diff --git a/a2a/src/main/java/com/google/adk/a2a/AgentExecutor.java b/a2a/src/main/java/com/google/adk/a2a/AgentExecutor.java
index 6df01694a..b98fba314 100644
--- a/a2a/src/main/java/com/google/adk/a2a/AgentExecutor.java
+++ b/a2a/src/main/java/com/google/adk/a2a/AgentExecutor.java
@@ -2,8 +2,13 @@
 
 import com.google.adk.a2a.converters.EventConverter;
 import com.google.adk.a2a.converters.PartConverter;
+import com.google.adk.agents.BaseAgent;
 import com.google.adk.agents.RunConfig;
+import com.google.adk.apps.App;
+import com.google.adk.artifacts.BaseArtifactService;
 import com.google.adk.events.Event;
+import com.google.adk.memory.BaseMemoryService;
+import com.google.adk.plugins.Plugin;
 import com.google.adk.runner.Runner;
 import com.google.adk.sessions.BaseSessionService;
 import com.google.adk.sessions.Session;
@@ -21,6 +26,7 @@
 import io.reactivex.rxjava3.core.Maybe;
 import io.reactivex.rxjava3.disposables.CompositeDisposable;
 import io.reactivex.rxjava3.disposables.Disposable;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.UUID;
@@ -41,29 +47,96 @@ public class AgentExecutor implements io.a2a.server.agentexecution.AgentExecutor
   private static final RunConfig DEFAULT_RUN_CONFIG =
       RunConfig.builder().setStreamingMode(RunConfig.StreamingMode.NONE).setMaxLlmCalls(20).build();
 
-  private final Runner runner;
   private final Map<String, Disposable> activeTasks = new ConcurrentHashMap<>();
+  private final Runner.Builder runnerBuilder;
+  private final RunConfig runConfig;
 
-  private AgentExecutor(Runner runner) {
-    this.runner = runner;
+  private AgentExecutor(
+      App app,
+      BaseAgent agent,
+      String appName,
+      BaseArtifactService artifactService,
+      BaseSessionService sessionService,
+      BaseMemoryService memoryService,
+      List<? extends Plugin> plugins,
+      RunConfig runConfig) {
+    this.runnerBuilder =
+        Runner.builder()
+            .app(app)
+            .agent(agent)
+            .appName(appName)
+            .artifactService(artifactService)
+            .sessionService(sessionService)
+            .memoryService(memoryService)
+            .plugins(plugins);
+    // Check that the runner is configured correctly and can be built.
+    var unused = runnerBuilder.build();
+    this.runConfig = runConfig == null ? DEFAULT_RUN_CONFIG : runConfig;
   }
 
   /** Builder for {@link AgentExecutor}. */
   public static class Builder {
-    private Runner runner;
+    private App app;
+    private BaseAgent agent;
+    private String appName;
+    private BaseArtifactService artifactService;
+    private BaseSessionService sessionService;
+    private BaseMemoryService memoryService;
+    private List<? extends Plugin> plugins;
+    private RunConfig runConfig;
 
     @CanIgnoreReturnValue
-    public Builder runner(Runner runner) {
-      this.runner = runner;
+    public Builder app(App app) {
+      this.app = app;
+      return this;
+    }
+
+    @CanIgnoreReturnValue
+    public Builder agent(BaseAgent agent) {
+      this.agent = agent;
+      return this;
+    }
+
+    @CanIgnoreReturnValue
+    public Builder appName(String appName) {
+      this.appName = appName;
+      return this;
+    }
+
+    @CanIgnoreReturnValue
+    public Builder artifactService(BaseArtifactService artifactService) {
+      this.artifactService = artifactService;
+      return this;
+    }
+
+    @CanIgnoreReturnValue
+    public Builder sessionService(BaseSessionService sessionService) {
+      this.sessionService = sessionService;
+      return this;
+    }
+
+    @CanIgnoreReturnValue
+    public Builder memoryService(BaseMemoryService memoryService) {
+      this.memoryService = memoryService;
+      return this;
+    }
+
+    @CanIgnoreReturnValue
+    public Builder plugins(List<? extends Plugin> plugins) {
+      this.plugins = plugins;
+      return this;
+    }
+
+    @CanIgnoreReturnValue
+    public Builder runConfig(RunConfig runConfig) {
+      this.runConfig = runConfig;
       return this;
     }
 
     @CanIgnoreReturnValue
     public AgentExecutor build() {
-      if (runner == null) {
-        throw new IllegalStateException("Runner must be provided.");
-      }
-      return new AgentExecutor(runner);
+      return new AgentExecutor(
+          app, agent, appName, artifactService, sessionService, memoryService, plugins, runConfig);
     }
   }
 
@@ -96,13 +169,14 @@ public void execute(RequestContext ctx, EventQueue eventQueue) {
 
     EventProcessor p = new EventProcessor();
     Content content = PartConverter.messageToContent(message);
+    Runner runner = runnerBuilder.build();
 
     taskDisposables.add(
-        prepareSession(ctx, runner.sessionService())
+        prepareSession(ctx, runner.appName(), runner.sessionService())
             .flatMapPublisher(
                 session -> {
                   updater.startWork();
-                  return runner.runAsync(getUserId(ctx), session.id(), content, DEFAULT_RUN_CONFIG);
+                  return runner.runAsync(getUserId(ctx), session.id(), content, runConfig);
                 })
             .subscribe(
                 event -> {
@@ -130,13 +204,14 @@ private String getUserId(RequestContext ctx) {
     return USER_ID_PREFIX + ctx.getContextId();
   }
 
-  private Maybe<Session> prepareSession(RequestContext ctx, BaseSessionService service) {
+  private Maybe<Session> prepareSession(
+      RequestContext ctx, String appName, BaseSessionService service) {
     return service
-        .getSession(runner.appName(), getUserId(ctx), ctx.getContextId(), Optional.empty())
+        .getSession(appName, getUserId(ctx), ctx.getContextId(), Optional.empty())
         .switchIfEmpty(
             Maybe.defer(
                 () -> {
-                  return service.createSession(runner.appName(), getUserId(ctx)).toMaybe();
+                  return service.createSession(appName, getUserId(ctx)).toMaybe();
                 }));
   }