diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/ServiceModelGeneratorConstants.java b/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/ServiceModelGeneratorConstants.java
index 35fb17f71..e3b742330 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/ServiceModelGeneratorConstants.java
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/ServiceModelGeneratorConstants.java
@@ -35,6 +35,9 @@ public class ServiceModelGeneratorConstants {
     public static final String SINGLE_SELECT_VALUE = "SINGLE_SELECT";
     public static final String MULTIPLE_SELECT_VALUE = "MULTIPLE_SELECT";
 
+    public static final String HTTP_DEFAULT_LISTENER_REF = "default:httpListener";
+    public static final String HTTP_DEFAULT_MODULE = "http.default";
+
     public static final String KAFKA = "kafka";
     public static final String HTTP = "http";
     public static final String GRAPHQL = "graphql";
@@ -57,6 +60,7 @@ public class ServiceModelGeneratorConstants {
     public static final String VALUE_TYPE_EXPRESSION = "EXPRESSION";
     public static final String VALUE_TYPE_IDENTIFIER = "IDENTIFIER";
     public static final String VALUE_TYPE_TYPE = "TYPE";
+    public static final String HTTP_PARAM_TYPE_QUERY = "QUERY";
 
     public static final String TYPE_HTTP_SERVICE_CONFIG = "http:ServiceConfig";
 
diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/ServiceModelGeneratorService.java b/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/ServiceModelGeneratorService.java
index 776b25e90..5de627886 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/ServiceModelGeneratorService.java
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/ServiceModelGeneratorService.java
@@ -95,10 +95,12 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.stream.Collectors;
 
@@ -112,6 +114,7 @@
 import static io.ballerina.servicemodelgenerator.extension.Utils.getResourceFunctionModel;
 import static io.ballerina.servicemodelgenerator.extension.Utils.getServiceDeclarationNode;
 import static io.ballerina.servicemodelgenerator.extension.Utils.importExists;
+import static io.ballerina.servicemodelgenerator.extension.Utils.isHttpDefaultListenerAttached;
 import static io.ballerina.servicemodelgenerator.extension.Utils.isHttpServiceContractType;
 import static io.ballerina.servicemodelgenerator.extension.Utils.populateProperties;
 import static io.ballerina.servicemodelgenerator.extension.Utils.updateListenerModel;
@@ -172,7 +175,7 @@ public CompletableFuture<ListenerDiscoveryResponse> getListeners(ListenerDiscove
                 Module module = currentPackage.module(ModuleName.from(currentPackage.packageName()));
                 ModuleId moduleId = module.moduleId();
                 SemanticModel semanticModel = currentPackage.getCompilation().getSemanticModel(moduleId);
-                List<String> listeners = getCompatibleListeners(request.moduleName(), semanticModel);
+                Set<String> listeners = getCompatibleListeners(request.moduleName(), semanticModel);
                 return new ListenerDiscoveryResponse(listeners);
             } catch (Throwable e) {
                 return new ListenerDiscoveryResponse(e);
@@ -180,15 +183,24 @@ public CompletableFuture<ListenerDiscoveryResponse> getListeners(ListenerDiscove
         });
     }
 
-    private static List<String> getCompatibleListeners(String moduleName, SemanticModel semanticModel) {
-        return semanticModel.moduleSymbols().stream()
-                .filter(symbol -> symbol instanceof VariableSymbol)
-                .map(symbol -> (VariableSymbol) symbol)
-                .filter(variableSymbol -> variableSymbol.qualifiers().contains(Qualifier.LISTENER))
-                .filter(variableSymbol -> variableSymbol.typeDescriptor().getModule().isPresent() && variableSymbol
-                        .typeDescriptor().getModule().get().id().moduleName().equals(moduleName))
-                .map(variableSymbol -> variableSymbol.getName().orElse(""))
-                .toList();
+    private static Set<String> getCompatibleListeners(String moduleName, SemanticModel semanticModel) {
+        Set<String> listeners = new LinkedHashSet<>();
+        if (ServiceModelGeneratorConstants.HTTP.equals(moduleName)) {
+            listeners.add(ServiceModelGeneratorConstants.HTTP_DEFAULT_LISTENER_REF);
+        }
+
+        for (Symbol moduleSymbol : semanticModel.moduleSymbols()) {
+            if (!(moduleSymbol instanceof VariableSymbol variableSymbol)
+                    || !variableSymbol.qualifiers().contains(Qualifier.LISTENER)) {
+                continue;
+            }
+            Optional<ModuleSymbol> module = variableSymbol.typeDescriptor().getModule();
+            if (module.isEmpty() || !module.get().id().moduleName().equals(moduleName)) {
+                continue;
+            }
+            variableSymbol.getName().ifPresent(listeners::add);
+        }
+        return listeners;
     }
 
