diff --git a/framework/py/flwr/supercore/cli/flower_superexec.py b/framework/py/flwr/supercore/cli/flower_superexec.py
index 2f25afd11229..fd480585a0a0 100644
--- a/framework/py/flwr/supercore/cli/flower_superexec.py
+++ b/framework/py/flwr/supercore/cli/flower_superexec.py
@@ -33,6 +33,7 @@
 from flwr.supercore.constant import EXEC_PLUGIN_SECTION, ExecutorType
 from flwr.supercore.exit import ExitCode, flwr_exit
 from flwr.supercore.grpc_health import add_args_health
+from flwr.supercore.runtime import RuntimeHttpStub as CoreRuntimeHttpStub
 from flwr.supercore.superexec.executor.config import (
     ExecutorConfig,
     ExecutorConfigError,
@@ -49,6 +50,9 @@
 from flwr.supercore.update_check import warn_if_flwr_update_available
 from flwr.supercore.utils import disable_process_dumping
 from flwr.supercore.version import package_version
+from flwr.superlink.runtime import RuntimeHttpStub as SuperLinkRuntimeHttpStub
+
+RuntimeStubClass = type[RuntimeStub] | type[CoreRuntimeHttpStub]
 
 
 def flower_superexec() -> None:
@@ -102,7 +106,9 @@ def flower_superexec() -> None:
             ExecPluginType.SERVER_APP,
         )
 
-    plugin_class, stub_class = _get_plugin_and_stub_class(args.plugin_type)
+    plugin_class, stub_class = _get_plugin_and_stub_class(
+        args.plugin_type, args.enable_http_api
+    )
     superexec_auth_secret = None
     if args.superexec_auth_secret_file is not None:
         try:
@@ -126,7 +132,7 @@ def flower_superexec() -> None:
 
     run_superexec(
         plugin_class=plugin_class,
-        stub_class=stub_class,  # type: ignore
+        stub_class=stub_class,
         runtime_api_address=args.runtime_api_address,
         insecure=args.insecure,
         root_certificates_path=args.root_certificates,
@@ -137,6 +143,7 @@ def flower_superexec() -> None:
         runtime_dependency_install=args.runtime_dependency_install,
         executor_type=args.executor,
         executor_config=executor_config,
+        enable_http_api=args.enable_http_api,
     )
 
 
@@ -158,6 +165,12 @@ def _parse_args() -> argparse.ArgumentParser:
         required=True,
         help="Address of the Runtime API",
     )
+    parser.add_argument(
+        "--enable-http-api",
+        action="store_true",
+        default=False,
+        help="EXPERIMENTAL: Connect to the Runtime API over HTTP instead of gRPC.",
+    )
     parser.add_argument(
         "--plugin-type",
         type=str,
@@ -221,14 +234,17 @@ def _load_executor_config(
 
 def _get_plugin_and_stub_class(
     plugin_type: str,
-) -> tuple[type[ExecPlugin], type[object]]:
+    enable_http_api: bool = False,
+) -> tuple[type[ExecPlugin], RuntimeStubClass]:
     """Get the plugin class and stub class based on the plugin type."""
-    mapping: dict[str, tuple[type[ExecPlugin], type[object]]] = {
-        ExecPluginType.CLIENT_APP: (ClientAppExecPlugin, RuntimeStub),
-        ExecPluginType.SERVER_APP: (ServerAppExecPlugin, RuntimeStub),
+    clientapp_stub = CoreRuntimeHttpStub if enable_http_api else RuntimeStub
+    serverapp_stub = SuperLinkRuntimeHttpStub if enable_http_api else RuntimeStub
+    mapping: dict[str, tuple[type[ExecPlugin], RuntimeStubClass]] = {
+        ExecPluginType.CLIENT_APP: (ClientAppExecPlugin, clientapp_stub),
+        ExecPluginType.SERVER_APP: (ServerAppExecPlugin, serverapp_stub),
         ExecPluginType.SERVER_APP_EPHEMERAL: (
             ServerAppEphemeralExecPlugin,
-            RuntimeStub,
+            serverapp_stub,
         ),
     }
     if plugin_type in mapping:
diff --git a/framework/py/flwr/supercore/cli/flower_superexec_test.py b/framework/py/flwr/supercore/cli/flower_superexec_test.py
index f78fd442bb79..29bc54752610 100644
--- a/framework/py/flwr/supercore/cli/flower_superexec_test.py
+++ b/framework/py/flwr/supercore/cli/flower_superexec_test.py
@@ -24,7 +24,9 @@
 from flwr.common.constant import ExecPluginType
 from flwr.proto.runtime_pb2_grpc import RuntimeStub
 from flwr.supercore.constant import ExecutorType
+from flwr.supercore.runtime import RuntimeHttpStub as CoreRuntimeHttpStub
 from flwr.supercore.version import package_version
+from flwr.superlink.runtime import RuntimeHttpStub as SuperLinkRuntimeHttpStub
 
 from .flower_superexec import _parse_args
 
@@ -63,6 +65,21 @@ def test_parse_superexec_accepts_kubernetes_executor_config() -> None:
     assert args.executor_config == "executor.yaml"
 
 
+def test_parse_superexec_accepts_http_api_flag() -> None:
+    """SuperExec should accept the temporary Runtime HTTP API flag."""
+    args = _parse_args().parse_args(
+        [
+            "--appio-api-address",
+            "127.0.0.1:8000",
+            "--plugin-type",
+            ExecPluginType.CLIENT_APP,
+            "--enable-http-api",
+        ]
+    )
+
+    assert args.enable_http_api is True
+
+
 def test_flower_superexec_checks_for_update(
     monkeypatch: pytest.MonkeyPatch,
 ) -> None:
@@ -117,6 +134,7 @@ def test_flower_superexec_clientapp_allows_missing_secret(
         health_server_address=None,
         runtime_dependency_install=False,
         executor=ExecutorType.SUBPROCESS,
+        enable_http_api=False,
     )
     captured: dict[str, object] = {}
 
@@ -137,7 +155,7 @@ def _run_superexec(**kwargs: object) -> None:
     monkeypatch.setattr(
         flower_superexec_module,
         "_get_plugin_and_stub_class",
-        lambda _plugin_type: (object, RuntimeStub),
+        lambda _plugin_type, _enable_http_api: (object, RuntimeStub),
     )
     monkeypatch.setattr(flower_superexec_module, "run_superexec", _run_superexec)
 
