Class Event

src/google/adk/events/event.py:91–303

Represents an event in a conversation between agents and users. It is used to store the content of the conversation, as well as the actions taken by the agents like function calls, etc.

class Event(LlmResponse):
  """Represents an event in a conversation between agents and users.

  It is used to store the content of the conversation, as well as the actions
  taken by the agents like function calls, etc.
  """

  model_config = ConfigDict(
      extra='ignore',
      ser_json_bytes='base64',
      val_json_bytes='base64',
      alias_generator=alias_generators.to_camel,
      populate_by_name=True,
  )
  """The pydantic model config."""

  invocation_id: str = ''
  """The invocation ID of the event. Should be non-empty before appending to a session."""
  author: str = ''
  """'user' or the name of the agent, indicating who appended the event to the
  session."""
  actions: EventActions = Field(default_factory=EventActions)
  """The actions taken by the agent."""

  output: Any | None = None
  """Generic data output from a workflow node."""

  node_info: NodeInfo = Field(default_factory=NodeInfo)
  """Workflow node metadata (path, run_id, etc.)."""

  long_running_tool_ids: set[str] | None = None
  """Set of ids of the long running function calls.
  Agent client will know from this field about which function call is long running.
  only valid for function call event
  """
  branch: str | None = None
  """The branch of the event.

  The format is like agent_1.agent_2.agent_3, where agent_1 is the parent of
  agent_2, and agent_2 is the parent of agent_3.

  Branch is used when multiple sub-agent shouldn't see their peer agents'
  conversation history.
  """
  isolation_scope: str | None = None
  """Scope tag indicating which logical context this event belongs to.

  When set, the LLM content-builder restricts session events visible to
  an agent to those whose ``isolation_scope`` matches the agent's own
  scope.  One usage today is the Task API: a delegated task agent is
  scoped under the originating function-call id (``<fc_id>``) so it
  sees only its own task&#x27;s events, isolated from the chat
  coordinator&#x27;s broader conversation.

  ⚠️ DO NOT USE THIS FIELD DIRECTLY.  It is an internal mechanism that
  may change without notice.  External code should not read, write, or
  rely on its semantics.
  """