diff --git a/package-lock.json b/package-lock.json
index 8ed1fa1..601e08c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,7 +9,7 @@
       "version": "0.1.15",
       "license": "MIT",
       "dependencies": {
-        "@modelcontextprotocol/sdk": "1.19.1"
+        "@modelcontextprotocol/sdk": "1.21.0"
       },
       "bin": {
         "cli-microsoft365-mcp-server": "dist/index.js"
@@ -65,12 +65,13 @@
       }
     },
     "node_modules/@modelcontextprotocol/sdk": {
-      "version": "1.19.1",
-      "resolved": "https://registry.npmjs.org/@modelcontextprotocol/sdk/-/sdk-1.19.1.tgz",
-      "integrity": "sha512-3Y2h3MZKjec1eAqSTBclATlX+AbC6n1LgfVzRMJLt3v6w0RCYgwLrjbxPDbhsYHt6Wdqc/aCceNJYgj448ELQQ==",
+      "version": "1.21.0",
+      "resolved": "https://registry.npmjs.org/@modelcontextprotocol/sdk/-/sdk-1.21.0.tgz",
+      "integrity": "sha512-YFBsXJMFCyI1zP98u7gezMFKX4lgu/XpoZJk7ufI6UlFKXLj2hAMUuRlQX/nrmIPOmhRrG6tw2OQ2ZA/ZlXYpQ==",
       "license": "MIT",
       "dependencies": {
-        "ajv": "^6.12.6",
+        "ajv": "^8.17.1",
+        "ajv-formats": "^3.0.1",
         "content-type": "^1.0.5",
         "cors": "^2.8.5",
         "cross-spawn": "^7.0.5",
@@ -85,6 +86,14 @@
       },
       "engines": {
         "node": ">=18"
+      },
+      "peerDependencies": {
+        "@cfworker/json-schema": "^4.1.1"
+      },
+      "peerDependenciesMeta": {
+        "@cfworker/json-schema": {
+          "optional": true
+        }
       }
     },
     "node_modules/@tsconfig/node10": {
@@ -165,21 +174,38 @@
       }
     },
     "node_modules/ajv": {
-      "version": "6.12.6",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
-      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
+      "version": "8.17.1",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-8.17.1.tgz",
+      "integrity": "sha512-B/gBuNg5SiMTrPkC+A2+cW0RszwxYmn6VYxB/inlBStS5nx6xHIt/ehKRhIMhqusl7a8LjQoZnjCs5vhwxOQ1g==",
       "license": "MIT",
       "dependencies": {
-        "fast-deep-equal": "^3.1.1",
-        "fast-json-stable-stringify": "^2.0.0",
-        "json-schema-traverse": "^0.4.1",
-        "uri-js": "^4.2.2"
+        "fast-deep-equal": "^3.1.3",
+        "fast-uri": "^3.0.1",
+        "json-schema-traverse": "^1.0.0",
+        "require-from-string": "^2.0.2"
       },
       "funding": {
         "type": "github",
         "url": "https://github.com/sponsors/epoberezkin"
       }
     },
+    "node_modules/ajv-formats": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/ajv-formats/-/ajv-formats-3.0.1.tgz",
+      "integrity": "sha512-8iUql50EUR+uUcdRQ3HDqa6EVyo3docL8g5WJ3FNcWmu62IbkGUue/pEyLBW8VGKKucTPgqeks4fIU1DA4yowQ==",
+      "license": "MIT",
+      "dependencies": {
+        "ajv": "^8.0.0"
+      },
+      "peerDependencies": {
+        "ajv": "^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "ajv": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/arg": {
       "version": "4.1.3",
       "resolved": "https://registry.npmjs.org/arg/-/arg-4.1.3.tgz",
@@ -512,11 +538,21 @@
       "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==",
       "license": "MIT"
     },
-    "node_modules/fast-json-stable-stringify": {
-      "version": "2.1.0",
-      "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.1.0.tgz",
-      "integrity": "sha512-lhd/wF+Lk98HZoTCtlVraHtfh5XYijIjalXck7saUtuanSDyLMxnHhSXEDJqHxD7msR8D0uCmqlkwjCV8xvwHw==",
-      "license": "MIT"
+    "node_modules/fast-uri": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/fast-uri/-/fast-uri-3.1.0.tgz",
+      "integrity": "sha512-iPeeDKJSWf4IEOasVVrknXpaBV0IApz/gp7S2bb7Z4Lljbl2MGJRqInZiUrQwV16cpzw/D3S5j5Julj/gT52AA==",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/fastify"
+        },
+        {
+          "type": "opencollective",
+          "url": "https://opencollective.com/fastify"
+        }
+      ],
+      "license": "BSD-3-Clause"
     },
     "node_modules/finalhandler": {
       "version": "2.1.0",
@@ -700,9 +736,9 @@
       "license": "ISC"
     },
     "node_modules/json-schema-traverse": {
-      "version": "0.4.1",
-      "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.4.1.tgz",
-      "integrity": "sha512-xbbCH5dCYU5T8LcEhhuh7HJ88HXuW3qsI3Y0zOZFKfZEHcpWiHU/Jxzk629Brsab/mMiHQti9wMP+845RPe3Vg==",
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-1.0.0.tgz",
+      "integrity": "sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug==",
       "license": "MIT"
     },
     "node_modules/make-error": {
@@ -869,15 +905,6 @@
         "node": ">= 0.10"
       }
     },
-    "node_modules/punycode": {
-      "version": "2.3.1",
-      "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.3.1.tgz",
-      "integrity": "sha512-vYt7UD1U9Wg6138shLtLOvdAu+8DsC/ilFtEVHcH+wydcSpNE20AfSOduf6MkRFahL5FY7X1oU7nKVZFtfq8Fg==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=6"
-      }
-    },
     "node_modules/qs": {
       "version": "6.14.0",
       "resolved": "https://registry.npmjs.org/qs/-/qs-6.14.0.tgz",
@@ -917,6 +944,15 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/require-from-string": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/require-from-string/-/require-from-string-2.0.2.tgz",
+      "integrity": "sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/router": {
       "version": "2.2.0",
       "resolved": "https://registry.npmjs.org/router/-/router-2.2.0.tgz",
@@ -1201,15 +1237,6 @@
         "node": ">= 0.8"
       }
     },
-    "node_modules/uri-js": {
-      "version": "4.4.1",
-      "resolved": "https://registry.npmjs.org/uri-js/-/uri-js-4.4.1.tgz",
-      "integrity": "sha512-7rKUyy33Q1yc98pQ1DAmLtwX109F7TIfWlW1Ydo8Wl1ii1SeHieeh0HHfPeL2fMXK6z0s8ecKs9frCuLJvndBg==",
-      "license": "BSD-2-Clause",
-      "dependencies": {
-        "punycode": "^2.1.0"
-      }
-    },
     "node_modules/v8-compile-cache-lib": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/v8-compile-cache-lib/-/v8-compile-cache-lib-3.0.1.tgz",
diff --git a/package.json b/package.json
index 9ae4f2d..a10a717 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,7 @@
     "inspect": "npx -y @modelcontextprotocol/inspector node dist/index.js"
   },
   "dependencies": {
-    "@modelcontextprotocol/sdk": "1.19.1"
+    "@modelcontextprotocol/sdk": "1.21.0"
   },
   "devDependencies": {
     "@types/node": "24.7.0",