@@ -161,6 +179,7 @@ def test_flower_superexec_serverapp_allows_missing_secret(
         health_server_address=None,
         runtime_dependency_install=False,
         executor=ExecutorType.SUBPROCESS,
+        enable_http_api=False,
     )
 
     class _Parser:
@@ -182,7 +201,7 @@ def _run_superexec(**kwargs: object) -> None:
     monkeypatch.setattr(
         flower_superexec_module,
         "_get_plugin_and_stub_class",
-        lambda _plugin_type: (object, RuntimeStub),
+        lambda _plugin_type, _enable_http_api: (object, RuntimeStub),
     )
     monkeypatch.setattr(flower_superexec_module, "run_superexec", _run_superexec)
 
@@ -206,6 +225,7 @@ def test_flower_superexec_passes_executor_to_run_superexec(
         health_server_address=None,
         runtime_dependency_install=False,
         executor=ExecutorType.SUBPROCESS,
+        enable_http_api=False,
     )
     parser = Mock()
     parser.parse_args.return_value = args
@@ -222,7 +242,7 @@ def test_flower_superexec_passes_executor_to_run_superexec(
     monkeypatch.setattr(
         flower_superexec_module,
         "_get_plugin_and_stub_class",
-        lambda _plugin_type: (object, RuntimeStub),
+        lambda _plugin_type, _enable_http_api: (object, RuntimeStub),
     )
     monkeypatch.setattr(flower_superexec_module, "run_superexec", run_superexec_mock)
 
@@ -233,3 +253,22 @@ def test_flower_superexec_passes_executor_to_run_superexec(
         run_superexec_mock.call_args.kwargs["executor_type"] == ExecutorType.SUBPROCESS
     )
     assert run_superexec_mock.call_args.kwargs["executor_config"] is None
+
+
+@pytest.mark.parametrize(
+    ("plugin_type", "expected_stub"),
+    [
+        (ExecPluginType.CLIENT_APP, CoreRuntimeHttpStub),
+        (ExecPluginType.SERVER_APP, SuperLinkRuntimeHttpStub),
+        (ExecPluginType.SERVER_APP_EPHEMERAL, SuperLinkRuntimeHttpStub),
+    ],
+)
+def test_get_plugin_and_stub_class_selects_http_stub(
+    plugin_type: str, expected_stub: type[object]
+) -> None:
+    """HTTP mode should select the Runtime stub for each plugin surface."""
+    _, stub_class = flower_superexec_module._get_plugin_and_stub_class(
+        plugin_type, enable_http_api=True
+    )
+
+    assert stub_class is expected_stub
diff --git a/framework/py/flwr/supercore/heartbeat.py b/framework/py/flwr/supercore/heartbeat.py
index 82f64e1193e1..067fa30a9ec0 100644
--- a/framework/py/flwr/supercore/heartbeat.py
+++ b/framework/py/flwr/supercore/heartbeat.py
@@ -21,6 +21,7 @@
 from collections.abc import Callable
 
 import grpc
+import httpx
 
 from flwr.common.constant import (
     HEARTBEAT_BASE_MULTIPLIER,
@@ -33,6 +34,7 @@
 from flwr.proto.runtime_pb2 import SendTaskHeartbeatRequest
 from flwr.proto.runtime_pb2_grpc import RuntimeStub
 from flwr.supercore.retry import RetryInvoker, exponential
+from flwr.supercore.runtime import RuntimeHttpStub
 
 # pylint: enable=E0611
 
@@ -154,3 +156,22 @@ def fn() -> bool:
         return True
 
     return fn
+
+
+def make_task_heartbeat_fn_http(
+    stub: RuntimeHttpStub,
+) -> Callable[[], bool]:
+    """Get the function to send a heartbeat to an HTTP Runtime endpoint."""
+    req = SendTaskHeartbeatRequest()
+
+    def fn() -> bool:
+        try:
+            res = stub.SendTaskHeartbeat(req)
+        except httpx.TransportError:
+            return False
+
+        if not res.success:
+            signal.raise_signal(signal.SIGINT)
+        return True
+
+    return fn
diff --git a/framework/py/flwr/supercore/heartbeat_test.py b/framework/py/flwr/supercore/heartbeat_test.py
index 0cfec7f4cb4f..8b1ac1a91d29 100644
--- a/framework/py/flwr/supercore/heartbeat_test.py
+++ b/framework/py/flwr/supercore/heartbeat_test.py
@@ -19,7 +19,11 @@
 import unittest
 from unittest.mock import Mock
 
-from .heartbeat import HeartbeatSender
+import httpx
+
+from flwr.proto.runtime_pb2 import SendTaskHeartbeatResponse  # pylint: disable=E0611
+
+from .heartbeat import HeartbeatSender, make_task_heartbeat_fn_http
 
 
 # pylint: disable=protected-access
@@ -90,3 +94,19 @@ def test_heartbeat_fail_and_retry(self) -> None:
     def test_thread_is_daemon(self) -> None:
         """Test that the thread is a daemon thread."""
         self.assertTrue(self.heartbeat_sender._thread.daemon)
+
+
+def test_http_heartbeat_returns_true_on_success() -> None:
+    """HTTP heartbeat should report a successful Runtime response."""
+    stub = Mock()
+    stub.SendTaskHeartbeat.return_value = SendTaskHeartbeatResponse(success=True)
+
+    assert make_task_heartbeat_fn_http(stub)() is True
+
+
+def test_http_heartbeat_retries_transport_errors() -> None:
+    """HTTP heartbeat should make transport failures retryable."""
+    stub = Mock()
+    stub.SendTaskHeartbeat.side_effect = httpx.ConnectError("connection failed")
+
+    assert make_task_heartbeat_fn_http(stub)() is False
diff --git a/framework/py/flwr/supercore/superexec/executor/kubernetes_executor.py b/framework/py/flwr/supercore/superexec/executor/kubernetes_executor.py
index f77b47e4fead..014d2cac6cb1 100644
--- a/framework/py/flwr/supercore/superexec/executor/kubernetes_executor.py
+++ b/framework/py/flwr/supercore/superexec/executor/kubernetes_executor.py
@@ -517,6 +517,8 @@ def _taskexecutor_args(
         "--token-file",
         APPIO_TOKEN_FILE_PATH,
     ]
+    if spec.enable_http_api:
+        args.append("--enable-http-api")
 
     if spec.insecure:
         args.append("--insecure")
diff --git a/framework/py/flwr/supercore/superexec/executor/kubernetes_executor_test.py b/framework/py/flwr/supercore/superexec/executor/kubernetes_executor_test.py
index 0f2599a3ee60..186f2d12e036 100644
--- a/framework/py/flwr/supercore/superexec/executor/kubernetes_executor_test.py
+++ b/framework/py/flwr/supercore/superexec/executor/kubernetes_executor_test.py
@@ -407,6 +407,20 @@ def test_build_taskexecutor_pod_supports_clientapp_insecure_args() -> None:
     ]
 
