From a4542a61acbc0410beae5056e52d7f98c71bd132 Mon Sep 17 00:00:00 2001
From: nitin yadav <nitinyadav484220@gmail.com>
Date: Mon, 1 Dec 2025 16:22:56 +0530
Subject: [PATCH 1/2] fix(google-genai): sanitize JSON schema by removing
 unsupported propertyNames and patternProperties for Gemini tool-calling

---
 .../langchain-google-genai/src/chat_models.ts |  3 ++-
 .../src/cleanGeminiSchema.ts                  | 22 +++++++++++++++++++
 .../src/utils/common.ts                       |  8 ++++---
 3 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 libs/providers/langchain-google-genai/src/cleanGeminiSchema.ts

diff --git a/libs/providers/langchain-google-genai/src/chat_models.ts b/libs/providers/langchain-google-genai/src/chat_models.ts
index 55e93f19d6be..979326e2988c 100644
--- a/libs/providers/langchain-google-genai/src/chat_models.ts
+++ b/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,
               },
             ],
           },
diff --git a/libs/providers/langchain-google-genai/src/cleanGeminiSchema.ts b/libs/providers/langchain-google-genai/src/cleanGeminiSchema.ts
new file mode 100644
index 000000000000..4e85cd7b9a0c
--- /dev/null
+++ b/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;
+}
diff --git a/libs/providers/langchain-google-genai/src/utils/common.ts b/libs/providers/langchain-google-genai/src/utils/common.ts
index f59042aeb3f7..9ab3223e4b6d 100644
--- a/libs/providers/langchain-google-genai/src/utils/common.ts
+++ b/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)) {

From e7edff015a0aa59760553fa8e4b1bb721104f32a Mon Sep 17 00:00:00 2001
From: nitin yadav <nitinyadav484220@gmail.com>
Date: Tue, 16 Dec 2025 23:56:59 +0530
Subject: [PATCH 2/2] test(google-genai): add regression test for
 cleanGeminiSchema

---
 .../src/tests/cleanGeminiSchema.test.ts       | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 libs/providers/langchain-google-genai/src/tests/cleanGeminiSchema.test.ts

diff --git a/libs/providers/langchain-google-genai/src/tests/cleanGeminiSchema.test.ts b/libs/providers/langchain-google-genai/src/tests/cleanGeminiSchema.test.ts
new file mode 100644
index 000000000000..87257f02adcc
--- /dev/null
+++ b/libs/providers/langchain-google-genai/src/tests/cleanGeminiSchema.test.ts
@@ -0,0 +1,50 @@
+import { cleanGeminiSchema } from "../cleanGeminiSchema";
+
+describe("cleanGeminiSchema", () => {
+  it("removes propertyNames from schema", () => {
+    const schema = {
+      type: "object",
+      propertyNames: {
+        pattern: "^[a-zA-Z]+$",
+      },
+      properties: {
+        name: { type: "string" },
+      },
+    };
+
+    const cleaned = cleanGeminiSchema(schema as any);
+
+    expect(cleaned.propertyNames).toBeUndefined();
+    expect(cleaned.properties).toBeDefined();
+  });
+
+  it("removes patternProperties from schema", () => {
+    const schema = {
+      type: "object",
+      patternProperties: {
+        "^S_": { type: "string" },
+      },
+      properties: {
+        id: { type: "number" },
+      },
+    };
+
+    const cleaned = cleanGeminiSchema(schema as any);
+
+    expect(cleaned.patternProperties).toBeUndefined();
+    expect(cleaned.properties).toBeDefined();
+  });
+
+  it("does not modify schema without unsupported fields", () => {
+    const schema = {
+      type: "object",
+      properties: {
+        age: { type: "number" },
+      },
+    };
+
+    const cleaned = cleanGeminiSchema(schema as any);
+
+    expect(cleaned).toEqual(schema);
+  });
+});