diff --git a/admin-client/build.gradle.kts b/admin-client/build.gradle.kts
index 03fc970fb..99613f8b8 100644
--- a/admin-client/build.gradle.kts
+++ b/admin-client/build.gradle.kts
@@ -43,6 +43,14 @@ tasks.withType<GenerateTask> {
 
   configOptions.put("openApiNullable", "false")
 
+  // This whole client is deprecated in favour of dev.restate.client.Client. We deprecate every
+  // generated type:
+  // * The custom generatedAnnotation.mustache template (see openapi-templates) adds @Deprecated to
+  //   all the api/model/invoker classes, right after the @Generated annotation.
+  // * additionalEnumTypeAnnotations covers the standalone enums, which don't carry @Generated.
+  templateDir.set("$projectDir/openapi-templates")
+  configOptions.put("additionalEnumTypeAnnotations", "@Deprecated")
+
   finalizedBy("spotlessJava")
 }
 
diff --git a/admin-client/openapi-templates/generatedAnnotation.mustache b/admin-client/openapi-templates/generatedAnnotation.mustache
new file mode 100644
index 000000000..9fdab2520
--- /dev/null
+++ b/admin-client/openapi-templates/generatedAnnotation.mustache
@@ -0,0 +1,2 @@
+@{{javaxPackage}}.annotation.Generated(value = "{{generatorClass}}"{{^hideGenerationTimestamp}}, date = "{{generatedDate}}"{{/hideGenerationTimestamp}}, comments = "Generator version: {{generatorVersion}}")
+@Deprecated
diff --git a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateAdminClient.java b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateAdminClient.java
index 6bf7b404e..1317685b3 100644
--- a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateAdminClient.java
+++ b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateAdminClient.java
@@ -16,7 +16,11 @@
 /**
  * Inject the Restate {@link dev.restate.admin.client.ApiClient}, useful to build admin clients,
  * such as {@link dev.restate.admin.api.DeploymentApi}.
+ *
+ * @deprecated The code-generated admin client (the {@code dev.restate.admin} package) is
+ *     deprecated. Use {@link RestateAdminURL} instead to inject the admin URL.
  */
+@Deprecated
 @Target(value = ElementType.PARAMETER)
 @Retention(RetentionPolicy.RUNTIME)
 public @interface RestateAdminClient {}
diff --git a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateAdminURL.java b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateAdminURL.java
new file mode 100644
index 000000000..95e9e2822
--- /dev/null
+++ b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateAdminURL.java
@@ -0,0 +1,24 @@
+// Copyright (c) 2023 - Restate Software, Inc., Restate GmbH
+//
+// This file is part of the Restate Java SDK,
+// which is released under the MIT license.
+//
+// You can find a copy of the license in file LICENSE in the root
+// directory of this repository or package, or at
+// https://github.com/restatedev/sdk-java/blob/main/LICENSE
+package dev.restate.sdk.testing;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.net.URI;
+import java.net.URL;
+
+/**
+ * Inject Restate's admin URL (either {@link String} or {@link URL} or {@link URI}) to interact with
+ * the <a href="https://docs.restate.dev/references/admin-api">admin API</a> of the deployed server.
+ */
+@Target(value = ElementType.PARAMETER)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface RestateAdminURL {}
diff --git a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateExtension.java b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateExtension.java
index ef1b333cf..928e886ad 100644
--- a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateExtension.java
+++ b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateExtension.java
@@ -33,6 +33,8 @@ public void beforeAll(ExtensionContext extensionContext) {
   }
 
   @Override
+  @SuppressWarnings(
+      "deprecation") // RestateAdminClient/ApiClient are deprecated but still supported
   public boolean supportsParameter(
       ParameterContext parameterContext, ExtensionContext extensionContext)
       throws ParameterResolutionException {
@@ -42,11 +44,14 @@ public boolean supportsParameter(
         || (parameterContext.isAnnotated(RestateClient.class)
             && Client.class.isAssignableFrom(parameterContext.getParameter().getType()))
         || (parameterContext.isAnnotated(RestateURL.class)
-            && (String.class.isAssignableFrom(parameterContext.getParameter().getType())
-                || URL.class.isAssignableFrom(parameterContext.getParameter().getType())));
+            && isStringOrUrlOrUri(parameterContext.getParameter().getType()))
+        || (parameterContext.isAnnotated(RestateAdminURL.class)
+            && isStringOrUrlOrUri(parameterContext.getParameter().getType()));
   }
 
