feat: Add invocationContext() to ReadOnlyContext

When using callbacks, developers should be able to access the InvocationContext. From there, it allows them to access the Session, and from the Session also to access Events, etc.

This would align with Python which allows to access the invocation context.

PiperOrigin-RevId: 781590060

Author: google-genai-bot

core/src/main/java/com/google/adk/agents/CallbackContext.java

@@ -18,6 +18,7 @@
 
 import com.google.adk.events.EventActions;
 import com.google.adk.sessions.State;
+import com.google.genai.types.Content;
 import com.google.genai.types.Part;
 import io.reactivex.rxjava3.core.Maybe;
 import java.util.Optional;
@@ -46,6 +47,11 @@ public State state() {
     return state;
   }
 
+  /** Returns the user content that initiated this invocation. */
+  public Optional<Content> userContent() {
+    return invocationContext.userContent();
+  }
+
   /** Returns the EventActions associated with this context. */
   public EventActions eventActions() {
     return eventActions;

core/src/main/java/com/google/adk/agents/LlmAgent.java

@@ -16,7 +16,6 @@
 
 package com.google.adk.agents;
 
-import static com.google.common.collect.ImmutableList.toImmutableList;
 import static java.util.stream.Collectors.joining;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
@@ -48,7 +47,6 @@
 import com.google.adk.models.BaseLlm;
 import com.google.adk.models.Model;
 import com.google.adk.tools.BaseTool;
-import com.google.adk.tools.BaseToolset;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
@@ -58,7 +56,6 @@
 import io.reactivex.rxjava3.core.Flowable;
 import io.reactivex.rxjava3.core.Maybe;
 import io.reactivex.rxjava3.core.Single;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -84,7 +81,7 @@ public enum IncludeContents {
   private final Optional<Model> model;
   private final Instruction instruction;
   private final Instruction globalInstruction;
-  private final List<Object> toolsUnion;
+  private final List<BaseTool> tools;
   private final Optional<GenerateContentConfig> generateContentConfig;
   private final Optional<BaseExampleProvider> exampleProvider;
   private final IncludeContents includeContents;
@@ -133,7 +130,7 @@ protected LlmAgent(Builder builder) {
     this.outputSchema = Optional.ofNullable(builder.outputSchema);
     this.executor = Optional.ofNullable(builder.executor);
     this.outputKey = Optional.ofNullable(builder.outputKey);
-    this.toolsUnion = builder.toolsUnion != null ? builder.toolsUnion : ImmutableList.of();
+    this.tools = builder.tools != null ? builder.tools : ImmutableList.of();
 
     this.llmFlow = determineLlmFlow();
 
@@ -156,7 +153,7 @@ public static class Builder {
     private Instruction instruction;
     private Instruction globalInstruction;
     private ImmutableList<BaseAgent> subAgents;
-    private ImmutableList<Object> toolsUnion;
+    private ImmutableList<BaseTool> tools;
     private GenerateContentConfig generateContentConfig;
     private BaseExampleProvider exampleProvider;
     private IncludeContents includeContents;
@@ -237,14 +234,14 @@ public Builder subAgents(BaseAgent... subAgents) {
     }
 
     @CanIgnoreReturnValue
-    public Builder tools(List<?> tools) {
-      this.toolsUnion = ImmutableList.copyOf(tools);
+    public Builder tools(List<? extends BaseTool> tools) {
+      this.tools = ImmutableList.copyOf(tools);
       return this;
     }
 
     @CanIgnoreReturnValue
-    public Builder tools(Object... tools) {
-      this.toolsUnion = ImmutableList.copyOf(tools);
+    public Builder tools(BaseTool... tools) {
+      this.tools = ImmutableList.copyOf(tools);
       return this;
     }
 
@@ -583,7 +580,7 @@ protected void validate() {
                   + ": if outputSchema is set, subAgents must be empty to disable agent"
                   + " transfer.");
         }
-        if (this.toolsUnion != null && !this.toolsUnion.isEmpty()) {
+        if (this.tools != null && !this.tools.isEmpty()) {
           throw new IllegalArgumentException(
               "Invalid config for agent "
                   + this.name
@@ -690,42 +687,6 @@ public Single<String> canonicalGlobalInstruction(ReadonlyContext context) {
     throw new IllegalStateException("Unknown Instruction subtype: " + instruction.getClass());
   }
 
