+    getPost: build.query({
+      // infer arg from here
+      query: ({ id }: { id: number }) => `/post/${id}`,
+      // infer result from here
+      responseSchema: postSchema,
+    }),
+    getTransformedPost: build.query({
+      // infer arg from here
+      query: ({ id }: { id: number }) => `/post/${id}`,
+      // infer untransformed result from here
+      rawResponseSchema: postSchema,
+      // infer transformed result from here
+      transformResponse: (response) => ({
+        ...response,
+        published_at: new Date(response.published_at),
+      }),
+    }),
+  }),
+})
+```
+
+:::warning
+
+Schemas should _not_ perform any transformation that would change the type of the value.
+
+```ts title="Incorrect usage" no-transpile
+import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react'
+import * as v from 'valibot'
+import { titleCase } from 'lodash'
+
+const postSchema = v.object({
+  id: v.number(),
+  name: v.pipe(
+    v.string(),
+    v.transform(titleCase), // fine - string -> string
+  ),
+  published_at: v.pipe(
+    v.string(),
+    // highlight-next-line
+    v.transform((s) => new Date(s)), // not allowed!
+    v.date(),
+  ),
+})
+type Post = v.InferOutput<typeof postSchema>
+
+const api = createApi({
+  baseQuery: fetchBaseQuery({ baseUrl: '/' }),
+  endpoints: (build) => ({
+    getPost: build.query<Post, { id: number }>({
+      query: ({ id }) => `/post/${id}`,
+      responseSchema: postSchema,
+    }),
+  }),
+})
+```
+
+Instead, transformation should be done with `transformResponse` and `transformErrorResponse` (when using `query`) or inside `queryFn` (when using `queryFn`).
+
+```ts title="Correct usage" no-transpile
+import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react'
+import * as v from 'valibot'
+
+const postSchema = v.object({
+  id: v.number(),
+  name: v.string(),
+  published_at: v.string(),
+})
+type RawPost = v.InferOutput<typeof postSchema>
+type Post = Omit<RawPost, 'published_at'> & { published_at: Date }
+
+const api = createApi({
+  baseQuery: fetchBaseQuery({ baseUrl: '/' }),
+  endpoints: (build) => ({
+    getPost: build.query<Post, { id: number }>({
+      query: ({ id }) => `/post/${id}`,
+      // use rawResponseSchema to validate *before* transformation
+      rawResponseSchema: postSchema,
+      // highlight-start
+      transformResponse: (response) => ({
+        ...response,
+        published_at: new Date(response.published_at),
+      }),
+      // highlight-end
+    }),
+  }),
+})
+```
+
+:::

docs/rtk-query/usage/infinite-queries.mdx

@@ -531,3 +531,59 @@ const projectsApi = createApi({
   }),
 })
 ```
+
+## Runtime Validation using Schemas
+
+Endpoints can use any [Standard Schema](https://standardschema.dev/) compliant library for runtime validation of various values. See [API reference](../api/createApi.mdx#schema-validation) for full list of available schemas.
+
+Most commonly, you'll want to use `responseSchema` to validate the response from the server (or `rawResponseSchema` when using `transformResponse`).
+
+```ts title="Using responseSchema" no-transpile
+import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react'
+import * as v from 'valibot'
+
+const pokemonSchema = v.object({
+  id: v.number(),
+  name: v.string(),
+})
+type Pokemon = v.InferOutput<typeof pokemonSchema>
+const transformedPokemonSchema = v.object({
+  ...pokemonSchema.entries,
+  id: v.string(),
+})
+type TransformedPokemon = v.InferOutput<typeof transformedPokemonSchema>
+
+const api = createApi({
+  baseQuery: fetchBaseQuery({ baseUrl: 'https://example.com/pokemon' }),
+  endpoints: (build) => ({
+    getInfinitePokemon: build.infiniteQuery<Pokemon[], string, number>({
+      query: ({ queryArg, pageParam }) => `type/${queryArg}?page=${pageParam}`,
+      // argSchema for infinite queries must have both queryArg and pageParam
+      argSchema: v.object({
+        queryArg: v.string(),
+        pageParam: v.number(),
+      }),
+      responseSchema: v.array(pokemonSchema),
+    }),
+    getTransformedPokemon: build.infiniteQuery<
+      TransformedPokemon[],
+      string,
+      number
+    >({
+      query: ({ queryArg, pageParam }) => `type/${queryArg}?page=${pageParam}`,
+      argSchema: v.object({
+        queryArg: v.string(),
+        pageParam: v.number(),
+      }),
+      rawResponseSchema: v.array(pokemonSchema),
+      transformResponse: (response) =>
+        response.map((pokemon) => ({
+          ...pokemon,
+          id: String(pokemon.id),
+        })),
+      // responseSchema can still be provided, to validate the transformed response
+      responseSchema: v.array(transformedPokemonSchema),
+    }),
+  }),
+})
+```

docs/rtk-query/usage/mutations.mdx

@@ -326,3 +326,60 @@ export const {
   allow="geolocation; microphone; camera; midi; vr; accelerometer; gyroscope; payment; ambient-light-sensor; encrypted-media; usb"
   sandbox="allow-modals allow-forms allow-popups allow-scripts allow-same-origin"
 ></iframe>
+
+## Runtime Validation using Schemas
+
+Endpoints can use any [Standard Schema](https://standardschema.dev/) compliant library for runtime validation of various values. See [API reference](../api/createApi.mdx#schema-validation) for full list of available schemas.
+
+Most commonly, you'll want to use `responseSchema` to validate the response from the server (or `rawResponseSchema` when using `transformResponse`).
+
+```ts title="Using responseSchema" no-transpile
+import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react'
+import * as v from 'valibot'
+
+const postSchema = v.object({
+  id: v.number(),
+  name: v.string(),
+  published_at: v.string(),
+})
+type Post = v.InferOutput<typeof postSchema>
+const transformedPost = v.object({
+  ...postSchema.entries,
+  published_at: v.date(),
+})
+type TransformedPost = v.InferOutput<typeof transformedPost>
+
+const api = createApi({
+  baseQuery: fetchBaseQuery({ baseUrl: '/' }),
+  endpoints: (build) => ({
+    updatePost: build.mutation<Post, Partial<Post>>({
+      query(data) {
+        const { id, ...body } = data
+        return {
+          url: `post/${id}`,
+          method: 'PUT',
+          body,
+        }
+      },
+      responseSchema: postSchema,
+    }),
+    updatePostWithTransform: build.mutation<TransformedPost, Partial<Post>>({
+      query(data) {
+        const { id, ...body } = data
+        return {
+          url: `post/${id}`,
+          method: 'PUT',
+          body,
+        }
+      },
+      rawResponseSchema: postSchema,
+      transformResponse: (response) => ({
+        ...response,
+        published_at: new Date(response.published_at),
+      }),
+      // responseSchema can still be provided, to validate the transformed response
+      responseSchema: transformedPost,
+    }),
+  }),
+})
+```