 
+def test_build_taskexecutor_pod_forwards_http_api_flag() -> None:
+    """Test Pod construction forwards Runtime HTTP mode."""
+    pod = _as_dict(
+        _build_taskexecutor_pod(
+            _execution_spec(enable_http_api=True),
+            _executor_config(runtime_root_certificates=None),
+            None,
+            _LAUNCH_ATTEMPT_ID,
+        )
+    )
+
+    assert "--enable-http-api" in pod["spec"]["containers"][0]["args"]
+
+
 def test_build_taskexecutor_pod_supports_secure_default_trust_store() -> None:
     """Test secure Pod args can rely on container default trust store."""
     spec = _execution_spec()
diff --git a/framework/py/flwr/supercore/superexec/executor/subprocess_executor.py b/framework/py/flwr/supercore/superexec/executor/subprocess_executor.py
index 6e9e6f1d132b..50c51fd0b507 100644
--- a/framework/py/flwr/supercore/superexec/executor/subprocess_executor.py
+++ b/framework/py/flwr/supercore/superexec/executor/subprocess_executor.py
@@ -40,6 +40,8 @@ def launch(self, spec: ExecutionSpec) -> LaunchResult:
             "--token",
             spec.token,
         ]
+        if spec.enable_http_api:
+            args.append("--enable-http-api")
 
         if spec.insecure:
             args.append("--insecure")
diff --git a/framework/py/flwr/supercore/superexec/executor/subprocess_executor_test.py b/framework/py/flwr/supercore/superexec/executor/subprocess_executor_test.py
index 83377689664a..82bdf4668c93 100644
--- a/framework/py/flwr/supercore/superexec/executor/subprocess_executor_test.py
+++ b/framework/py/flwr/supercore/superexec/executor/subprocess_executor_test.py
@@ -93,6 +93,14 @@ def test_launch_renders_runtime_dependency_install_flag() -> None:
     assert "--allow-runtime-dependency-installation" in popen_mock.call_args.args[0]
 
 
+def test_launch_renders_http_api_flag() -> None:
+    """Test subprocess executor forwards Runtime HTTP mode."""
+    with patch.object(subprocess, "Popen") as popen_mock:
+        SubprocessExecutor().launch(_execution_spec(enable_http_api=True))
+
+    assert "--enable-http-api" in popen_mock.call_args.args[0]
+
+
 def test_launch_renders_parent_pid_flag() -> None:
     """Test subprocess executor renders subprocess parent PID flag."""
     with patch.object(subprocess, "Popen") as popen_mock:
diff --git a/framework/py/flwr/supercore/superexec/executor/types.py b/framework/py/flwr/supercore/superexec/executor/types.py
index ea10daa3d917..a23d0d9fc47b 100644
--- a/framework/py/flwr/supercore/superexec/executor/types.py
+++ b/framework/py/flwr/supercore/superexec/executor/types.py
@@ -36,6 +36,7 @@ class ExecutionSpec:  # pylint: disable=too-many-instance-attributes
     parent_pid: int | None
     suppress_output: bool
     task_id: int
+    enable_http_api: bool = False
 
     def __post_init__(self) -> None:
         """Validate fields required by all executors."""
diff --git a/framework/py/flwr/supercore/superexec/plugin/base_ephemeral_exec_plugin.py b/framework/py/flwr/supercore/superexec/plugin/base_ephemeral_exec_plugin.py
index 454ef803e656..97afe13c94b6 100644
--- a/framework/py/flwr/supercore/superexec/plugin/base_ephemeral_exec_plugin.py
+++ b/framework/py/flwr/supercore/superexec/plugin/base_ephemeral_exec_plugin.py
@@ -57,6 +57,8 @@ def launch_task(self, token: str, task: Task) -> None:  # type: ignore[override]
         elif self.root_certificates_path:
             cmds += ["--root-certificates", self.root_certificates_path]
         cmds += [self.runtime_api_address_arg, self.runtime_api_address]
+        if self.enable_http_api:
+            cmds += ["--enable-http-api"]
         cmds += ["--token", token]
         cmds += ["--parent-pid", str(os.getpid())]
         if self.runtime_dependency_install:
diff --git a/framework/py/flwr/supercore/superexec/plugin/base_ephemeral_exec_plugin_test.py b/framework/py/flwr/supercore/superexec/plugin/base_ephemeral_exec_plugin_test.py
index 942c3ee117ba..fc4b8126d10c 100644
--- a/framework/py/flwr/supercore/superexec/plugin/base_ephemeral_exec_plugin_test.py
+++ b/framework/py/flwr/supercore/superexec/plugin/base_ephemeral_exec_plugin_test.py
@@ -42,12 +42,13 @@ class _EphemeralExecPlugin(BaseEphemeralExecPlugin):
     runtime_api_address_arg = "--serverappio-api-address"
 
 
-def _get_ephemeral_plugin() -> _EphemeralExecPlugin:
+def _get_ephemeral_plugin(*, enable_http_api: bool = False) -> _EphemeralExecPlugin:
     return _EphemeralExecPlugin(
         runtime_api_address="127.0.0.1:9091",
         get_run=_get_run,
         insecure=True,
         root_certificates_path=None,
+        enable_http_api=enable_http_api,
     )
 
 
@@ -119,3 +120,18 @@ def test_launch_task_calls_cleanup_before_launch() -> None:
 