     /**
@@ -273,7 +285,7 @@ public CompletableFuture<ServiceModelResponse> getServiceModel(ServiceModelReque
                 }
                 SyntaxTree syntaxTree = document.get().syntaxTree();
                 ModulePartNode modulePartNode = syntaxTree.rootNode();
-                List<String> listenersList = getCompatibleListeners(request.moduleName(), semanticModel);
+                Set<String> listenersList = getCompatibleListeners(request.moduleName(), semanticModel);
                 if (Objects.nonNull(request.listenerName())) {
                     listener.addValue(request.listenerName());
                     removeAlreadyDefinedServiceTypes(serviceModel, request.listenerName(), modulePartNode);
@@ -284,7 +296,7 @@ public CompletableFuture<ServiceModelResponse> getServiceModel(ServiceModelReque
                     } else {
                         listener.setValueType(ServiceModelGeneratorConstants.MULTIPLE_SELECT_VALUE);
                     }
-                    listener.setItems(listenersList);
+                    listener.setItems(listenersList.stream().toList());
                 }
                 return new ServiceModelResponse(serviceModel);
             } catch (Throwable e) {
@@ -357,6 +369,14 @@ public CompletableFuture<CommonSourceResponse> addService(ServiceSourceRequest r
                     String importText = Utils.getImportStmt(service.getOrgName(), service.getModuleName());
                     edits.add(new TextEdit(Utils.toRange(lineRange.startLine()), importText));
                 }
+                if (ServiceModelGeneratorConstants.HTTP.equals(service.getModuleName())
+                        && isHttpDefaultListenerAttached(service.getListener()) &&
+                        !importExists(node, service.getOrgName(), ServiceModelGeneratorConstants.HTTP_DEFAULT_MODULE)) {
+                    String importText = Utils.getImportStmt(service.getOrgName(),
+                            ServiceModelGeneratorConstants.HTTP_DEFAULT_MODULE);
+                    edits.add(new TextEdit(Utils.toRange(lineRange.startLine()), importText));
+                }
+
                 edits.add(new TextEdit(Utils.toRange(lineRange.endLine()),
                         ServiceModelGeneratorConstants.LINE_SEPARATOR + serviceDeclaration));
                 return new CommonSourceResponse(Map.of(request.filePath(), edits));
@@ -522,15 +542,21 @@ public CompletableFuture<ServiceFromSourceResponse> getServiceFromSource(CommonM
             } else {
                 updateServiceModel(serviceModel, serviceNode, semanticModel);
             }
-            List<String> listenersList = getCompatibleListeners(serviceName.get(), semanticModel);
+            Set<String> listeners = getCompatibleListeners(serviceName.get(), semanticModel);
+            List<String> allValues = serviceModel.getListener().getValues();
+            if (allValues.isEmpty()) {
+                listeners.add(serviceModel.getListener().getValue());
+            } else {
+                listeners.addAll(allValues);
+            }
             Value listener = serviceModel.getListener();
-            if (!listenersList.isEmpty()) {
+            if (!listeners.isEmpty()) {
                 if (serviceName.get().equals(ServiceModelGeneratorConstants.KAFKA)) {
                     listener.setValueType(ServiceModelGeneratorConstants.SINGLE_SELECT_VALUE);
                 } else {
                     listener.setValueType(ServiceModelGeneratorConstants.MULTIPLE_SELECT_VALUE);
                 }
-                listener.setItems(listenersList);
+                listener.setItems(listeners.stream().toList());
             }
             return new ServiceFromSourceResponse(serviceModel);
         });
@@ -770,6 +796,14 @@ public CompletableFuture<CommonSourceResponse> updateService(ServiceModifierRequ
                         edits.add(listenerEdit);
                     }
                 }
+                if (ServiceModelGeneratorConstants.HTTP.equals(service.getModuleName()) &&
+                        isHttpDefaultListenerAttached(service.getListener()) &&
+                        !importExists(modulePartNode, service.getOrgName(),
+                                ServiceModelGeneratorConstants.HTTP_DEFAULT_MODULE)) {
+                    String importText = Utils.getImportStmt(service.getOrgName(),
+                            ServiceModelGeneratorConstants.HTTP_DEFAULT_MODULE);
+                    edits.add(new TextEdit(Utils.toRange(lineRange.startLine()), importText));
+                }
                 return new CommonSourceResponse(Map.of(request.filePath(), edits));
             } catch (Throwable e) {
                 return new CommonSourceResponse(e);
diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/Utils.java b/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/Utils.java
index 6920aa6fd..3e99b8d6d 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/Utils.java
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/Utils.java
@@ -462,7 +462,7 @@ public static Function getFunctionModel(MethodDeclarationNode functionDefinition
         SeparatedNodeList<ParameterNode> parameters = functionSignatureNode.parameters();
         List<Parameter> parameterModels = new ArrayList<>();
         parameters.forEach(parameterNode -> {
-            Optional<Parameter> parameterModel = getParameterModel(parameterNode);
+            Optional<Parameter> parameterModel = getParameterModel(parameterNode, isHttp);
             parameterModel.ifPresent(parameterModels::add);
         });
         functionModel.setParameters(parameterModels);
@@ -508,7 +508,7 @@ public static Function getFunctionModel(FunctionDefinitionNode functionDefinitio
         SeparatedNodeList<ParameterNode> parameters = functionSignatureNode.parameters();
         List<Parameter> parameterModels = new ArrayList<>();
         parameters.forEach(parameterNode -> {
-            Optional<Parameter> parameterModel = getParameterModel(parameterNode);
+            Optional<Parameter> parameterModel = getParameterModel(parameterNode, isHttp);
             parameterModel.ifPresent(parameterModels::add);
         });
         functionModel.setParameters(parameterModels);
@@ -700,18 +700,18 @@ public static Optional<String> getHttpParameterType(NodeList<AnnotationNode> ann
         return Optional.empty();
     }
 
