diff --git a/contexthub/aidl/default/Android.bp b/contexthub/aidl/default/Android.bp
index 2960746..da173f9 100644
--- a/contexthub/aidl/default/Android.bp
+++ b/contexthub/aidl/default/Android.bp
@@ -30,7 +30,7 @@
     shared_libs: [
         "libbase",
         "libbinder_ndk",
-        "android.hardware.contexthub-V3-ndk",
+        "android.hardware.contexthub-V4-ndk",
     ],
     export_include_dirs: ["include"],
     srcs: [
@@ -51,7 +51,7 @@
     shared_libs: [
         "libbase",
         "libbinder_ndk",
-        "android.hardware.contexthub-V3-ndk",
+        "android.hardware.contexthub-V4-ndk",
     ],
     static_libs: [
         "libcontexthubexampleimpl",
diff --git a/contexthub/aidl/default/ContextHub.cpp b/contexthub/aidl/default/ContextHub.cpp
index bd483d7..5713a1b 100644
--- a/contexthub/aidl/default/ContextHub.cpp
+++ b/contexthub/aidl/default/ContextHub.cpp
@@ -136,4 +136,83 @@
     return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
+ScopedAStatus ContextHub::getHubs(std::vector<HubInfo>* _aidl_return) {
+    ContextHubInfo hub = {};
+    hub.name = "Mock Context Hub";
+    hub.vendor = "AOSP";
+    hub.toolchain = "n/a";
+    hub.id = kMockHubId;
+    hub.peakMips = 1;
+    hub.maxSupportedMessageLengthBytes = 4096;
+    hub.chrePlatformId = UINT64_C(0x476f6f6754000000);
+    hub.chreApiMajorVersion = 1;
+    hub.chreApiMinorVersion = 6;
+    hub.supportsReliableMessages = false;
+
+    HubInfo hubInfo1 = {};
+    hubInfo1.hubId = hub.chrePlatformId;
+    hubInfo1.hubDetails = HubInfo::HubDetails::make<HubInfo::HubDetails::Tag::contextHubInfo>(hub);
+
+    VendorHubInfo vendorHub = {};
+    vendorHub.name = "Mock Vendor Hub";
+    vendorHub.version = 42;
+
+    HubInfo hubInfo2 = {};
+    hubInfo1.hubId = UINT64_C(0x1234567812345678);
+    hubInfo1.hubDetails =
+            HubInfo::HubDetails::make<HubInfo::HubDetails::Tag::vendorHubInfo>(vendorHub);
+
+    _aidl_return->push_back(hubInfo1);
+    _aidl_return->push_back(hubInfo2);
+
+    return ScopedAStatus::ok();
+};
+
+ScopedAStatus ContextHub::getEndpoints(std::vector<EndpointInfo>* /* _aidl_return */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::registerEndpoint(const EndpointInfo& /* in_endpoint */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::unregisterEndpoint(const EndpointInfo& /* in_endpoint */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::registerEndpointCallback(
+        const std::shared_ptr<IEndpointCallback>& /* in_callback */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::requestSessionIdRange(int32_t /* in_size */,
+                                                std::vector<int32_t>* /* _aidl_return */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::openEndpointSession(
+        int32_t /* in_sessionId */, const EndpointId& /* in_destination */,
+        const EndpointId& /* in_initiator */,
+        const std::optional<std::string>& /* in_serviceDescriptor */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::sendMessageToEndpoint(int32_t /* in_sessionId */,
+                                                const Message& /* in_msg */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::sendMessageDeliveryStatusToEndpoint(
+        int32_t /* in_sessionId */, const MessageDeliveryStatus& /* in_msgStatus */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::closeEndpointSession(int32_t /* in_sessionId */, Reason /* in_reason */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
+ScopedAStatus ContextHub::endpointSessionOpenComplete(int32_t /* in_sessionId */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+};
+
 }  // namespace aidl::android::hardware::contexthub
diff --git a/contexthub/aidl/default/contexthub-default.xml b/contexthub/aidl/default/contexthub-default.xml
index 2f8ddc8..359bb0a 100644
--- a/contexthub/aidl/default/contexthub-default.xml
+++ b/contexthub/aidl/default/contexthub-default.xml
@@ -1,7 +1,7 @@
 <manifest version="1.0" type="device">
     <hal format="aidl">
         <name>android.hardware.contexthub</name>
-        <version>3</version>
+        <version>4</version>
         <interface>
             <name>IContextHub</name>
             <instance>default</instance>
diff --git a/contexthub/aidl/default/include/contexthub-impl/ContextHub.h b/contexthub/aidl/default/include/contexthub-impl/ContextHub.h
index 72e8b3b..5680a77 100644
--- a/contexthub/aidl/default/include/contexthub-impl/ContextHub.h
+++ b/contexthub/aidl/default/include/contexthub-impl/ContextHub.h
@@ -53,6 +53,24 @@
             int32_t in_contextHubId,
             const MessageDeliveryStatus& in_messageDeliveryStatus) override;
 
+    ::ndk::ScopedAStatus getHubs(std::vector<HubInfo>* _aidl_return) override;
+    ::ndk::ScopedAStatus getEndpoints(std::vector<EndpointInfo>* _aidl_return) override;
+    ::ndk::ScopedAStatus registerEndpoint(const EndpointInfo& in_endpoint) override;
+    ::ndk::ScopedAStatus unregisterEndpoint(const EndpointInfo& in_endpoint) override;
+    ::ndk::ScopedAStatus registerEndpointCallback(
+            const std::shared_ptr<IEndpointCallback>& in_callback) override;
+    ::ndk::ScopedAStatus requestSessionIdRange(int32_t in_size,
+                                               std::vector<int32_t>* _aidl_return) override;
+    ::ndk::ScopedAStatus openEndpointSession(
+            int32_t in_sessionId, const EndpointId& in_destination, const EndpointId& in_initiator,
+            const std::optional<std::string>& in_serviceDescriptor) override;
+    ::ndk::ScopedAStatus sendMessageToEndpoint(int32_t in_sessionId,
+                                               const Message& in_msg) override;
+    ::ndk::ScopedAStatus sendMessageDeliveryStatusToEndpoint(
+            int32_t in_sessionId, const MessageDeliveryStatus& in_msgStatus) override;
+    ::ndk::ScopedAStatus closeEndpointSession(int32_t in_sessionId, Reason in_reason) override;
+    ::ndk::ScopedAStatus endpointSessionOpenComplete(int32_t in_sessionId) override;
+
   private:
     static constexpr uint32_t kMockHubId = 0;
     std::shared_ptr<IContextHubCallback> mCallback;