diff --git a/src/workerd/api/container.c++ b/src/workerd/api/container.c++
index 9838373e059..21335b1d42d 100644
--- a/src/workerd/api/container.c++
+++ b/src/workerd/api/container.c++
@@ -5,6 +5,7 @@
 #include "container.h"
 
 #include <workerd/api/http.h>
+#include <workerd/io/features.h>
 #include <workerd/io/io-context.h>
 
 namespace workerd::api {
@@ -17,6 +18,7 @@ Container::Container(rpc::Container::Client rpcClient, bool running)
       running(running) {}
 
 void Container::start(jsg::Lock& js, jsg::Optional<StartupOptions> maybeOptions) {
+  auto flags = FeatureFlags::get(js);
   JSG_REQUIRE(!running, Error, "start() cannot be called on a container that is already running.");
 
   StartupOptions options = kj::mv(maybeOptions).orDefault({});
@@ -50,6 +52,13 @@ void Container::start(jsg::Lock& js, jsg::Optional<StartupOptions> maybeOptions)
   IoContext::current().addTask(req.sendIgnoringResult());
 
   running = true;
+
+  if (flags.getWorkerdExperimental()) {
+    KJ_IF_SOME(hardTimeoutMs, options.hardTimeout) {
+      JSG_REQUIRE(hardTimeoutMs > 0, TypeError, "Hard timeout must be greater than 0");
+      req.setHardTimeoutMs(hardTimeoutMs);
+    }
+  }
 }
 
 jsg::Promise<void> Container::setInactivityTimeout(jsg::Lock& js, int64_t durationMs) {
diff --git a/src/workerd/api/container.h b/src/workerd/api/container.h
index 4158f3ba105..7494080e6b4 100644
--- a/src/workerd/api/container.h
+++ b/src/workerd/api/container.h
@@ -28,10 +28,27 @@ class Container: public jsg::Object {
     jsg::Optional<kj::Array<kj::String>> entrypoint;
     bool enableInternet = false;
     jsg::Optional<jsg::Dict<kj::String>> env;
+    jsg::Optional<int64_t> hardTimeout;
 
     // TODO(containers): Allow intercepting stdin/stdout/stderr by specifying streams here.
 
-    JSG_STRUCT(entrypoint, enableInternet, env);
+    JSG_STRUCT(entrypoint, enableInternet, env, hardTimeout);
+    JSG_STRUCT_TS_OVERRIDE_DYNAMIC(CompatibilityFlags::Reader flags) {
+      if (flags.getWorkerdExperimental()) {
+        JSG_TS_OVERRIDE(ContainerStartupOptions {
+          entrypoint?: string[];
+          enableInternet: boolean;
+          env?: Record<string, string>;
+          hardTimeout?: number;
+        });
+      } else {
+        JSG_TS_OVERRIDE(ContainerStartupOptions {
+          entrypoint?: string[];
+          enableInternet: boolean;
+          env?: Record<string, string>;
+        });
+      }
+    }
   };
 
   bool getRunning() {
diff --git a/src/workerd/io/container.capnp b/src/workerd/io/container.capnp
index a68d09a57b6..f79e85defb2 100644
--- a/src/workerd/io/container.capnp
+++ b/src/workerd/io/container.capnp
@@ -34,6 +34,12 @@ interface Container @0x9aaceefc06523bca {
     # If null, the container will start with the environment variables defined in its image.
     # The format is defined as a list of `NAME=VALUE`.
     # The container runtime should validate the environment variables input.
+
+    hardTimeoutMs @3 :Int64;
+    # Configures an absolute timeout that starts when the container starts and never resets.
+    # The container will be forcefully terminated when this timeout expires, regardless of activity.
+    # Unlike inactivity timeout, this is a hard deadline from container startup.
+    # If 0 (default), no hard timeout is applied.
   }
 
   monitor @2 () -> (exitCode: Int32);
diff --git a/types/generated-snapshot/experimental/index.d.ts b/types/generated-snapshot/experimental/index.d.ts
index b52eae3f10b..4af44b9dac1 100755
--- a/types/generated-snapshot/experimental/index.d.ts
+++ b/types/generated-snapshot/experimental/index.d.ts
@@ -3840,6 +3840,7 @@ interface ContainerStartupOptions {
   entrypoint?: string[];
   enableInternet: boolean;
   env?: Record<string, string>;
+  hardTimeout?: number;
 }
 /**
  * The **`FileSystemHandle`** interface of the File System API is an object which represents a file or directory entry.
diff --git a/types/generated-snapshot/experimental/index.ts b/types/generated-snapshot/experimental/index.ts
index 22e313aec87..3d052ca7167 100755
--- a/types/generated-snapshot/experimental/index.ts
+++ b/types/generated-snapshot/experimental/index.ts
@@ -3851,6 +3851,7 @@ export interface ContainerStartupOptions {
   entrypoint?: string[];
   enableInternet: boolean;
   env?: Record<string, string>;
+  hardTimeout?: number;
 }
 /**
  * The **`FileSystemHandle`** interface of the File System API is an object which represents a file or directory entry.
diff --git a/types/generated-snapshot/latest/index.d.ts b/types/generated-snapshot/latest/index.d.ts
index db9c6f368b3..2239c3aadd3 100755
--- a/types/generated-snapshot/latest/index.d.ts
+++ b/types/generated-snapshot/latest/index.d.ts
@@ -3734,6 +3734,7 @@ interface ContainerStartupOptions {
   entrypoint?: string[];
   enableInternet: boolean;
   env?: Record<string, string>;
+  hardTimeout?: number | bigint;
 }
 /**
  * The **`MessagePort`** interface of the Channel Messaging API represents one of the two ports of a MessageChannel, allowing messages to be sent from one port and listening out for them arriving at the other.
diff --git a/types/generated-snapshot/latest/index.ts b/types/generated-snapshot/latest/index.ts
index 20316383a3b..2cebba66e85 100755
--- a/types/generated-snapshot/latest/index.ts
+++ b/types/generated-snapshot/latest/index.ts
@@ -3745,6 +3745,7 @@ export interface ContainerStartupOptions {
   entrypoint?: string[];
   enableInternet: boolean;
   env?: Record<string, string>;
+  hardTimeout?: number | bigint;
 }
 /**
  * The **`MessagePort`** interface of the Channel Messaging API represents one of the two ports of a MessageChannel, allowing messages to be sent from one port and listening out for them arriving at the other.