make streamUI() from @ai-sdk/rsc accept zod v4

Author: gr2m

.changeset/eight-months-sip.md

@@ -10,3 +10,5 @@ All these methods now accept both a zod v4 and zod v3 schemas for validation:
 - `generateObject()`
 - `streamObject()`
 - `generateText()`
+- `experimental_useObject()` from `@ai-sdk/react`
+- `streamUI()` from `@ai-sdk/rsc`

packages/provider-utils/src/parse-json.ts

@@ -4,9 +4,11 @@ import {
   TypeValidationError,
 } from '@ai-sdk/provider';
 import { secureJsonParse } from './secure-json-parse';
-import { ZodSchema } from 'zod';
+import * as z3 from 'zod/v3';
+import * as z4 from 'zod/v4/core';
 import { safeValidateTypes, validateTypes } from './validate-types';
 import { Validator } from './validator';
+import { InferSchema } from './schema';
 
 /**
  * Parses a JSON string into an unknown object.
@@ -26,17 +28,17 @@ export async function parseJSON(options: {
  * @param {Validator<T>} schema - The schema to use for parsing the JSON.
  * @returns {Promise<T>} - The parsed object.
  */
-export async function parseJSON<T>(options: {
+export async function parseJSON<SCHEMA extends z4.$ZodType | z3.Schema | Validator, VALUE = InferSchema<SCHEMA>>(options: {
   text: string;
-  schema: ZodSchema<T> | Validator<T>;
-}): Promise<T>;
-export async function parseJSON<T>({
+  schema: SCHEMA;
+}): Promise<VALUE>;
+export async function parseJSON<SCHEMA extends z4.$ZodType | z3.Schema | Validator, VALUE = InferSchema<SCHEMA>>({
   text,
   schema,
 }: {
   text: string;
-  schema?: ZodSchema<T> | Validator<T>;
-}): Promise<T> {
+  schema?: SCHEMA;
+}): Promise<VALUE> {
   try {
     const value = secureJsonParse(text);
 
@@ -83,22 +85,22 @@ export async function safeParseJSON(options: {
  * @param {Validator<T>} schema - The schema to use for parsing the JSON.
  * @returns An object with either a `success` flag and the parsed and typed data, or a `success` flag and an error object.
  */
-export async function safeParseJSON<T>(options: {
+export async function safeParseJSON<SCHEMA extends z4.$ZodType | z3.Schema | Validator, VALUE = InferSchema<SCHEMA>>(options: {
   text: string;
-  schema: ZodSchema<T> | Validator<T>;
-}): Promise<ParseResult<T>>;
-export async function safeParseJSON<T>({
+  schema: SCHEMA;
+}): Promise<ParseResult<VALUE>>;
+export async function safeParseJSON<SCHEMA extends z4.$ZodType | z3.Schema | Validator, VALUE = InferSchema<SCHEMA>>({
   text,
   schema,
 }: {
   text: string;
-  schema?: ZodSchema<T> | Validator<T>;
-}): Promise<ParseResult<T>> {
+  schema?: SCHEMA;
+}): Promise<ParseResult<VALUE>> {
   try {
     const value = secureJsonParse(text);
 
     if (schema == null) {
-      return { success: true, value: value as T, rawValue: value };
+      return { success: true, value: value as VALUE, rawValue: value };
     }
 
     return await safeValidateTypes({ value, schema });

packages/rsc/src/stream-ui/stream-ui.tsx

@@ -1,7 +1,8 @@
 import { LanguageModelV2, LanguageModelV2CallWarning } from '@ai-sdk/provider';
-import { safeParseJSON } from '@ai-sdk/provider-utils';
+import { InferSchema, safeParseJSON } from '@ai-sdk/provider-utils';
 import { ReactNode } from 'react';
-import { z } from 'zod';
+import * as z3 from 'zod/v3';
+import * as z4 from 'zod/v4/core';
 import {
   CallWarning,
   FinishReason,
@@ -35,16 +36,12 @@ type Renderer<T extends Array<any>> = (
   | Generator<Streamable, Streamable, void>
   | AsyncGenerator<Streamable, Streamable, void>;
 
-type RenderTool<PARAMETERS extends z.Schema | Schema = any> = {
+type RenderTool<PARAMETERS_SCHEMA extends z4.$ZodType | z3.Schema | Schema = any> = {
   description?: string;
-  parameters: PARAMETERS;
+  parameters: PARAMETERS_SCHEMA;
   generate?: Renderer<
     [
-      PARAMETERS extends z.Schema
-        ? z.infer<PARAMETERS>
-        : PARAMETERS extends Schema<infer T>
-          ? T
-          : never,
+      InferSchema<PARAMETERS_SCHEMA>,
       {
         toolName: string;
         toolCallId: string;
@@ -86,7 +83,7 @@ const defaultTextRenderer: RenderText = ({ content }: { content: string }) =>
  * `streamUI` is a helper function to create a streamable UI from LLMs.
  */
 export async function streamUI<
-  TOOLS extends { [name: string]: z.Schema | Schema } = {},
+  TOOLS extends { [name: string]: z4.$ZodType | z3.Schema | Schema } = {},
 >({
   model,
   tools,