     # Assert
     assert call_log == ["cleanup", "subprocess"]
+
+
+def test_launch_task_forwards_http_api_flag() -> None:
+    """Launch should forward Runtime HTTP mode to the app process."""
+    plugin = _get_ephemeral_plugin(enable_http_api=True)
+
+    with (
+        patch(
+            "flwr.supercore.superexec.plugin.base_ephemeral_exec_plugin.subprocess.run"
+        ) as run,
+        patch("flwr.supercore.superexec.plugin.base_ephemeral_exec_plugin.flwr_exit"),
+    ):
+        plugin.launch_task(token="token-123", task=_get_task(task_id=5))
+
+    assert "--enable-http-api" in run.call_args.args[0]
diff --git a/framework/py/flwr/supercore/superexec/plugin/base_exec_plugin.py b/framework/py/flwr/supercore/superexec/plugin/base_exec_plugin.py
index d9a1ccb67be6..0e503b07950e 100644
--- a/framework/py/flwr/supercore/superexec/plugin/base_exec_plugin.py
+++ b/framework/py/flwr/supercore/superexec/plugin/base_exec_plugin.py
@@ -49,6 +49,7 @@ def __init__(  # pylint: disable=R0913, R0917
         runtime_dependency_install: bool = RUNTIME_DEPENDENCY_INSTALL,
         *,
         executor: Executor,
+        enable_http_api: bool = False,
     ) -> None:
         super().__init__(
             runtime_api_address=runtime_api_address,
@@ -57,6 +58,7 @@ def __init__(  # pylint: disable=R0913, R0917
             get_run=get_run,
             runtime_dependency_install=runtime_dependency_install,
             executor=executor,
+            enable_http_api=enable_http_api,
         )
         self.executor: Executor = executor
 
@@ -103,6 +105,7 @@ def _build_execution_spec(
                 self.suppress_output and task_type not in self.visible_output_task_types
             ),
             task_id=task_id,
+            enable_http_api=self.enable_http_api,
         )
 
     def _get_supported_task_type(self, task: Task) -> TaskType | None:
diff --git a/framework/py/flwr/supercore/superexec/plugin/base_exec_plugin_test.py b/framework/py/flwr/supercore/superexec/plugin/base_exec_plugin_test.py
index 525c8765f1ce..3b04dcd71682 100644
--- a/framework/py/flwr/supercore/superexec/plugin/base_exec_plugin_test.py
+++ b/framework/py/flwr/supercore/superexec/plugin/base_exec_plugin_test.py
@@ -159,6 +159,23 @@ def test_launch_task_forwards_runtime_dependency_install_flag() -> None:
     assert spec.task_id == 7
 
 
+def test_launch_task_forwards_http_api_flag() -> None:
+    """Ensure execution spec forwards Runtime HTTP mode."""
+    executor = Mock()
+    plugin = DummyExecPlugin(
+        runtime_api_address="127.0.0.1:8000",
+        insecure=True,
+        root_certificates_path=None,
+        get_run=Mock(),
+        executor=executor,
+        enable_http_api=True,
+    )
+
+    plugin.launch_task(token="token-123", task=_get_task(task_id=7))
+
+    assert _execution_spec_from_executor(executor).enable_http_api is True
+
+
 def test_launch_task_skips_optional_runtime_flags_by_default() -> None:
     """Ensure execution spec omits optional runtime install flags by default."""
     executor = Mock()
diff --git a/framework/py/flwr/supercore/superexec/plugin/exec_plugin.py b/framework/py/flwr/supercore/superexec/plugin/exec_plugin.py
index 1681065dc2a0..023a2a6d159d 100644
--- a/framework/py/flwr/supercore/superexec/plugin/exec_plugin.py
+++ b/framework/py/flwr/supercore/superexec/plugin/exec_plugin.py
@@ -36,6 +36,7 @@ def __init__(  # pylint: disable=R0913, R0917
         get_run: Callable[[int], Run],
         runtime_dependency_install: bool = RUNTIME_DEPENDENCY_INSTALL,
         executor: Executor | None = None,
+        enable_http_api: bool = False,
     ) -> None:
         self.runtime_api_address = runtime_api_address
         self.insecure = insecure
@@ -44,6 +45,7 @@ def __init__(  # pylint: disable=R0913, R0917
         self.runtime_dependency_install = runtime_dependency_install
         # Non-ephemeral plugins use the executor to start task processes.
         self.executor = executor
+        self.enable_http_api = enable_http_api
 
     @abstractmethod
     def select_run_id(self, candidate_run_ids: Sequence[int]) -> int | None:
diff --git a/framework/py/flwr/supercore/superexec/run_superexec.py b/framework/py/flwr/supercore/superexec/run_superexec.py
index 2c0c1ee975c8..56a1df469707 100644
--- a/framework/py/flwr/supercore/superexec/run_superexec.py
+++ b/framework/py/flwr/supercore/superexec/run_superexec.py
@@ -16,8 +16,9 @@
 
 
 import time
+from collections.abc import Callable
 from logging import ERROR, WARNING
-from typing import Any
+from typing import Any, cast
 
 import grpc
 
@@ -38,13 +39,17 @@
 from flwr.supercore.grpc_health import run_health_server_grpc_no_tls
 from flwr.supercore.interceptors import (
     RuntimeVersionClientInterceptor,
+    RuntimeVersionHttpInterceptor,
     SuperExecAuthClientInterceptor,
+    SuperExecAuthHttpInterceptor,
 )
 from flwr.supercore.interceptors.superexec_auth_interceptor import (
     RUNTIME_SUPEREXEC_METHODS,
 )
+from flwr.supercore.protobuf.client import ProtobufClient, ProtobufClientInterceptor
 from flwr.supercore.retry import make_simple_grpc_retry_invoker, wrap_stub
 from flwr.supercore.run import Run
+from flwr.supercore.runtime import RuntimeHttpStub
 from flwr.supercore.telemetry import EventType
 from flwr.supercore.tls import validate_and_resolve_root_certificates
 
@@ -103,7 +108,7 @@ def _handle_launch_result(result: LaunchResult | None, task: Task) -> None:
 
 def run_superexec(  # pylint: disable=R0912,R0913,R0914,R0915,R0917
     plugin_class: type[ExecPlugin],
-    stub_class: type[RuntimeStub],
+    stub_class: type[RuntimeStub] | type[RuntimeHttpStub],
     runtime_api_address: str,
     insecure: bool,
     root_certificates_path: str | None = None,
@@ -114,6 +119,7 @@ def run_superexec(  # pylint: disable=R0912,R0913,R0914,R0915,R0917
     runtime_dependency_install: bool = RUNTIME_DEPENDENCY_INSTALL,
     executor_type: ExecutorType = ExecutorType.SUBPROCESS,
     executor_config: ExecutorConfig | None = None,
+    enable_http_api: bool = False,
 ) -> None:
     """Run Flower SuperExec.
 
