Class InvocationContext

src/google/adk/agents/invocation_context.py:103–486

An invocation context represents the data of a single invocation of an agent. An invocation: 1. Starts with a user message and ends with a final response. 2. Can contain one or multiple agent calls. 3. Is handled by runner.run_async(). An invocation runs an agent until it does not

class InvocationContext(BaseModel):
  """An invocation context represents the data of a single invocation of an agent.

  An invocation:
    1. Starts with a user message and ends with a final response.
    2. Can contain one or multiple agent calls.
    3. Is handled by runner.run_async().

  An invocation runs an agent until it does not request to transfer to another
  agent.

  An agent call:
    1. Is handled by agent.run().
    2. Ends when agent.run() ends.

  An LLM agent call is an agent with a BaseLLMFlow.
  An LLM agent call can contain one or multiple steps.

  An LLM agent runs steps in a loop until:
    1. A final response is generated.
    2. The agent transfers to another agent.
    3. The end_invocation is set to true by any callbacks or tools.

  A step:
    1. Calls the LLM only once and yields its response.
    2. Calls the tools and yields their responses if requested.

  The summarization of the function response is considered another step, since
  it is another llm call.
  A step ends when it's done calling llm and tools, or if the end_invocation
  is set to true at any time.

  ```
     ┌─────────────────────── invocation ──────────────────────────┐
     ┌──────────── llm_agent_call_1 ────────────┐ ┌─ agent_call_2 ─┐
     ┌──── step_1 ────────┐ ┌───── step_2 ──────┐
     [call_llm] [call_tool] [call_llm] [transfer]
  ```
  """

  model_config = ConfigDict(
      arbitrary_types_allowed=True,
      extra="forbid",
  )
  """The pydantic model config."""

  artifact_service: Optional[BaseArtifactService] = None
  session_service: BaseSessionService
  memory_service: Optional[BaseMemoryService] = None
  credential_service: Optional[BaseCredentialService] = None
  context_cache_config: Optional[ContextCacheConfig] = None

  invocation_id: str
  """The id of this invocation context. Readonly."""
  branch: Optional[str] = None
  """The branch of the invocation context.

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