diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 93537565..f2107d55 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Added
+
+- `--no-extensions` flag to disable extension discovery and loading
+
 ## [0.37.8] - 2026-01-07
 
 ## [0.37.7] - 2026-01-07
diff --git a/packages/coding-agent/src/cli/args.ts b/packages/coding-agent/src/cli/args.ts
index cbb11a79..e8da9a08 100644
--- a/packages/coding-agent/src/cli/args.ts
+++ b/packages/coding-agent/src/cli/args.ts
@@ -27,6 +27,7 @@ export interface Args {
 	models?: string[];
 	tools?: ToolName[];
 	extensions?: string[];
+	noExtensions?: boolean;
 	print?: boolean;
 	export?: string;
 	noSkills?: boolean;
@@ -116,6 +117,8 @@ export function parseArgs(args: string[], extensionFlags?: Map<string, { type: "
 		} else if ((arg === "--extension" || arg === "-e") && i + 1 < args.length) {
 			result.extensions = result.extensions ?? [];
 			result.extensions.push(args[++i]);
+		} else if (arg === "--no-extensions") {
+			result.noExtensions = true;
 		} else if (arg === "--no-skills") {
 			result.noSkills = true;
 		} else if (arg === "--skills" && i + 1 < args.length) {
@@ -175,6 +178,7 @@ ${chalk.bold("Options:")}
                                  Available: read, bash, edit, write, grep, find, ls
   --thinking <level>             Set thinking level: off, minimal, low, medium, high, xhigh
   --extension, -e <path>         Load an extension file (can be used multiple times)
+  --no-extensions                Disable extensions discovery and loading
   --no-skills                    Disable skills discovery and loading
   --skills <patterns>            Comma-separated glob patterns to filter skills (e.g., git-*,docker)
   --export <file>                Export session file to HTML and exit
diff --git a/packages/coding-agent/src/main.ts b/packages/coding-agent/src/main.ts
index da8d0e6c..d6f2ae9b 100644
--- a/packages/coding-agent/src/main.ts
+++ b/packages/coding-agent/src/main.ts
@@ -294,8 +294,11 @@ function buildSessionOptions(
 		options.skills = [];
 	}
 
-	// Pre-loaded extensions (from early CLI flag discovery)
-	if (preloadedExtensions && preloadedExtensions.length > 0) {
+	// Extensions
+	if (parsed.noExtensions) {
+		options.extensions = [];
+	} else if (preloadedExtensions && preloadedExtensions.length > 0) {
+		// Pre-loaded extensions (from early CLI flag discovery)
 		options.preloadedExtensions = preloadedExtensions;
 	}
 
@@ -317,16 +320,21 @@ export async function main(args: string[]) {
 	const firstPass = parseArgs(args);
 	time("parseArgs-firstPass");
 
-	// Early load extensions to discover their CLI flags
+	// Early load extensions to discover their CLI flags (unless --no-extensions)
 	const cwd = process.cwd();
 	const agentDir = getAgentDir();
 	const eventBus = createEventBus();
 	const settingsManager = SettingsManager.create(cwd);
 	time("SettingsManager.create");
-	// Merge CLI --extension args with settings.json extensions
-	const extensionPaths = [...settingsManager.getExtensionPaths(), ...(firstPass.extensions ?? [])];
-	const { extensions: loadedExtensions } = await discoverAndLoadExtensions(extensionPaths, cwd, agentDir, eventBus);
-	time("discoverExtensionFlags");
+
+	let loadedExtensions: LoadedExtension[] = [];
+	if (!firstPass.noExtensions) {
+		// Merge CLI --extension args with settings.json extensions
+		const extensionPaths = [...settingsManager.getExtensionPaths(), ...(firstPass.extensions ?? [])];
+		const result = await discoverAndLoadExtensions(extensionPaths, cwd, agentDir, eventBus);
+		loadedExtensions = result.extensions;
+		time("discoverExtensionFlags");
+	}
 
 	// Collect all extension flags
 	const extensionFlags = new Map<string, { type: "boolean" | "string" }>();
diff --git a/packages/coding-agent/test/args.test.ts b/packages/coding-agent/test/args.test.ts
index 9f809a51..2b3a8af6 100644
--- a/packages/coding-agent/test/args.test.ts
+++ b/packages/coding-agent/test/args.test.ts
@@ -150,6 +150,20 @@ describe("parseArgs", () => {
 		});
 	});
 
+	describe("--no-extensions flag", () => {
+		test("parses --no-extensions flag", () => {
+			const result = parseArgs(["--no-extensions"]);
+			expect(result.noExtensions).toBe(true);
+		});
+	});
+
+	describe("--no-skills flag", () => {
+		test("parses --no-skills flag", () => {
+			const result = parseArgs(["--no-skills"]);
+			expect(result.noSkills).toBe(true);
+		});
+	});
+
 	describe("messages and file args", () => {
 		test("parses plain text messages", () => {
 			const result = parseArgs(["hello", "world"]);