@@ -147,22 +153,62 @@ def run_superexec(  # pylint: disable=R0912,R0913,R0914,R0915,R0917
         The executor to use for non-ephemeral app processes.
     executor_config : Optional[ExecutorConfig] (default: None)
         Parsed executor configuration.
+    enable_http_api : bool (default: False)
+        Whether to connect to the Runtime API over HTTP instead of gRPC.
     """
     try:
         executor = get_executor(executor_type, executor_config=executor_config)
     except ValueError as err:
         flwr_exit(ExitCode.SUPEREXEC_INVALID_EXECUTOR_CONFIG, str(err))
 
-    interceptors: list[grpc.UnaryUnaryClientInterceptor] = [
-        RuntimeVersionClientInterceptor(component_name="SuperExec")
-    ]
-    auth_interceptor: SuperExecAuthClientInterceptor | None = None
-    if superexec_auth_secret:
-        auth_interceptor = SuperExecAuthClientInterceptor(
-            master_secret=superexec_auth_secret,
-            protected_methods=RUNTIME_SUPEREXEC_METHODS,
+    auth_interceptor: (
+        SuperExecAuthClientInterceptor | SuperExecAuthHttpInterceptor | None
+    ) = None
+    close_runtime_connection: Callable[[], None]
+    stub: RuntimeStub | RuntimeHttpStub
+    if enable_http_api:
+        http_interceptors: list[ProtobufClientInterceptor] = [
+            RuntimeVersionHttpInterceptor(component_name="SuperExec")
+        ]
+        if superexec_auth_secret:
+            auth_interceptor = SuperExecAuthHttpInterceptor(
+                master_secret=superexec_auth_secret,
+                protected_methods=RUNTIME_SUPEREXEC_METHODS,
+            )
+            http_interceptors.append(auth_interceptor)
+        validate_and_resolve_root_certificates(root_certificates_path, insecure)
+        http_stub_class = cast(type[RuntimeHttpStub], stub_class)
+        scheme = "http" if insecure else "https"
+        stub = http_stub_class(
+            f"{scheme}://{runtime_api_address}",
+            interceptors=http_interceptors,
+            verify=False if insecure else root_certificates_path or True,
         )
-        interceptors.append(auth_interceptor)
+        close_runtime_connection = cast(ProtobufClient, stub).close
+    else:
+        grpc_interceptors: list[grpc.UnaryUnaryClientInterceptor] = [
+            RuntimeVersionClientInterceptor(component_name="SuperExec")
+        ]
+        if superexec_auth_secret:
+            auth_interceptor = SuperExecAuthClientInterceptor(
+                master_secret=superexec_auth_secret,
+                protected_methods=RUNTIME_SUPEREXEC_METHODS,
+            )
+            grpc_interceptors.append(auth_interceptor)
+
+        channel = create_channel(
+            server_address=runtime_api_address,
+            insecure=insecure,
+            root_certificates=validate_and_resolve_root_certificates(
+                root_certificates_path, insecure
+            ),
+            interceptors=grpc_interceptors,
+        )
+        channel.subscribe(on_channel_state_change)
+        grpc_stub_class = cast(type[RuntimeStub], stub_class)
+        stub = grpc_stub_class(channel)
+        wrap_stub(stub, make_simple_grpc_retry_invoker())
+        close_runtime_connection = channel.close
 
     # Start monitoring the parent process if a PID is provided
     if parent_pid is not None:
@@ -174,29 +220,14 @@ def run_superexec(  # pylint: disable=R0912,R0913,R0914,R0915,R0917
         health_server = run_health_server_grpc_no_tls(health_server_address)
         grpc_servers.append(health_server)
 
-    # Create the channel to the Runtime API
-    channel = create_channel(
-        server_address=runtime_api_address,
-        insecure=insecure,
-        root_certificates=validate_and_resolve_root_certificates(
-            root_certificates_path, insecure
-        ),
-        interceptors=interceptors,
-    )
-    channel.subscribe(on_channel_state_change)
-
-    # Register exit handlers to close the channel on exit
+    # Register exit handlers to close the Runtime API connection on exit
     register_signal_handlers(
         event_type=EventType.RUN_SUPEREXEC_LEAVE,
         exit_message="SuperExec terminated gracefully.",
         grpc_servers=grpc_servers,
-        exit_handlers=[lambda: channel.close()],  # pylint: disable=W0108
+        exit_handlers=[close_runtime_connection],
     )
 
-    # Create the gRPC stub for the Runtime API
-    stub = stub_class(channel)
-    wrap_stub(stub, make_simple_grpc_retry_invoker())
-
     def get_run(run_id: int) -> Run:
         _req = GetRunRequest(run_id=run_id)
         _res = stub.GetRun(_req)
@@ -210,6 +241,7 @@ def get_run(run_id: int) -> Run:
         get_run=get_run,
         runtime_dependency_install=runtime_dependency_install,
         executor=executor,
+        enable_http_api=enable_http_api,
     )
 
     # Load plugin configuration from file if provided
@@ -263,4 +295,4 @@ def cleanup_auth_secret() -> None:
             # Sleep for a while before checking again
             time.sleep(1)
     finally:
-        channel.close()
+        close_runtime_connection()
diff --git a/framework/py/flwr/supercore/superexec/run_superexec_test.py b/framework/py/flwr/supercore/superexec/run_superexec_test.py
index 183fd7586d66..dc80b266082d 100644
--- a/framework/py/flwr/supercore/superexec/run_superexec_test.py
+++ b/framework/py/flwr/supercore/superexec/run_superexec_test.py
@@ -24,7 +24,9 @@
 from flwr.supercore.constant import ExecutorType
 from flwr.supercore.interceptors import (
     RuntimeVersionClientInterceptor,
+    RuntimeVersionHttpInterceptor,
     SuperExecAuthClientInterceptor,
+    SuperExecAuthHttpInterceptor,
 )
 from flwr.supercore.superexec.executor import LaunchResult, LaunchResultStatus
 
@@ -112,6 +114,53 @@ def _create_channel(**kwargs: Any) -> Mock:
     )
 
