diff --git a/AGENTS.md b/AGENTS.md
index 3a46cd3..28c3b3f 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -8,6 +8,15 @@
 - Never downgrade dependencies.
 - Newly added version/features for the Extension Changelog go at the top.
 - As a general rule: some rules, attributes, lists should be in alphabetical order.
+- Format everything (except HTML) with Prettier.
+
+## Markdown Code Style
+
+- Format with Prettier.
+
+## TypeScript Code Style
+
+- Format with Prettier.
 
 ## Communication (MANDATORY)
 
@@ -28,4 +37,4 @@
 
 - No emojis in code or documentation.
 - Only implement what's requested.
-- Preserve existing structures - Don't remove unrelated code
+- Preserve existing structures - Don't remove unrelated code.
diff --git a/htmlhint-server/src/server.ts b/htmlhint-server/src/server.ts
index 26158d9..0a47243 100644
--- a/htmlhint-server/src/server.ts
+++ b/htmlhint-server/src/server.ts
@@ -1074,8 +1074,7 @@ function createLinkRelCanonicalRequireFix(
   let insertPosition: number;
   const shouldSelfClose = isRuleEnabledForDocument(document, "tag-self-close");
   const canonicalSnippet =
-    '\n    <link rel="canonical" href=""' +
-    (shouldSelfClose ? " />" : ">");
+    '\n    <link rel="canonical" href=""' + (shouldSelfClose ? " />" : ">");
 
   if (metaDescriptionMatch) {
     // Insert after description meta tag
diff --git a/htmlhint/package-lock.json b/htmlhint/package-lock.json
index c781618..615af1d 100644
--- a/htmlhint/package-lock.json
+++ b/htmlhint/package-lock.json
@@ -29,7 +29,7 @@
         "@types/node": "^22.19.1",
         "@types/vscode": "^1.101.0",
         "@vscode/test-electron": "^2.5.2",
-        "typescript": "5.5.4"
+        "typescript": "5.6.3"
       },
       "engines": {
         "vscode": "^1.101.0"
@@ -852,9 +852,9 @@
       }
     },
     "node_modules/typescript": {
-      "version": "5.5.4",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.5.4.tgz",
-      "integrity": "sha512-Mtq29sKDAEYP7aljRgtPOpTvOfbwRWlS6dPRzwjdE+C0R4brX/GUyhHSecbHMFLNBLcJIPt9nl9yG5TZ1weH+Q==",
+      "version": "5.6.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.6.3.tgz",
+      "integrity": "sha512-hjcS1mhfuyi4WW8IWtjP7brDrG2cuDZukyrYrSauoXGNgx0S7zceP07adYkJycEr56BOUTNPzbInooiN3fn1qw==",
       "dev": true,
       "license": "Apache-2.0",
       "bin": {
diff --git a/htmlhint/package.json b/htmlhint/package.json
index 37593a6..5ed08a7 100644
--- a/htmlhint/package.json
+++ b/htmlhint/package.json
@@ -94,7 +94,7 @@
     "@types/node": "^22.19.1",
     "@types/vscode": "^1.101.0",
     "@vscode/test-electron": "^2.5.2",
-    "typescript": "5.5.4"
+    "typescript": "5.6.3"
   },
   "dependencies": {
     "htmlhint": "1.8.0",
diff --git a/package-lock.json b/package-lock.json
index 208fdd4..5ee5f69 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -27,7 +27,7 @@
         "mocha": "^11.7.5",
         "prettier": "3.7.1",
         "ts-node": "^10.9.2",
-        "typescript": "5.5.4"
+        "typescript": "5.6.3"
       },
       "engines": {
         "node": ">= 22"
@@ -2778,9 +2778,9 @@
       }
     },
     "node_modules/typescript": {
-      "version": "5.5.4",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.5.4.tgz",
-      "integrity": "sha512-Mtq29sKDAEYP7aljRgtPOpTvOfbwRWlS6dPRzwjdE+C0R4brX/GUyhHSecbHMFLNBLcJIPt9nl9yG5TZ1weH+Q==",
+      "version": "5.6.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.6.3.tgz",
+      "integrity": "sha512-hjcS1mhfuyi4WW8IWtjP7brDrG2cuDZukyrYrSauoXGNgx0S7zceP07adYkJycEr56BOUTNPzbInooiN3fn1qw==",
       "dev": true,
       "license": "Apache-2.0",
       "bin": {
diff --git a/package.json b/package.json
index c920278..5304328 100644
--- a/package.json
+++ b/package.json
@@ -45,7 +45,7 @@
     "mocha": "^11.7.5",
     "prettier": "3.7.1",
     "ts-node": "^10.9.2",
-    "typescript": "5.5.4"
+    "typescript": "5.6.3"
   },
   "engines": {
     "node": ">= 22"