openhands.sdk.event

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class ActionEvent

Bases: LLMConvertibleEvent

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Properties

• action: Action | None
• kind: Literal[‘ActionEvent’]
• llm_response_id: str
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• reasoning_content: str | None
• responses_reasoning_item: ReasoningItemModel | None
• security_risk: SecurityRisk
• source: Literal[‘agent’, ‘user’, ‘environment’]
• thinking_blocks: list[ThinkingBlock | RedactedThinkingBlock]
• thought: Sequence[TextContent]
• tool_call: MessageToolCall
• tool_call_id: str
• tool_name: str
• visualize: Text Return Rich Text representation of this action event.

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Methods

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to_llm_message()

Individual message - may be incomplete for multi-action batches

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class AgentErrorEvent

Bases: ObservationBaseEvent Error triggered by the agent. Note: This event should not contain model “thought” or “reasoning_content”. It represents an error produced by the agent/scaffold, not model output.

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Properties

• error: str
• kind: Literal[‘AgentErrorEvent’]
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]
• visualize: Text Return Rich Text representation of this agent error event.

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Methods

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to_llm_message()

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class Condensation

Bases: Event This action indicates a condensation of the conversation history is happening.

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Properties

• forgotten_event_ids: list[str]
• kind: Literal[‘Condensation’]
• llm_response_id: str
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]
• summary: str | None
• summary_offset: int | None
• visualize: Text Return Rich Text representation of this event. This is a fallback implementation for unknown event types. Subclasses should override this method to provide specific visualization.

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class CondensationRequest

Bases: Event This action is used to request a condensation of the conversation history.

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Properties

• kind: Literal[‘CondensationRequest’]
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]

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Methods

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action

The action type, namely ActionType.CONDENSATION_REQUEST.

• Type: str

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class CondensationSummaryEvent

Bases: LLMConvertibleEvent This event represents a summary generated by a condenser.

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Properties

• kind: Literal[‘CondensationSummaryEvent’]
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]
• summary: str The summary text.

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Methods

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to_llm_message()

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class ConversationStateUpdateEvent

Bases: Event Event that contains conversation state updates. This event is sent via websocket whenever the conversation state changes, allowing remote clients to stay in sync without making REST API calls. All fields are serialized versions of the corresponding ConversationState fields to ensure compatibility with websocket transmission.

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Properties

• key: str
• kind: Literal[‘ConversationStateUpdateEvent’]
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]
• value: Any

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Methods

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classmethod from_conversation_state()

Create a state update event from a ConversationState object. This creates an event containing a snapshot of important state fields.

• Parameters:
  • state – The ConversationState to serialize
  • conversation_id – The conversation ID for the event
• Returns: A ConversationStateUpdateEvent with serialized state data

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classmethod validate_key()

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classmethod validate_value()

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class Event

Bases: DiscriminatedUnionMixin, ABC Base class for all events.

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Properties

• id: str
• kind: str
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]
• timestamp: str
• visualize: Text Return Rich Text representation of this event. This is a fallback implementation for unknown event types. Subclasses should override this method to provide specific visualization.

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class LLMConvertibleEvent

Bases: Event, ABC Base class for events that can be converted to LLM messages.

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Properties

• id: EventID
• kind: str
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: SourceType
• timestamp: str

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Methods

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static events_to_messages()

Convert event stream to LLM message stream, handling multi-action batches

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abstractmethod to_llm_message()

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class MessageEvent

Bases: LLMConvertibleEvent Message from either agent or user. This is originally the “MessageAction”, but it suppose not to be tool call.

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Properties

• activated_skills: list[str]
• extended_content: list[TextContent]
• id: EventID
• kind: Literal[‘MessageEvent’]
• llm_message: Message
• llm_response_id: str | None
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• reasoning_content: str
• source: Literal[‘agent’, ‘user’, ‘environment’]
• thinking_blocks: Sequence[ThinkingBlock | RedactedThinkingBlock] Return the Anthropic thinking blocks from the LLM message.
• timestamp: str
• visualize: Text Return Rich Text representation of this message event.

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Methods

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to_llm_message()

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class ObservationBaseEvent

Bases: LLMConvertibleEvent Base class for anything as a response to a tool call. Examples include tool execution, error, user reject.

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Properties

• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]
• tool_call_id: str
• tool_name: str

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class ObservationEvent

Bases: ObservationBaseEvent

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Properties

• action_id: str
• kind: Literal[‘ObservationEvent’]
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• observation: Observation
• visualize: Text Return Rich Text representation of this observation event.

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Methods

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to_llm_message()

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class PauseEvent

Bases: Event Event indicating that the agent execution was paused by user request.

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Properties

• kind: Literal[‘PauseEvent’]
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]
• visualize: Text Return Rich Text representation of this pause event.

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class SystemPromptEvent

Bases: LLMConvertibleEvent System prompt added by the agent.

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Properties

• kind: Literal[‘SystemPromptEvent’]
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• source: Literal[‘agent’, ‘user’, ‘environment’]
• system_prompt: TextContent
• tools: list[ChatCompletionToolParam]
• visualize: Text Return Rich Text representation of this system prompt event.

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Methods

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to_llm_message()

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class UserRejectObservation

Bases: ObservationBaseEvent Observation when user rejects an action in confirmation mode.

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Properties

• action_id: str
• kind: Literal[‘UserRejectObservation’]
• model_config: ClassVar[ConfigDict] = (configuration object) Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].
• rejection_reason: str
• visualize: Text Return Rich Text representation of this user rejection event.

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Methods

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to_llm_message()