diff --git a/src/cli.ts b/src/cli.ts
index caf480d7..fa5fa9a2 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -389,10 +389,12 @@ program
   )
   .option(
     '--agent-base-image <image>',
-    'Base image for agent container when using --build-local. Options:\n' +
+    'Base image for agent container. Options:\n' +
     '                                   ubuntu:22.04 (default): Minimal, ~200MB\n' +
-    '                                   ghcr.io/catthehacker/ubuntu:runner-22.04: Closer to GitHub Actions, ~2-5GB\n' +
-    '                                   ghcr.io/catthehacker/ubuntu:full-22.04: Near-identical to GitHub Actions, ~20GB',
+    '                                   act: Pre-built image with GitHub Actions parity (uses GHCR agent-act image)\n' +
+    '                                   With --build-local, can also use:\n' +
+    '                                   ghcr.io/catthehacker/ubuntu:runner-22.04: ~2-5GB\n' +
+    '                                   ghcr.io/catthehacker/ubuntu:full-22.04: ~20GB',
     'ubuntu:22.04'
   )
   .option(
@@ -683,19 +685,27 @@ program
       allowedUrls,
     };
 
-    // Validate and warn if using custom agent base image
+    // Validate and handle custom agent base image
     if (options.agentBaseImage && options.agentBaseImage !== 'ubuntu:22.04') {
-      // Validate against approved base images for supply chain security
-      const validation = validateAgentBaseImage(options.agentBaseImage);
-      if (!validation.valid) {
-        logger.error(validation.error!);
-        process.exit(1);
-      }
-      
-      if (options.buildLocal) {
-        logger.info(`Using custom agent base image: ${options.agentBaseImage}`);
+      // Special case: 'act' uses pre-built GHCR image (no --build-local needed)
+      if (options.agentBaseImage === 'act') {
+        config.useAgentActImage = true;
+        logger.info('Using pre-built agent-act image with GitHub Actions parity');
       } else {
-        logger.warn('⚠️  --agent-base-image is only used with --build-local. Ignoring.');
+        // Validate against approved base images for supply chain security
+        const validation = validateAgentBaseImage(options.agentBaseImage);
+        if (!validation.valid) {
+          logger.error(validation.error!);
+          process.exit(1);
+        }
+
+        if (options.buildLocal) {
+          logger.info(`Using custom agent base image: ${options.agentBaseImage}`);
+        } else {
+          logger.warn('⚠️  --agent-base-image requires --build-local for custom images.');
+          logger.warn('   Use --agent-base-image act for pre-built GitHub Actions parity image.');
+          process.exit(1);
+        }
       }
     }
 
diff --git a/src/docker-manager.test.ts b/src/docker-manager.test.ts
index 1029e036..d24651ad 100644
--- a/src/docker-manager.test.ts
+++ b/src/docker-manager.test.ts
@@ -238,6 +238,21 @@ describe('docker-manager', () => {
       expect(result.services.agent.build?.args?.BASE_IMAGE).toBe('ghcr.io/catthehacker/ubuntu:full-22.04@sha256:a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1');
     });
 
+    it('should use agent-act image when useAgentActImage is true', () => {
+      const actImageConfig = { ...mockConfig, useAgentActImage: true };
+      const result = generateDockerCompose(actImageConfig, mockNetworkConfig);
+
+      expect(result.services.agent.image).toBe('ghcr.io/githubnext/gh-aw-firewall/agent-act:latest');
+      expect(result.services.agent.build).toBeUndefined();
+    });
+
+    it('should use default agent image when useAgentActImage is false', () => {
+      const defaultConfig = { ...mockConfig, useAgentActImage: false };
+      const result = generateDockerCompose(defaultConfig, mockNetworkConfig);
+
+      expect(result.services.agent.image).toBe('ghcr.io/githubnext/gh-aw-firewall/agent:latest');
+    });
+
     it('should not pass BASE_IMAGE when agentBaseImage is explicitly set to default ubuntu:22.04', () => {
       const customBaseImageConfig = {
         ...mockConfig,
diff --git a/src/docker-manager.ts b/src/docker-manager.ts
index 5bbb7b05..2da359e3 100644
--- a/src/docker-manager.ts
+++ b/src/docker-manager.ts
@@ -420,7 +420,9 @@ export function generateDockerCompose(
 
   // Use GHCR image or build locally
   if (useGHCR) {
-    agentService.image = `${registry}/agent:${tag}`;
+    // Use agent-act image if requested for GitHub Actions parity
+    const agentImageName = config.useAgentActImage ? 'agent-act' : 'agent';
+    agentService.image = `${registry}/${agentImageName}:${tag}`;
   } else {
     const buildArgs: Record<string, string> = {
       // Pass host UID/GID to match file ownership in container
diff --git a/src/types.ts b/src/types.ts
index 966b195f..810f7b74 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -149,20 +149,33 @@ export interface WrapperConfig {
 
   /**
    * Base image for the agent container when building locally
-   * 
+   *
    * Allows customization of the agent container base image for closer parity
    * with GitHub Actions runner environments. Only used when buildLocal is true.
-   * 
+   *
    * Options:
    * - 'ubuntu:22.04' (default): Minimal image, smallest size (~200MB)
    * - 'ghcr.io/catthehacker/ubuntu:runner-22.04': Closer to GitHub Actions runner (~2-5GB)
    * - 'ghcr.io/catthehacker/ubuntu:full-22.04': Near-identical to GitHub Actions runner (~20GB compressed)
-   * 
+   *
    * @default 'ubuntu:22.04'
    * @example 'ghcr.io/catthehacker/ubuntu:runner-22.04'
    */
   agentBaseImage?: string;
 
+  /**
+   * Use the pre-built agent-act image from GHCR for GitHub Actions parity
+   *
+   * When true, uses ghcr.io/githubnext/gh-aw-firewall/agent-act instead of
+   * the default agent image. This image is built with catthehacker/ubuntu:act-24.04
+   * as the base for better GitHub Actions runner compatibility.
+   *
+   * Set via --agent-base-image act
+   *
+   * @default false
+   */
+  useAgentActImage?: boolean;
+
   /**
    * Additional environment variables to pass to the agent execution container
    *