Class Start

java.lang.Object
com.google.adk.workflow.Start
All Implemented Interfaces:
Node
@Experimental public final class Start extends Object implements Node
The node that marks where a workflow graph starts. It never runs: the workflow passes its own input to the nodes that Start has edges to.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final Start
    INSTANCE
    The start node that every graph uses.

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    name()
    Returns the name that identifies the node within its graph.
    io.reactivex.rxjava3.core.Flowable<?>
    runNode(Context context, @Nullable Object nodeInput)
    Runs the node on nodeInput, the output it receives from its predecessors.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface Node

    config, description, inputSchema, outputSchema, requiresAllPredecessors, rerunOnResume, stateSchema, waitForOutput
    Modifier and Type
    Method
    Description
    default NodeConfig
    config()
    Returns the node's retry policy and execution timeout.
    default String
    description()
    Returns what the node does, for humans and for a model that may call it.
    default Optional<com.google.genai.types.Schema>
    inputSchema()
    Returns the schema the node's input must match.
    default Optional<com.google.genai.types.Schema>
    outputSchema()
    Returns the schema that the node's output value must match.
    default boolean
    requiresAllPredecessors()
    Returns true if the node runs only once every predecessor has completed, receiving all their outputs keyed by node name, as a fan-in node does.
    default boolean
    rerunOnResume()
    Returns true if a resumed node runs again from scratch, rather than completing with the resuming answer as its output.
    default Optional<com.google.genai.types.Schema>
    stateSchema()
    Returns the schema declaring the state keys the node uses.
    default boolean
    waitForOutput()
    Returns true if the node stays re-triggerable until it produces an output or a route, instead of completing when its run completes.

  • Field Details

    • INSTANCE

      public static final Start INSTANCE
      The start node that every graph uses.

  • Method Details

    • name

      public String name()
      Description copied from interface: Node
      Returns the name that identifies the node within its graph.
      Specified by:
      name in interface Node

    • runNode

      public io.reactivex.rxjava3.core.Flowable<?> runNode(Context context, @Nullable Object nodeInput)
      Description copied from interface: Node
      Runs the node on nodeInput, the output it receives from its predecessors.

      An emitted Event passes through, and any other emitted value becomes the node's output (at most one per run); emit nothing for no output, since RxJava forbids null. The wildcard lets an implementation return a Flowable of its own type.

      Specified by:
      runNode in interface Node