-  /**
-   * Constructs the list of tools for this agent based on the {@link #tools} field.
-   *
-   * <p>This method is only for use by Agent Development Kit.
-   *
-   * @param context The context to retrieve the session state.
-   * @return The resolved list of tools as a {@link Single} wrapped list of {@link BaseTool}.
-   */
-  public Single<List<BaseTool>> canonicalTools(Optional<ReadonlyContext> context) {
-    List<Single<List<BaseTool>>> toolSingles = new ArrayList<>();
-    for (Object toolOrToolset : toolsUnion) {
-      if (toolOrToolset instanceof BaseTool baseTool) {
-        toolSingles.add(Single.just(ImmutableList.of(baseTool)));
-      } else if (toolOrToolset instanceof BaseToolset baseToolset) {
-        toolSingles.add(baseToolset.getTools(context.orElse(null)));
-      } else {
-        throw new IllegalArgumentException(
-            "Object in tools list is not of a supported type: "
-                + toolOrToolset.getClass().getName());
-      }
-    }
-    return Single.concat(toolSingles)
-        .toList()
-        .map(listOfLists -> listOfLists.stream().flatMap(List::stream).collect(toImmutableList()));
-  }
-
-  /** Overload of canonicalTools that defaults to an empty context. */
-  public Single<List<BaseTool>> canonicalTools() {
-    return canonicalTools(Optional.empty());
-  }
-
-  /** Convenience overload of canonicalTools that accepts a non-optional ReadonlyContext. */
-  public Single<List<BaseTool>> canonicalTools(ReadonlyContext context) {
-    return canonicalTools(Optional.ofNullable(context));
-  }
-
   public Instruction instruction() {
     return instruction;
   }
@@ -758,8 +719,8 @@ public IncludeContents includeContents() {
     return includeContents;
   }
 
-  public List<Object> tools() {
-    return toolsUnion;
+  public List<BaseTool> tools() {
+    return tools;
   }
 
   public boolean disallowTransferToParent() {

core/src/main/java/com/google/adk/agents/ReadonlyContext.java

@@ -17,7 +17,6 @@
 package com.google.adk.agents;
 
 import com.google.common.collect.ImmutableMap;
-import com.google.genai.types.Content;
 import java.util.Map;
 import java.util.Optional;
 
@@ -30,11 +29,6 @@ public ReadonlyContext(InvocationContext invocationContext) {
     this.invocationContext = invocationContext;
   }
 
-  /** Returns the user content that initiated this invocation. */
-  public Optional<Content> userContent() {
-    return invocationContext.userContent();
-  }
-
   /** Returns the ID of the current invocation. */
   public String invocationId() {
     return invocationContext.invocationId();
@@ -50,6 +44,11 @@ public String agentName() {
     return invocationContext.agent().name();
   }
 
+  /** Returns the invocation context. */
+  public InvocationContext invocationContext() {
+    return invocationContext;
+  }
+
   /**
    * Returns a read-only view of the state of the current session.
    *

core/src/main/java/com/google/adk/flows/llmflows/BaseLlmFlow.java

@@ -24,7 +24,6 @@
 import com.google.adk.agents.InvocationContext;
 import com.google.adk.agents.LiveRequest;
 import com.google.adk.agents.LlmAgent;
-import com.google.adk.agents.ReadonlyContext;
 import com.google.adk.agents.RunConfig.StreamingMode;
 import com.google.adk.events.Event;
 import com.google.adk.exceptions.LlmCallsLimitExceededException;
@@ -113,22 +112,20 @@ protected Single<RequestProcessingResult> preprocess(
         processedRequest -> {
           LlmRequest.Builder updatedRequestBuilder = processedRequest.toBuilder();
 
-          return agent
-              .canonicalTools(new ReadonlyContext(context))
-              .flatMapCompletable(
-                  tools ->
-                      Flowable.fromIterable(tools)
-                          .concatMapCompletable(
-                              tool ->
-                                  tool.processLlmRequest(
-                                      updatedRequestBuilder, ToolContext.builder(context).build())))
-              .andThen(
-                  Single.fromCallable(
-                      () -> {
-                        Iterable<Event> combinedEvents = Iterables.concat(eventIterables);
-                        return RequestProcessingResult.create(
-                            updatedRequestBuilder.build(), combinedEvents);
-                      }));
+          Completable toolProcessingCompletable =
+              Flowable.fromIterable(agent.tools())
+                  .concatMapCompletable(
+                      tool ->
+                          tool.processLlmRequest(
+                              updatedRequestBuilder, ToolContext.builder(context).build()));
+
+          return toolProcessingCompletable.andThen(
+              Single.fromCallable(
+                  () -> {
+                    Iterable<Event> combinedEvents = Iterables.concat(eventIterables);
+                    return RequestProcessingResult.create(
+                        updatedRequestBuilder.build(), combinedEvents);
+                  }));
         });
   }