diff --git a/api/src/secure-startup.test.ts b/api/src/secure-startup.test.ts
index c1558e85..e1291712 100644
--- a/api/src/secure-startup.test.ts
+++ b/api/src/secure-startup.test.ts
@@ -113,6 +113,18 @@ describe('hardened sandbox-runner startup config', () => {
     expect(() => validateHardenedSandboxStartup()).toThrow('REDIS_HOST');
   });
 
+  test('allows Lambda MicroVM image metadata while rejecting AWS credentials', () => {
+    setValidHardenedConfig();
+    process.env.AWS_LAMBDA_MICROVM_IMAGE_ARN = 'arn:aws:lambda:us-east-1:123456789012:microvm-image:codeapi';
+    process.env.AWS_LAMBDA_MICROVM_IMAGE_NAME = 'codeapi';
+    process.env.AWS_LAMBDA_MICROVM_IMAGE_VERSION = '3';
+    process.env.AWS_REGION = 'us-east-1';
+    expect(() => validateHardenedSandboxStartup()).not.toThrow();
+
+    process.env.AWS_ACCESS_KEY_ID = 'access-key';
+    expect(() => validateHardenedSandboxStartup()).toThrow('AWS_ACCESS_KEY_ID');
+  });
+
   test('rejects missing manifest verifier and wrong forwarding target', () => {
     setValidHardenedConfig();
     config.egress_gateway_url = '';
diff --git a/api/src/secure-startup.ts b/api/src/secure-startup.ts
index 04f5638a..326bf810 100644
--- a/api/src/secure-startup.ts
+++ b/api/src/secure-startup.ts
@@ -1,6 +1,13 @@
 import { config } from './config';
 import { workspaceIsolationConfigErrors } from './workspace-isolation';
 
+const ALLOWED_LAMBDA_MICROVM_AWS_ENV = new Set([
+  'AWS_LAMBDA_MICROVM_IMAGE_ARN',
+  'AWS_LAMBDA_MICROVM_IMAGE_NAME',
+  'AWS_LAMBDA_MICROVM_IMAGE_VERSION',
+  'AWS_REGION',
+]);
+
 export class SandboxSecureStartupError extends Error {
   constructor(message: string) {
     super(message);
@@ -57,7 +64,7 @@ function forbiddenEnvNames(): string[] {
     if (name === 'CODEAPI_HARDENED_SANDBOX_MODE') continue;
     if (name.startsWith('CODEAPI_')) forbidden.push(name);
     if (name.startsWith('REDIS_')) forbidden.push(name);
-    if (name.startsWith('AWS_')) forbidden.push(name);
+    if (name.startsWith('AWS_') && !ALLOWED_LAMBDA_MICROVM_AWS_ENV.has(name)) forbidden.push(name);
     if (name.startsWith('S3_')) forbidden.push(name);
     if (name.startsWith('MINIO_')) forbidden.push(name);
     if (/(SECRET|TOKEN|PASSWORD|PRIVATE_KEY)/.test(name)) forbidden.push(name);