fix(google-genai): sanitize JSON schema by removing unsupported propertyNames and patternProperties for Gemini tool-calling

Author: Nitinref

libs/providers/langchain-google-genai/src/chat_models.ts

@@ -63,6 +63,7 @@ import {
 } from "./types.js";
 import { convertToolsToGenAI } from "./utils/tools.js";
 import PROFILES from "./profiles.js";
+import { cleanGeminiSchema } from "./cleanGeminiSchema";
 
 interface TokenUsage {
   completionTokens?: number;
@@ -1093,7 +1094,7 @@ export class ChatGoogleGenerativeAI
                 name: functionName,
                 description:
                   jsonSchema.description ?? "A function available to call.",
-                parameters: jsonSchema as GenerativeAIFunctionDeclarationSchema,
+                parameters: cleanGeminiSchema(jsonSchema) as GenerativeAIFunctionDeclarationSchema,
               },
             ],
           },

libs/providers/langchain-google-genai/src/cleanGeminiSchema.ts

@@ -0,0 +1,22 @@
+export function cleanGeminiSchema(schema: any): any {
+  if (!schema || typeof schema !== "object") {
+    return schema;
+  }
+
+  const cleaned: any = Array.isArray(schema)
+    ? schema.map((item) => cleanGeminiSchema(item))
+    : { ...schema };
+
+
+  delete cleaned.propertyNames;
+  delete cleaned.patternProperties;
+
+  
+  for (const key of Object.keys(cleaned)) {
+    if (typeof cleaned[key] === "object") {
+      cleaned[key] = cleanGeminiSchema(cleaned[key]);
+    }
+  }
+
+  return cleaned;
+}

libs/providers/langchain-google-genai/src/utils/common.ts

@@ -39,6 +39,7 @@ import { isLangChainTool } from "@langchain/core/utils/function_calling";
 import { isOpenAITool } from "@langchain/core/language_models/base";
 import { ToolCallChunk } from "@langchain/core/messages/tool";
 import { v4 as uuidv4 } from "uuid";
+import { cleanGeminiSchema } from "../cleanGeminiSchema.js";
 import {
   jsonSchemaToGeminiParameters,
   schemaToGenerativeAIParameters,
@@ -358,8 +359,8 @@ export function convertMessageContentToParts(
 
     const result = Array.isArray(message.content)
       ? (message.content
-          .map((c) => _convertLangChainContentToPart(c, isMultimodalModel))
-          .filter((p) => p !== undefined) as Part[])
+        .map((c) => _convertLangChainContentToPart(c, isMultimodalModel))
+        .filter((p) => p !== undefined) as Part[])
       : message.content;
 
     if (message.status === "error") {
@@ -799,7 +800,8 @@ export function convertToGenerativeAITools(
             return {
               name: tool.name,
               description: tool.description,
-              parameters: jsonSchema,
+              parameters: cleanGeminiSchema(jsonSchema),
+
             };
           }
           if (isOpenAITool(tool)) {