fix(openai): Prevent extra constructor params from being serialized, …

…add script (#7669)

libs/langchain-openai/package.json

@@ -41,7 +41,7 @@
     "zod-to-json-schema": "^3.22.3"
   },
   "peerDependencies": {
-    "@langchain/core": ">=0.3.29 <0.4.0"
+    "@langchain/core": ">=0.3.39 <0.4.0"
   },
   "devDependencies": {
     "@azure/identity": "^4.2.1",

libs/langchain-openai/src/azure/chat_models.ts

@@ -473,6 +473,21 @@ export class AzureChatOpenAI extends ChatOpenAI {
     };
   }
 
+  get lc_serializable_keys(): string[] {
+    return [
+      ...super.lc_serializable_keys,
+      "azureOpenAIApiKey",
+      "azureOpenAIApiVersion",
+      "azureOpenAIBasePath",
+      "azureOpenAIEndpoint",
+      "azureOpenAIApiInstanceName",
+      "azureOpenAIApiDeploymentName",
+      "deploymentName",
+      "openAIApiKey",
+      "openAIApiVersion",
+    ];
+  }
+
   constructor(
     fields?: Partial<OpenAIChatInput> &
       Partial<AzureOpenAIInput> & {

libs/langchain-openai/src/chat_models.ts

@@ -905,6 +905,45 @@ export class ChatOpenAI<
     };
   }
 
+  get lc_serializable_keys(): string[] {
+    return [
+      "configuration",
+      "logprobs",
+      "topLogprobs",
+      "prefixMessages",
+      "supportsStrictToolCalling",
+      "modalities",
+      "audio",
+      "reasoningEffort",
+      "temperature",
+      "maxTokens",
+      "topP",
+      "frequencyPenalty",
+      "presencePenalty",
+      "n",
+      "logitBias",
+      "user",
+      "streaming",
+      "streamUsage",
+      "modelName",
+      "model",
+      "modelKwargs",
+      "stop",
+      "stopSequences",
+      "timeout",
+      "openAIApiKey",
+      "apiKey",
+      "cache",
+      "maxConcurrency",
+      "maxRetries",
+      "verbose",
+      "callbacks",
+      "tags",
+      "metadata",
+      "disableStreaming",
+    ];
+  }
+
   temperature?: number;
 
   topP?: number;

libs/langchain-openai/src/tests/azure/chat_models.test.ts

@@ -23,6 +23,20 @@ test("Test Azure OpenAI serialization from azure endpoint", async () => {
   );
 });
 
+test("Test Azure OpenAI serialization does not pass along extra params", async () => {
+  const chat = new AzureChatOpenAI({
+    azureOpenAIEndpoint: "https://foobar.openai.azure.com/",
+    azureOpenAIApiDeploymentName: "gpt-4o",
+    azureOpenAIApiVersion: "2024-08-01-preview",
+    azureOpenAIApiKey: "foo",
+    extraParam: "extra",
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  } as any);
+  expect(JSON.stringify(chat)).toEqual(
+    `{"lc":1,"type":"constructor","id":["langchain","chat_models","azure_openai","AzureChatOpenAI"],"kwargs":{"azure_endpoint":"https://foobar.openai.azure.com/","deployment_name":"gpt-4o","openai_api_version":"2024-08-01-preview","azure_open_ai_api_key":{"lc":1,"type":"secret","id":["AZURE_OPENAI_API_KEY"]}}}`
+  );
+});
+
 test("Test Azure OpenAI serialization from base path", async () => {
   const chat = new AzureChatOpenAI({
     azureOpenAIBasePath:

libs/langchain-openai/src/tests/chat_models.test.ts

@@ -259,3 +259,15 @@ describe("strict tool calling", () => {
     }
   });
 });
+
+test("Test OpenAI serialization doesn't pass along extra params", async () => {
+  const chat = new ChatOpenAI({
+    apiKey: "test-key",
+    model: "o3-mini",
+    somethingUnexpected: true,
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  } as any);
+  expect(JSON.stringify(chat)).toEqual(
+    `{"lc":1,"type":"constructor","id":["langchain","chat_models","openai","ChatOpenAI"],"kwargs":{"openai_api_key":{"lc":1,"type":"secret","id":["OPENAI_API_KEY"]},"model":"o3-mini"}}`
+  );
+});