 
+@pytest.mark.parametrize(
+    ("superexec_auth_secret", "expected_interceptor_types"),
+    [
+        (None, (RuntimeVersionHttpInterceptor,)),
+        (
+            b"superexec-secret",
+            (RuntimeVersionHttpInterceptor, SuperExecAuthHttpInterceptor),
+        ),
+    ],
+)
+def test_run_superexec_configures_http_runtime_stub(
+    monkeypatch: pytest.MonkeyPatch,
+    superexec_auth_secret: bytes | None,
+    expected_interceptor_types: tuple[type[object], ...],
+) -> None:
+    """SuperExec should create an HTTP stub with version and auth interceptors."""
+    stub = Mock()
+    stub.PullPendingTasks.side_effect = KeyboardInterrupt()
+    stub_class = Mock(return_value=stub)
+    create_channel = Mock()
+
+    monkeypatch.setattr(run_superexec_module, "create_channel", create_channel)
+    monkeypatch.setattr(run_superexec_module, "register_signal_handlers", Mock())
+
+    with pytest.raises(KeyboardInterrupt):
+        run_superexec_module.run_superexec(
+            plugin_class=Mock(),
+            stub_class=stub_class,
+            runtime_api_address="127.0.0.1:8000",
+            insecure=True,
+            superexec_auth_secret=superexec_auth_secret,
+            enable_http_api=True,
+        )
+
+    create_channel.assert_not_called()
+    assert stub_class.call_args.args == ("http://127.0.0.1:8000",)
+    assert stub_class.call_args.kwargs["verify"] is False
+    assert (
+        tuple(
+            type(interceptor)
+            for interceptor in stub_class.call_args.kwargs["interceptors"]
+        )
+        == expected_interceptor_types
+    )
+    stub.close.assert_called_once_with()
+
+
 def test_run_superexec_passes_executor_config_to_factory(
     monkeypatch: pytest.MonkeyPatch,
 ) -> None:
diff --git a/framework/py/flwr/supernode/cli/flower_supernode.py b/framework/py/flwr/supernode/cli/flower_supernode.py
index bfeb1f291568..942c3a17db74 100644
--- a/framework/py/flwr/supernode/cli/flower_supernode.py
+++ b/framework/py/flwr/supernode/cli/flower_supernode.py
@@ -204,6 +204,9 @@ def flower_supernode() -> None:
             trusted_entities=config.trusted_entities,
             superexec_auth_secret=config.superexec_auth_secret,
             runtime_dependency_install=config.runtime_dependency_install,
+            runtime_http_api_address=(
+                f"{config.host}:{config.port}" if config.enable_http_api else None
+            ),
         )
     finally:
         if http_server is not None and http_thread is not None:
diff --git a/framework/py/flwr/supernode/cli/flower_supernode_test.py b/framework/py/flwr/supernode/cli/flower_supernode_test.py
index fe49d0d2cc3a..422e88eec4dd 100644
--- a/framework/py/flwr/supernode/cli/flower_supernode_test.py
+++ b/framework/py/flwr/supernode/cli/flower_supernode_test.py
@@ -224,6 +224,8 @@ def test_flower_supernode_injects_state_factory_and_manages_http_api(
     """SuperNode should share state and stop its background HTTP API."""
     config = Mock()
     config.enable_http_api = True
+    config.host = "127.0.0.1"
+    config.port = 8000
     objectstore_factory = Mock()
     state_factory = Mock()
     start_client_internal = Mock()
@@ -258,6 +260,10 @@ def test_flower_supernode_injects_state_factory_and_manages_http_api(
 
     node_state_factory.assert_called_once_with(objectstore_factory=objectstore_factory)
     assert start_client_internal.call_args.kwargs["state_factory"] is state_factory
+    assert (
+        start_client_internal.call_args.kwargs["runtime_http_api_address"]
+        == "127.0.0.1:8000"
+    )
     start_http_api.assert_called_once_with(config, state_factory)
     assert http_server.should_exit is True
     http_thread.join.assert_called_once_with()
diff --git a/framework/py/flwr/supernode/cli/flwr_clientapp.py b/framework/py/flwr/supernode/cli/flwr_clientapp.py
index 3136cb4a95c3..aa0dfac5860c 100644
--- a/framework/py/flwr/supernode/cli/flwr_clientapp.py
+++ b/framework/py/flwr/supernode/cli/flwr_clientapp.py
@@ -48,6 +48,8 @@ def flwr_clientapp() -> None:
         ),
         parent_pid=args.parent_pid,
         runtime_dependency_install=args.runtime_dependency_install,
+        enable_http_api=args.enable_http_api,
+        root_certificates_path=args.root_certificates,
     )
 
 
@@ -64,5 +66,11 @@ def _parse_args_run_flwr_clientapp() -> argparse.ArgumentParser:
         help="Address of SuperNode's Runtime API (IPv4, IPv6, or a domain name)."
         f"By default, it is set to {SUPERNODE_RUNTIME_API_DEFAULT_CLIENT_ADDRESS}.",
     )
+    parser.add_argument(
+        "--enable-http-api",
+        action="store_true",
+        default=False,
+        help="EXPERIMENTAL: Connect to the Runtime API over HTTP instead of gRPC.",
+    )
     add_args_flwr_app_common(parser=parser)
     return parser
diff --git a/framework/py/flwr/supernode/cli/flwr_clientapp_test.py b/framework/py/flwr/supernode/cli/flwr_clientapp_test.py
index 7688b09e51a7..c9a509e35144 100644
--- a/framework/py/flwr/supernode/cli/flwr_clientapp_test.py
+++ b/framework/py/flwr/supernode/cli/flwr_clientapp_test.py
@@ -52,6 +52,7 @@ def test_parse_flwr_clientapp_parses_tokenized_invocation() -> None:
             "--parent-pid",
             "1234",
             "--allow-runtime-dependency-installation",
+            "--enable-http-api",
         ]
     )
 
@@ -60,6 +61,7 @@ def test_parse_flwr_clientapp_parses_tokenized_invocation() -> None:
     assert args.insecure is True
     assert args.parent_pid == 1234
     assert args.runtime_dependency_install is True
+    assert args.enable_http_api is True
 
 
 def test_flwr_clientapp_forwards_cli_args() -> None:
@@ -71,6 +73,7 @@ def test_flwr_clientapp_forwards_cli_args() -> None:
         root_certificates=None,
         parent_pid=321,
         runtime_dependency_install=True,
+        enable_http_api=True,
     )
 
     class _Parser:
@@ -93,3 +96,5 @@ def parse_args(self) -> SimpleNamespace:
     assert kwargs["certificates"] is None
     assert kwargs["parent_pid"] == 321
     assert kwargs["runtime_dependency_install"] is True
+    assert kwargs["enable_http_api"] is True
+    assert kwargs["root_certificates_path"] is None
diff --git a/framework/py/flwr/supernode/runtime/run_clientapp.py b/framework/py/flwr/supernode/runtime/run_clientapp.py
index fe0f0ec3086c..66fc395701ba 100644
--- a/framework/py/flwr/supernode/runtime/run_clientapp.py
+++ b/framework/py/flwr/supernode/runtime/run_clientapp.py
@@ -18,6 +18,7 @@
 from logging import DEBUG, ERROR
 