-    public static Optional<Parameter> getParameterModel(ParameterNode parameterNode) {
+    public static Optional<Parameter> getParameterModel(ParameterNode parameterNode, boolean isHttp) {
         if (parameterNode instanceof RequiredParameterNode parameter) {
             String paramName = parameter.paramName().get().toString().trim();
             Parameter parameterModel = createParameter(paramName, ServiceModelGeneratorConstants.KIND_REQUIRED,
                     ServiceModelGeneratorConstants.VALUE_TYPE_IDENTIFIER, parameter.typeName().toString().trim(),
-                    parameter.annotations());
+                    parameter.annotations(), isHttp);
             return Optional.of(parameterModel);
         } else if (parameterNode instanceof DefaultableParameterNode parameter) {
             String paramName = parameter.paramName().get().toString().trim();
             Parameter parameterModel = createParameter(paramName, ServiceModelGeneratorConstants.KIND_DEFAULTABLE,
                     ServiceModelGeneratorConstants.VALUE_TYPE_EXPRESSION, parameter.typeName().toString().trim(),
-                    parameter.annotations());
+                    parameter.annotations(), isHttp);
             Value defaultValue = parameterModel.getDefaultValue();
             defaultValue.setValue(parameter.expression().toString().trim());
             defaultValue.setValueType(ServiceModelGeneratorConstants.VALUE_TYPE_EXPRESSION);
@@ -722,11 +722,18 @@ public static Optional<Parameter> getParameterModel(ParameterNode parameterNode)
     }
 