libs/langchain-scripts/bin/extract_serializable_fields.js

@@ -0,0 +1,2 @@
+#!/usr/bin/env node
+import "../dist/extract_serializable_fields.js";

libs/langchain-scripts/package.json

@@ -14,6 +14,7 @@
   },
   "homepage": "https://github.com/langchain-ai/langchainjs/tree/main/libs/langchain-scripts/",
   "bin": {
+    "extract_serializable_fields": "bin/extract_serializable_fields.js",
     "filter_spam_comment": "bin/filter_spam_comment.js",
     "lc_build": "bin/build.js",
     "notebook_validate": "bin/validate_notebook.js"

libs/langchain-scripts/src/extract_serializable_fields.ts

@@ -0,0 +1,81 @@
+import ts from "typescript";
+import * as path from "path";
+
+function extractConstructorParams(
+  sourceFile: string,
+  className: string
+): { type: string; fields: string[] } | null {
+  const absolutePath = path.resolve(sourceFile);
+  const program = ts.createProgram([absolutePath], {
+    target: ts.ScriptTarget.ES2015,
+    module: ts.ModuleKind.CommonJS,
+  });
+  const source = program.getSourceFile(absolutePath);
+  const typeChecker = program.getTypeChecker();
+
+  if (!source) {
+    console.error(`Could not find source file: ${absolutePath}`);
+    return null;
+  }
+
+  let result: { type: string; fields: string[] } | null = null;
+
+  function visit(node: ts.Node) {
+    if (ts.isClassDeclaration(node) && node.name?.text === className) {
+      node.members.forEach((member) => {
+        if (
+          ts.isConstructorDeclaration(member) &&
+          member.parameters.length > 0
+        ) {
+          const firstParam = member.parameters[0];
+          const type = typeChecker.getTypeAtLocation(firstParam);
+          const typeString = typeChecker.typeToString(type);
+
+          // Get properties of the type
+          const fields: string[] = [];
+          type.getProperties().forEach((prop) => {
+            // Get the type of the property
+            const propType = typeChecker.getTypeOfSymbolAtLocation(
+              prop,
+              firstParam
+            );
+            // Only include non-function properties that don't start with __
+            if (
+              !prop.getName().startsWith("__") &&
+              prop.getName() !== "callbackManager" &&
+              !(propType.getCallSignatures().length > 0)
+            ) {
+              fields.push(prop.getName());
+            }
+          });
+
+          result = {
+            type: typeString,
+            fields,
+          };
+        }
+      });
+    }
+    ts.forEachChild(node, visit);
+  }
+
+  visit(source);
+  return result;
+}
+const filepath = process.argv[2];
+const className = process.argv[3];
+
+if (!filepath || !className) {
+  console.error(
+    "Usage: node extract_serializable_fields.ts <filepath> <className>"
+  );
+  process.exit(1);
+}
+
+const results = extractConstructorParams(filepath, className);
+
+if (results?.fields?.length) {
+  console.log(JSON.stringify(results?.fields, null, 2));
+} else {
+  console.error("No constructor parameters found");
+}

yarn.lock

@@ -13035,7 +13035,7 @@ __metadata:
     zod: ^3.22.4
     zod-to-json-schema: ^3.22.3
   peerDependencies:
-    "@langchain/core": ">=0.3.29 <0.4.0"
+    "@langchain/core": ">=0.3.39 <0.4.0"
   languageName: unknown
   linkType: soft
 
@@ -13200,6 +13200,7 @@ __metadata:
     tsx: ^4.16.2
     typescript: ^5.4.5
   bin:
+    extract_serializable_fields: bin/extract_serializable_fields.js
     filter_spam_comment: bin/filter_spam_comment.js
     lc_build: bin/build.js
     notebook_validate: bin/validate_notebook.js