 import grpc
+import httpx
 
 from flwr.app import Context, Message
 from flwr.app.error import Error
@@ -49,7 +50,11 @@
 from flwr.supercore.exit import ExitCode, flwr_exit, register_signal_handlers
 from flwr.supercore.fab import Fab
 from flwr.supercore.grpc import create_channel, on_channel_state_change
-from flwr.supercore.heartbeat import HeartbeatSender, make_task_heartbeat_fn_grpc
+from flwr.supercore.heartbeat import (
+    HeartbeatSender,
+    make_task_heartbeat_fn_grpc,
+    make_task_heartbeat_fn_http,
+)
 from flwr.supercore.inflatable.inflatable_object import (
     get_all_nested_objects,
     get_object_tree,
@@ -66,10 +71,14 @@
 )
 from flwr.supercore.interceptors import (
     RuntimeTokenClientInterceptor,
+    RuntimeTokenHttpInterceptor,
     RuntimeVersionClientInterceptor,
+    RuntimeVersionHttpInterceptor,
 )
+from flwr.supercore.protobuf.client import ProtobufClientInterceptor
 from flwr.supercore.retry import make_simple_grpc_retry_invoker, wrap_stub
 from flwr.supercore.run import Run
+from flwr.supercore.runtime import RuntimeHttpStub
 from flwr.supercore.superexec.dependency_installer import (
     RuntimeDependencyInstallationError,
     cleanup_app_runtime_environment,
@@ -78,13 +87,15 @@
 from flwr.supercore.telemetry import EventType, event
 
 
-def run_clientapp(  # pylint: disable=R0913, R0914, R0915, R0917
+def run_clientapp(  # pylint: disable=R0912, R0913, R0914, R0915, R0917
     runtime_api_address: str,
     token: str,
     insecure: bool,
     certificates: bytes | None = None,
     parent_pid: int | None = None,
     runtime_dependency_install: bool = RUNTIME_DEPENDENCY_INSTALL,
+    enable_http_api: bool = False,
+    root_certificates_path: str | None = None,
 ) -> None:
     """Run Flower ClientApp process."""
     # Monitor the main process in case of SIGKILL
@@ -93,19 +104,37 @@ def run_clientapp(  # pylint: disable=R0913, R0914, R0915, R0917
 
     event(EventType.FLWR_CLIENTAPP_RUN_ENTER)
 
-    channel = create_channel(
-        server_address=runtime_api_address,
-        insecure=insecure,
-        root_certificates=certificates,
-        interceptors=[
-            RuntimeVersionClientInterceptor(component_name="flwr-clientapp"),
-            RuntimeTokenClientInterceptor(token),
-        ],
-    )
-    channel.subscribe(on_channel_state_change)
-    stub = RuntimeStub(channel)
-    retry_invoker = make_simple_grpc_retry_invoker()
-    wrap_stub(stub, retry_invoker)
+    retry_invoker = None
+    stub: RuntimeStub | RuntimeHttpStub
+    if enable_http_api:
+        http_interceptors: list[ProtobufClientInterceptor] = [
+            RuntimeVersionHttpInterceptor(component_name="flwr-clientapp"),
+            RuntimeTokenHttpInterceptor(token),
+        ]
+        scheme = "http" if insecure else "https"
+        stub = RuntimeHttpStub(
+            f"{scheme}://{runtime_api_address}",
+            interceptors=http_interceptors,
+            verify=False if insecure else root_certificates_path or True,
+        )
+        close_runtime_connection = stub.close
+        heartbeat_fn = make_task_heartbeat_fn_http(stub)
+    else:
+        channel = create_channel(
+            server_address=runtime_api_address,
+            insecure=insecure,
+            root_certificates=certificates,
+            interceptors=[
+                RuntimeVersionClientInterceptor(component_name="flwr-clientapp"),
+                RuntimeTokenClientInterceptor(token),
+            ],
+        )
+        channel.subscribe(on_channel_state_change)
+        stub = RuntimeStub(channel)
+        retry_invoker = make_simple_grpc_retry_invoker()
+        wrap_stub(stub, retry_invoker)
+        close_runtime_connection = channel.close
+        heartbeat_fn = make_task_heartbeat_fn_grpc(stub)
 
     # Initialize variables for exit handler
     heartbeat_sender = None
@@ -119,7 +148,8 @@ def run_clientapp(  # pylint: disable=R0913, R0914, R0915, R0917
 
     def on_exit() -> None:
         # Set Grpc max retries to 1 to avoid blocking on exit
-        retry_invoker.max_tries = 1
+        if retry_invoker is not None:
+            retry_invoker.max_tries = 1
 
         # Push final status and context (if available)
         push_task_output(
@@ -132,7 +162,7 @@ def on_exit() -> None:
         # Stop heartbeat sender
         if heartbeat_sender is not None and heartbeat_sender.is_running:
             heartbeat_sender.stop()
-        channel.close()
+        close_runtime_connection()
 
         cleanup_app_runtime_environment(runtime_env_dir)
 
@@ -144,7 +174,7 @@ def on_exit() -> None:
 
     try:
         # Start task heartbeat
-        heartbeat_sender = HeartbeatSender(make_task_heartbeat_fn_grpc(stub))
+        heartbeat_sender = HeartbeatSender(heartbeat_fn)
         heartbeat_sender.start()
 
         # Pull Message, Context, Run and FAB from SuperNode
@@ -234,7 +264,9 @@ def on_exit() -> None:
     )
 
 
-def pull_task_input(stub: RuntimeStub) -> tuple[Message, Context, Run, Fab]:
+def pull_task_input(
+    stub: RuntimeStub | RuntimeHttpStub,
+) -> tuple[Message, Context, Run, Fab]:
     """Pull TaskInput from SuperNode."""
     # Pull Context, Run and FAB
     res: PullTaskInputResponse = stub.PullTaskInput(PullTaskInputRequest())
@@ -264,7 +296,9 @@ def pull_task_input(stub: RuntimeStub) -> tuple[Message, Context, Run, Fab]:
     return message, context, run, fab
 
