fix(openai,core): Make OpenAI withStructuredOutput typing compatible with other models

langchain-core/src/language_models/base.ts

@@ -262,6 +262,8 @@ export type StructuredOutputMethodOptions<IncludeRaw extends boolean = false> =
     name?: string;
     method?: "functionCalling" | "jsonMode" | "jsonSchema" | string;
     includeRaw?: IncludeRaw;
+    /** Whether to use strict mode. Currently only supported by OpenAI models. */
+    strict?: boolean;
   };
 
 /** @deprecated Use StructuredOutputMethodOptions instead */
@@ -514,7 +516,6 @@ export abstract class BaseLanguageModel<
   withStructuredOutput?<
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     RunOutput extends Record<string, any> = Record<string, any>
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
   >(
     schema:
       | z.ZodType<RunOutput>

langchain-core/src/language_models/chat_models.ts

@@ -802,7 +802,6 @@ export abstract class BaseChatModel<
   withStructuredOutput<
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     RunOutput extends Record<string, any> = Record<string, any>
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
   >(
     outputSchema:
       | z.ZodType<RunOutput>
@@ -845,6 +844,11 @@ export abstract class BaseChatModel<
         `Chat model must implement ".bindTools()" to use withStructuredOutput.`
       );
     }
+    if (config?.strict) {
+      throw new Error(
+        `"strict" mode is not supported for this model by default.`
+      );
+    }
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     const schema: z.ZodType<RunOutput> | Record<string, any> = outputSchema;
     const name = config?.name;

libs/langchain-community/src/chat_models/tests/chatbedrock.int.test.ts

@@ -9,6 +9,7 @@ import { ChatPromptTemplate } from "@langchain/core/prompts";
 import { concat } from "@langchain/core/utils/stream";
 import { z } from "zod";
 import { zodToJsonSchema } from "zod-to-json-schema";
+import { ChatOpenAI } from "@langchain/openai";
 import { BedrockChat as BedrockChatWeb } from "../bedrock/web.js";
 import { TavilySearchResults } from "../../tools/tavily_search.js";
 
@@ -531,3 +532,31 @@ test("Streaming tool calls with Anthropic", async () => {
   expect(finalChunk?.tool_calls?.[0].name).toBe("weather_tool");
   expect(finalChunk?.tool_calls?.[0].args?.city).toBeDefined();
 });
+
+test("withStructuredOutput result should be compatible with OpenAI typing", async () => {
+  const testSchema = z.object({
+    thinking_process: z
+      .string()
+      .describe(
+        "Think before generating variants and put your reasoning here."
+      ),
+    variants: z
+      .array(
+        z.object({
+          name: z.string(),
+          value: z.string(),
+        })
+      )
+      .describe("Variants of the input"),
+  });
+
+  const _prepareClient = () => {
+    if (Math.random() > 0.5) {
+      return new ChatOpenAI();
+    }
+
+    return new BedrockChatWeb();
+  };
+
+  _prepareClient().withStructuredOutput(testSchema);
+});

libs/langchain-openai/src/chat_models.ts

@@ -343,6 +343,7 @@ function _convertChatOpenAIToolTypeToOpenAITool(
   return _convertToOpenAITool(tool, fields);
 }
 
+// TODO: Use the base structured output options param in next breaking release.
 export interface ChatOpenAIStructuredOutputMethodOptions<
   IncludeRaw extends boolean
 > extends StructuredOutputMethodOptions<IncludeRaw> {
@@ -1940,7 +1941,6 @@ export class ChatOpenAI<
     RunOutput extends Record<string, any> = Record<string, any>
   >(
     outputSchema:
-      | StructuredOutputMethodParams<RunOutput, false>
       | z.ZodType<RunOutput>
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
       | Record<string, any>,
@@ -1952,7 +1952,6 @@ export class ChatOpenAI<
     RunOutput extends Record<string, any> = Record<string, any>
   >(
     outputSchema:
-      | StructuredOutputMethodParams<RunOutput, true>
       | z.ZodType<RunOutput>
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
       | Record<string, any>,
@@ -1964,7 +1963,6 @@ export class ChatOpenAI<
     RunOutput extends Record<string, any> = Record<string, any>
   >(
     outputSchema:
-      | StructuredOutputMethodParams<RunOutput, boolean>
       | z.ZodType<RunOutput>
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
       | Record<string, any>,