     private static Parameter createParameter(String paramName, String paramKind, String valueType, String typeName,
-                                             NodeList<AnnotationNode> annotationNodes) {
+                                             NodeList<AnnotationNode> annotationNodes, boolean isHttp) {
         Parameter parameterModel = Parameter.getNewParameter();
         parameterModel.setMetadata(new MetaData(paramName, paramName));
         parameterModel.setKind(paramKind);
-        getHttpParameterType(annotationNodes).ifPresent(parameterModel::setHttpParamType);
+        if (isHttp) {
+            Optional<String> httpParameterType = getHttpParameterType(annotationNodes);
+            if (httpParameterType.isPresent()) {
+                parameterModel.setHttpParamType(httpParameterType.get());
+            } else {
+                parameterModel.setHttpParamType(ServiceModelGeneratorConstants.HTTP_PARAM_TYPE_QUERY);
+            }
+        }
         Value type = parameterModel.getType();
         type.setValue(typeName);
         type.setValueType(ServiceModelGeneratorConstants.VALUE_TYPE_TYPE);
@@ -1233,4 +1240,17 @@ public static String getExprUri(String sourcePath) {
         String exprUriString = "expr" + Paths.get(sourcePath).toUri().toString().substring(4);
         return URI.create(exprUriString).toString();
     }
+
+    /**
+     * Check if the `default:httpListener` is attached to the service.
+     *
+     * @param value the Listener value
+     * @return true if the `default:httpListener` is attached, false otherwise
+     */
+    public static boolean isHttpDefaultListenerAttached(Value value) {
+        if (value.getValues().isEmpty()) {
+            return ServiceModelGeneratorConstants.HTTP_DEFAULT_LISTENER_REF.equals(value.getValue().trim());
+        }
+        return value.getValues().contains(ServiceModelGeneratorConstants.HTTP_DEFAULT_LISTENER_REF);
+    }
 }
diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/response/ListenerDiscoveryResponse.java b/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/response/ListenerDiscoveryResponse.java
index a99dee65e..888910da9 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/response/ListenerDiscoveryResponse.java
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/main/java/io/ballerina/servicemodelgenerator/extension/response/ListenerDiscoveryResponse.java
@@ -18,22 +18,22 @@
 
 package io.ballerina.servicemodelgenerator.extension.response;
 
-import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
 
-public record ListenerDiscoveryResponse(boolean hasListeners, List<String> listeners, String errorMsg,
+public record ListenerDiscoveryResponse(boolean hasListeners, Set<String> listeners, String errorMsg,
                                         String stacktrace) {
 
     public ListenerDiscoveryResponse() {
-        this(false, new ArrayList<>(), null, null);
+        this(false, new HashSet<>(), null, null);
     }
 
-    public ListenerDiscoveryResponse(List<String> listeners) {
+    public ListenerDiscoveryResponse(Set<String> listeners) {
         this(!listeners.isEmpty(), listeners, null, null);
     }
 
     public ListenerDiscoveryResponse(Throwable e) {
-        this(false, new ArrayList<>(), e.toString(), Arrays.toString(e.getStackTrace()));
+        this(false, new HashSet<>(), e.toString(), Arrays.toString(e.getStackTrace()));
     }
 }
diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/test/java/io/ballerina/servicemodelgenerator/extension/ServiceModelAPITests.java b/service-model-generator/modules/service-model-generator-ls-extension/src/test/java/io/ballerina/servicemodelgenerator/extension/ServiceModelAPITests.java
index 1da82166e..760cc3eca 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/test/java/io/ballerina/servicemodelgenerator/extension/ServiceModelAPITests.java
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/test/java/io/ballerina/servicemodelgenerator/extension/ServiceModelAPITests.java
@@ -80,8 +80,8 @@ public void testListenerDiscoveryWithEmptyFile() throws ExecutionException, Inte
                 "ballerina", "http");
         CompletableFuture<?> result = serviceEndpoint.request("serviceDesign/getListeners", request);
         ListenerDiscoveryResponse response = (ListenerDiscoveryResponse) result.get();
-        Assert.assertFalse(response.hasListeners());
-        Assert.assertEquals(response.listeners().size(), 0);
+        Assert.assertTrue(response.hasListeners());
+        Assert.assertEquals(response.listeners().size(), 1);
     }
 