 
-def push_message(stub: RuntimeStub, message: Message, context: Context) -> None:
+def push_message(
+    stub: RuntimeStub | RuntimeHttpStub, message: Message, context: Context
+) -> None:
     """Push reply message to SuperNode."""
     # Set message ID
     message.metadata.__dict__["_message_id"] = message.object_id
@@ -302,7 +336,7 @@ def push_message(stub: RuntimeStub, message: Message, context: Context) -> None:
 
 
 def push_task_output(  # pylint: disable=R0913, R0917
-    stub: RuntimeStub,
+    stub: RuntimeStub | RuntimeHttpStub,
     context: Context | None,
     sub_status: str,
     details: str,
@@ -317,5 +351,5 @@ def push_task_output(  # pylint: disable=R0913, R0917
                 details=details,
             )
         )
-    except grpc.RpcError as err:
+    except (grpc.RpcError, httpx.HTTPError) as err:
         log(ERROR, "Failed to push task output: %s", str(err))
diff --git a/framework/py/flwr/supernode/runtime/run_clientapp_test.py b/framework/py/flwr/supernode/runtime/run_clientapp_test.py
index 2e8f1219d00e..e98090f3b784 100644
--- a/framework/py/flwr/supernode/runtime/run_clientapp_test.py
+++ b/framework/py/flwr/supernode/runtime/run_clientapp_test.py
@@ -31,7 +31,9 @@
 from flwr.supercore.fab import Fab
 from flwr.supercore.interceptors import (
     RuntimeTokenClientInterceptor,
+    RuntimeTokenHttpInterceptor,
     RuntimeVersionClientInterceptor,
+    RuntimeVersionHttpInterceptor,
 )
 
 from .run_clientapp import pull_task_input, run_clientapp
@@ -74,6 +76,26 @@ def test_run_clientapp_adds_client_interceptors(self) -> None:
         # pylint: disable-next=protected-access
         self.assertEqual(interceptors[0]._metadata.component_name, "flwr-clientapp")
 
+    def test_run_clientapp_adds_http_interceptors(self) -> None:
+        """`run_clientapp` should configure its HTTP Runtime stub."""
+        with patch(
+            "flwr.supernode.runtime.run_clientapp.RuntimeHttpStub",
+            side_effect=RuntimeError,
+        ) as runtime_http_stub:
+            with self.assertRaises(RuntimeError):
+                run_clientapp(
+                    "127.0.0.1:8000",
+                    insecure=True,
+                    token="test-token",
+                    enable_http_api=True,
+                )
+
+        self.assertEqual(runtime_http_stub.call_args.args, ("http://127.0.0.1:8000",))
+        self.assertIs(runtime_http_stub.call_args.kwargs["verify"], False)
+        interceptors = runtime_http_stub.call_args.kwargs["interceptors"]
+        self.assertIsInstance(interceptors[0], RuntimeVersionHttpInterceptor)
+        self.assertIsInstance(interceptors[1], RuntimeTokenHttpInterceptor)
+
     def test_run_clientapp_exits_nonzero_on_grpc_error(self) -> None:
         """`run_clientapp` should not report success after Runtime API failures."""
         with (
diff --git a/framework/py/flwr/supernode/start_client_internal.py b/framework/py/flwr/supernode/start_client_internal.py
index 1bdd365bfd76..a52387591699 100644
--- a/framework/py/flwr/supernode/start_client_internal.py
+++ b/framework/py/flwr/supernode/start_client_internal.py
@@ -107,6 +107,7 @@ def start_client_internal(
     trusted_entities: dict[str, str] | None = None,
     superexec_auth_secret: bytes | None = None,
     runtime_dependency_install: bool = RUNTIME_DEPENDENCY_INSTALL,
+    runtime_http_api_address: str | None = None,
 ) -> None:
     """Start a Flower client node which connects to a Flower server.
 
@@ -171,6 +172,8 @@ def start_client_internal(
         Secret used by Runtime API SuperExec metadata auth.
     runtime_dependency_install : bool (default: False)
         Whether runtime dependency installation is allowed.
+    runtime_http_api_address : Optional[str] (default: None)
+        Runtime HTTP API address. When provided, SuperExec uses HTTP instead of gRPC.
     """
     if insecure is None:
         insecure = root_certificates is None
@@ -230,8 +233,14 @@ def start_client_internal(
     if isolation == ISOLATION_MODE_SUBPROCESS:
         # `bound_address` contains the actual address when the port is set to :0
         # which means let the OS choose a free port.
-        runtime_address = resolve_bind_address(runtime_server.bound_address)
+        runtime_address = (
+            runtime_http_api_address
+            if runtime_http_api_address is not None
+            else resolve_bind_address(runtime_server.bound_address)
+        )
         command = ["flower-superexec"]
+        if runtime_http_api_address is not None:
+            command += ["--enable-http-api"]
         command += get_client_tls_args(
             insecure=runtime_certificates is None,
             root_certificates_path=runtime_root_certificates_path,
diff --git a/framework/py/flwr/supernode/start_client_internal_test.py b/framework/py/flwr/supernode/start_client_internal_test.py
index 088c2c22168b..10ce7267845a 100644
--- a/framework/py/flwr/supernode/start_client_internal_test.py
+++ b/framework/py/flwr/supernode/start_client_internal_test.py
@@ -416,6 +416,7 @@ def _run_until_connection_start(
     runtime_root_certificates_path: str | None = None,
     runtime_api_address: str = "127.0.0.1:9094",
     bound_address: str = "127.0.0.1:9094",
+    runtime_http_api_address: str | None = None,
 ) -> tuple[Mock, Mock]:
     """Run startup only far enough to inspect Runtime API and SuperExec wiring."""
     objectstore_factory = Mock()
@@ -445,6 +446,7 @@ def _run_until_connection_start(
                 runtime_api_address=runtime_api_address,
                 runtime_certificates=runtime_certificates,
                 runtime_root_certificates_path=runtime_root_certificates_path,
+                runtime_http_api_address=runtime_http_api_address,
             )
 
     assert run_runtime.call_args.kwargs["state_factory"] is state_factory
@@ -497,3 +499,12 @@ def test_start_client_internal_launches_superexec_with_bound_runtime_address() -
 
     command = popen.call_args.args[0]
     assert command[command.index("--appio-api-address") + 1] == "localhost:54321"
+
+
+def test_start_client_internal_launches_http_superexec() -> None:
+    """Subprocess SuperExec should use the Runtime HTTP endpoint when enabled."""
+    _, popen = _run_until_connection_start(runtime_http_api_address="127.0.0.1:8000")
+
+    command = popen.call_args.args[0]
+    assert "--enable-http-api" in command
+    assert command[command.index("--appio-api-address") + 1] == "127.0.0.1:8000"