diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index fbac67a80..2417b5b67 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -248,13 +248,13 @@ importers:
         version: 0.4.9(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))(zod-to-json-schema@3.24.6(zod@3.25.76))
       '@langchain/mcp-adapters':
         specifier: ^0.6.0
-        version: 0.6.0(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))
+        version: 0.6.0(@cfworker/json-schema@4.1.1)(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))
       '@langchain/textsplitters':
         specifier: 0.1.0
         version: 0.1.0(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))
       '@modelcontextprotocol/sdk':
-        specifier: ^1.20.2
-        version: 1.20.2
+        specifier: ^1.21.1
+        version: 1.21.1(@cfworker/json-schema@4.1.1)
       '@sap-ai-sdk/ai-api':
         specifier: workspace:^
         version: link:../packages/ai-api
@@ -330,7 +330,7 @@ importers:
         version: 0.4.9(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))(zod-to-json-schema@3.24.6(zod@3.25.76))
       '@langchain/mcp-adapters':
         specifier: ^0.6.0
-        version: 0.6.0(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))
+        version: 0.6.0(@cfworker/json-schema@4.1.1)(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))
       '@langchain/textsplitters':
         specifier: 0.1.0
         version: 0.1.0(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))
@@ -1134,9 +1134,14 @@ packages:
   '@manypkg/get-packages@1.1.3':
     resolution: {integrity: sha512-fo+QhuU3qE/2TQMQmbVMqaQ6EWbMhi4ABWP+O4AM1NqPBuy0OrApV5LO6BrrgnhtAHS2NH6RrVk9OL181tTi8A==}
 
-  '@modelcontextprotocol/sdk@1.20.2':
-    resolution: {integrity: sha512-6rqTdFt67AAAzln3NOKsXRmv5ZzPkgbfaebKBqUbts7vK1GZudqnrun5a8d3M/h955cam9RHZ6Jb4Y1XhnmFPg==}
+  '@modelcontextprotocol/sdk@1.21.1':
+    resolution: {integrity: sha512-UyLFcJLDvUuZbGnaQqXFT32CpPpGj7VS19roLut6gkQVhb439xUzYWbsUvdI3ZPL+2hnFosuugtYWE0Mcs1rmQ==}
     engines: {node: '>=18'}
+    peerDependencies:
+      '@cfworker/json-schema': ^4.1.1
+    peerDependenciesMeta:
+      '@cfworker/json-schema':
+        optional: true
 
   '@mswjs/interceptors@0.39.8':
     resolution: {integrity: sha512-2+BzZbjRO7Ct61k8fMNHEtoKjeWI9pIlHFTqBwZ5icHpqszIgEZbjb1MW5Z0+bITTCTl3gk4PDBxs9tA/csXvA==}
@@ -1808,6 +1813,14 @@ packages:
       ajv:
         optional: true
 
+  ajv-formats@3.0.1:
+    resolution: {integrity: sha512-8iUql50EUR+uUcdRQ3HDqa6EVyo3docL8g5WJ3FNcWmu62IbkGUue/pEyLBW8VGKKucTPgqeks4fIU1DA4yowQ==}
+    peerDependencies:
+      ajv: ^8.0.0
+    peerDependenciesMeta:
+      ajv:
+        optional: true
+
   ajv@6.12.6:
     resolution: {integrity: sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==}
 
@@ -5995,15 +6008,16 @@ snapshots:
       - react
       - react-dom
 
-  '@langchain/mcp-adapters@0.6.0(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))':
+  '@langchain/mcp-adapters@0.6.0(@cfworker/json-schema@4.1.1)(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))':
     dependencies:
       '@langchain/core': 0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76))
-      '@modelcontextprotocol/sdk': 1.20.2
+      '@modelcontextprotocol/sdk': 1.21.1(@cfworker/json-schema@4.1.1)
       debug: 4.4.3
       zod: 3.25.76
     optionalDependencies:
       extended-eventsource: 1.7.0
     transitivePeerDependencies:
+      - '@cfworker/json-schema'
       - supports-color
 
   '@langchain/openai@0.6.16(@langchain/core@0.3.79(openai@5.12.2(ws@8.18.3)(zod@3.25.76)))(ws@8.18.3)':
@@ -6036,9 +6050,10 @@ snapshots:
       globby: 11.1.0
       read-yaml-file: 1.1.0
 
-  '@modelcontextprotocol/sdk@1.20.2':
+  '@modelcontextprotocol/sdk@1.21.1(@cfworker/json-schema@4.1.1)':
     dependencies:
-      ajv: 6.12.6
+      ajv: 8.17.1
+      ajv-formats: 3.0.1(ajv@8.17.1)
       content-type: 1.0.5
       cors: 2.8.5
       cross-spawn: 7.0.6
@@ -6050,6 +6065,8 @@ snapshots:
       raw-body: 3.0.1
       zod: 3.25.76
       zod-to-json-schema: 3.24.6(zod@3.25.76)
+    optionalDependencies:
+      '@cfworker/json-schema': 4.1.1
     transitivePeerDependencies:
       - supports-color
 
@@ -7114,6 +7131,10 @@ snapshots:
     optionalDependencies:
       ajv: 8.17.1
 
+  ajv-formats@3.0.1(ajv@8.17.1):
+    optionalDependencies:
+      ajv: 8.17.1
+
   ajv@6.12.6:
     dependencies:
       fast-deep-equal: 3.1.3
diff --git a/sample-code/package.json b/sample-code/package.json
index 68b3f9ffd..7847f06c5 100644
--- a/sample-code/package.json
+++ b/sample-code/package.json
@@ -23,7 +23,7 @@
   "dependencies": {
     "@langchain/langgraph": "^0.4.9",
     "@langchain/mcp-adapters": "^0.6.0",
-    "@modelcontextprotocol/sdk": "^1.20.2",
+    "@modelcontextprotocol/sdk": "^1.21.1",
     "langchain": "0.3.36",
     "@langchain/core": "0.3.79",
     "@langchain/textsplitters": "0.1.0",