     @Test(enabled = false)
@@ -204,7 +204,7 @@ public void testAddHttpService() throws ExecutionException, InterruptedException
         ServiceModelResponse modelResponse = (ServiceModelResponse) modelResult.get();
         Service service = modelResponse.service();
         Assert.assertTrue(Objects.nonNull(service));
-        service.getListener().setValues(List.of("httpTestListener", "httpsTestListener"));
+        service.getListener().setValues(List.of("default:httpListener", "httpsTestListener"));
         Value designApproach = service.getDesignApproach();
         Value selectedApproach = designApproach.getChoices().getFirst();
         Value basePath = selectedApproach.getProperty("basePath");
@@ -523,7 +523,7 @@ public void testUpdateHttpService() throws ExecutionException, InterruptedExcept
         ServiceFromSourceResponse sourceResponse = (ServiceFromSourceResponse) sourceResult.get();
         Service service = sourceResponse.service();
         Assert.assertTrue(Objects.nonNull(service));
-        service.getListener().setValue("newHttpListener");
+        service.getListener().setValues(List.of("newHttpListener", "default:httpListener"));
         service.getBasePath().setValue("/api/v1/test/new");
 
         ServiceModifierRequest updateRequest = new ServiceModifierRequest(filePath.toAbsolutePath().toString(),
diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_anonymous_listener.json b/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_anonymous_listener.json
index df8df5636..56cd5f34e 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_anonymous_listener.json
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_anonymous_listener.json
@@ -39,6 +39,10 @@
         "placeholder": "",
         "optional": false,
         "advanced": false,
+        "items": [
+          "default:httpListener",
+          "new http:Listener(port = 8080)"
+        ],
         "codedata": {
           "inListenerInit": false,
           "isBasePath": false,
@@ -371,7 +375,8 @@
             "enabled": true,
             "editable": false,
             "optional": false,
-            "advanced": false
+            "advanced": false,
+            "httpParamType": "QUERY"
           }
         ],
         "schema": {
diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_global_listener.json b/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_global_listener.json
index 84225cba2..f5c8ade9c 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_global_listener.json
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_global_listener.json
@@ -45,7 +45,10 @@
         "optional": false,
         "advanced": false,
         "items": [
+          "default:globalListener",
+          "default:httpListener",
           "httpListener",
+          "new http:Listener(port = 8080)",
           "githubListener"
         ],
         "codedata": {
diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_multiple_listeners.json b/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_multiple_listeners.json
index e0f02abbc..1d62a2e57 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_multiple_listeners.json
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_multiple_listeners.json
@@ -44,7 +44,9 @@
         "optional": false,
         "advanced": false,
         "items": [
+          "default:httpListener",
           "httpListener",
+          "new http:Listener(port = 8080)",
           "githubListener"
         ],
         "codedata": {
diff --git a/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_single_listener.json b/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_single_listener.json
index 9935650f9..ba06fc45d 100644
--- a/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_single_listener.json
+++ b/service-model-generator/modules/service-model-generator-ls-extension/src/test/resources/get_sm_from_source/config/http_service_with_single_listener.json
@@ -40,6 +40,7 @@
         "optional": false,
         "advanced": false,
         "items": [
+          "default:httpListener",
           "httpListener",
           "githubListener"
         ],
@@ -375,7 +376,8 @@
             "enabled": true,
             "editable": false,
             "optional": false,
-            "advanced": false
+            "advanced": false,
+            "httpParamType": "QUERY"
           }
         ],
         "schema": {