diff --git a/core/src/main/java/com/google/adk/flows/llmflows/Basic.java b/core/src/main/java/com/google/adk/flows/llmflows/Basic.java
index 423891001..e3a214f34 100644
--- a/core/src/main/java/com/google/adk/flows/llmflows/Basic.java
+++ b/core/src/main/java/com/google/adk/flows/llmflows/Basic.java
@@ -38,9 +38,19 @@ public Single<RequestProcessor.RequestProcessingResult> processRequest(
     }
     LlmAgent agent = (LlmAgent) context.agent();
     String modelName =
-        agent.resolvedModel().model().isPresent()
-            ? agent.resolvedModel().model().get().model()
-            : agent.resolvedModel().modelName().get();
+        agent
+            .resolvedModel()
+            .model()
+            .map(model -> model.model())
+            .orElseGet(
+                () ->
+                    agent
+                        .resolvedModel()
+                        .modelName()
+                        .orElseThrow(
+                            () ->
+                                new IllegalStateException(
+                                    "Both model and modelName are not present in resolvedModel")));
 
     LiveConnectConfig.Builder liveConnectConfigBuilder =
         LiveConnectConfig.builder().responseModalities(context.runConfig().responseModalities());
diff --git a/core/src/main/java/com/google/adk/flows/llmflows/OutputSchema.java b/core/src/main/java/com/google/adk/flows/llmflows/OutputSchema.java
index d8d245bf6..ac798c077 100644
--- a/core/src/main/java/com/google/adk/flows/llmflows/OutputSchema.java
+++ b/core/src/main/java/com/google/adk/flows/llmflows/OutputSchema.java
@@ -59,7 +59,14 @@ public Single<RequestProcessingResult> processRequest(
     }
 
     // Add the set_model_response tool to handle structured output
-    SetModelResponseTool setResponseTool = new SetModelResponseTool(agent.outputSchema().get());
+    SetModelResponseTool setResponseTool =
+        new SetModelResponseTool(
+            agent
+                .outputSchema()
+                .orElseThrow(
+                    () ->
+                        new IllegalStateException(
+                            "outputSchema should be present when toolsUnion is not empty")));
     LlmRequest.Builder builder = request.toBuilder();
 
     return setResponseTool
diff --git a/core/src/main/java/com/google/adk/flows/llmflows/RequestConfirmationLlmRequestProcessor.java b/core/src/main/java/com/google/adk/flows/llmflows/RequestConfirmationLlmRequestProcessor.java
index b769c33bb..1024466d4 100644
--- a/core/src/main/java/com/google/adk/flows/llmflows/RequestConfirmationLlmRequestProcessor.java
+++ b/core/src/main/java/com/google/adk/flows/llmflows/RequestConfirmationLlmRequestProcessor.java
@@ -75,9 +75,12 @@ public Single<RequestProcessor.RequestProcessingResult> processRequest(
       return Single.just(RequestProcessingResult.create(llmRequest, ImmutableList.of()));
     }
 
-    int finalConfirmationEventIndex = confirmationResult.get().eventIndex();
+    ConfirmationResult result =
+        confirmationResult.orElseThrow(
+            () -> new IllegalStateException("confirmationResult should be present when not empty"));
+    int finalConfirmationEventIndex = result.eventIndex();
     ImmutableMap<String, ToolConfirmation> requestConfirmationFunctionResponses =
-        confirmationResult.get().responses();
+        result.responses();
     String agentName = invocationContext.agent().name();
     ImmutableMap<String, AuthoredFunctionCall> functionCallsById =
         functionCallsById(events, agentName);
@@ -129,10 +132,22 @@ public Single<RequestProcessor.RequestProcessingResult> processRequest(
                                   ofc, functionCallsById, confirmationRequestedIds, agentName))
                       .ifPresent(
                           ofc -> {
+                            String functionId =
+                                ofc.id()
+                                    .orElseThrow(
+                                        () ->
+                                            new IllegalStateException(
+                                                "Function call should have an ID"));
+                            String confirmationId =
+                                fc.id()
+                                    .orElseThrow(
+                                        () ->
+                                            new IllegalStateException(
+                                                "Function call should have an ID"));
                             toolsToResumeWithConfirmation.put(
-                                ofc.id().get(),
-                                requestConfirmationFunctionResponses.get(fc.id().get()));
-                            toolsToResumeWithArgs.put(ofc.id().get(), ofc);
+                                functionId,
+                                requestConfirmationFunctionResponses.get(confirmationId));
+                            toolsToResumeWithArgs.put(functionId, ofc);
                           }));
 
       // If all confirmed tools in this event have already been processed, continue