   @Override
+  @SuppressWarnings(
+      "deprecation") // RestateAdminClient/ApiClient are deprecated but still supported
   public Object resolveParameter(
       ParameterContext parameterContext, ExtensionContext extensionContext)
       throws ParameterResolutionException {
@@ -57,22 +62,33 @@ public Object resolveParameter(
       URL url = runner.getIngressUrl();
       return Client.connect(url.toString());
     } else if (parameterContext.isAnnotated(RestateURL.class)) {
-      URL url = runner.getIngressUrl();
-      if (parameterContext.getParameter().getType().equals(String.class)) {
-        return url.toString();
-      }
-      if (parameterContext.getParameter().getType().equals(URI.class)) {
-        try {
-          return url.toURI();
-        } catch (URISyntaxException e) {
-          throw new RuntimeException(e);
-        }
-      }
-      return url;
+      return convertUrl(parameterContext.getParameter().getType(), runner.getIngressUrl());
+    } else if (parameterContext.isAnnotated(RestateAdminURL.class)) {
+      return convertUrl(parameterContext.getParameter().getType(), runner.getAdminUrl());
     }
     throw new ParameterResolutionException("The parameter is not supported");
   }
 
+  private static boolean isStringOrUrlOrUri(Class<?> type) {
+    return String.class.isAssignableFrom(type)
+        || URL.class.isAssignableFrom(type)
+        || URI.class.isAssignableFrom(type);
+  }
+
+  private static Object convertUrl(Class<?> type, URL url) {
+    if (type.equals(String.class)) {
+      return url.toString();
+    }
+    if (type.equals(URI.class)) {
+      try {
+        return url.toURI();
+      } catch (URISyntaxException e) {
+        throw new RuntimeException(e);
+      }
+    }
+    return url;
+  }
+
   private RestateRunner getOrCreateRunner(ExtensionContext extensionContext) {
     return extensionContext
         .getStore(NAMESPACE)
diff --git a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateRunner.java b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateRunner.java
index 2a27dfdb6..583c1bdc7 100644
--- a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateRunner.java
+++ b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateRunner.java
@@ -143,6 +143,8 @@ public RestateRunner build() {
   }
 
   /** Run restate, run the embedded service endpoint server, and register the services. */
+  @SuppressWarnings(
+      "deprecation") // Internally still uses the deprecated code-generated admin client
   public void start() {
     // Start listening the local server
     try {
@@ -234,6 +236,7 @@ public void close() {
 
   // -- Methods used by the JUnit5 extension
 
+  @SuppressWarnings("deprecation") // Returns the deprecated code-generated admin client
   ApiClient getAdminClient() {
     return new ApiClient()
         .setHost(runtimeContainer.getHost())
diff --git a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateTest.java b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateTest.java
index 667cf6335..1a8a8aee8 100644
--- a/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateTest.java
+++ b/sdk-testing/src/main/java/dev/restate/sdk/testing/RestateTest.java
@@ -45,8 +45,8 @@
  * test methods. Because of this behaviour, the extension sets the {@link TestInstance} as {@link
  * TestInstance.Lifecycle#PER_CLASS} automatically.
  *
- * <p>Use the annotations {@link RestateClient}, {@link RestateURL} and {@link RestateAdminClient}
- * to interact with the deployed environment:
+ * <p>Use the annotations {@link RestateClient}, {@link RestateURL} and {@link RestateAdminURL} to
+ * interact with the deployed environment:
  *
  * <pre>
  * {@code @Test}
diff --git a/sdk-testing/src/test/java/dev/restate/sdk/testing/CounterTest.java b/sdk-testing/src/test/java/dev/restate/sdk/testing/CounterTest.java
index 6b3510ae5..600f5dabd 100644
--- a/sdk-testing/src/test/java/dev/restate/sdk/testing/CounterTest.java
+++ b/sdk-testing/src/test/java/dev/restate/sdk/testing/CounterTest.java
@@ -11,6 +11,11 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 import dev.restate.client.Client;
+import java.net.URI;
+import java.net.URL;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.Timeout;
 
@@ -27,4 +32,15 @@ void testGreet(@RestateClient Client ingressClient) {
     long response = client.get();
     assertThat(response).isEqualTo(0L);
   }
+
+  @Test
+  @Timeout(value = 10)
+  void adminUrlIsInjected(@RestateAdminURL URL adminUrl) throws Exception {
+    HttpResponse<Void> response =
+        HttpClient.newHttpClient()
+            .send(
+                HttpRequest.newBuilder(URI.create(adminUrl.toString()).resolve("/health")).build(),
+                HttpResponse.BodyHandlers.discarding());
+    assertThat(response.statusCode()).isEqualTo(200);
+  }
 }