Langgraph react agent

LangGraph ReAct Agent implementation.

A ReAct agent template built on LangGraph that can use either lm_invoker or LangChain BaseChatModel.

Authors

Christian Trisno Sen Long Chen (christian.t.s.l.chen@gdplabs.id) Fachriza Adhiatma (fachriza.d.adhiatma@gdplabs.id)

LangChainAgent(name, instruction=DEFAULT_INSTRUCTION, model=None, tools=None, agents=None, description=None, thread_id_key='thread_id', event_emitter=None, **kwargs)

Bases: LangGraphReactAgent

Alias for LangGraphReactAgent.

Initialize the LangGraph ReAct Agent.

Parameters:

Name	Type	Description	Default
name	str	The name of the agent.	required
instruction	str	The system instruction for the agent.	DEFAULT_INSTRUCTION
model	BaseChatModel | str | Any | None	The model to use (lm_invoker, LangChain model, string, etc.).	None
tools	Sequence[BaseTool] | None	Sequence of LangChain tools available to the agent.	None
agents	Sequence[Any] | None	Optional sequence of sub-agents for delegation (coordinator mode).	None
description	str | None	Human-readable description of the agent.	None
thread_id_key	str	Key for thread ID in configuration.	'thread_id'
event_emitter	EventEmitter | None	Optional event emitter for streaming updates.	None
**kwargs	Any	Additional keyword arguments passed to BaseLangGraphAgent.	{}

LangGraphAgent(name, instruction=DEFAULT_INSTRUCTION, model=None, tools=None, agents=None, description=None, thread_id_key='thread_id', event_emitter=None, **kwargs)

Bases: LangGraphReactAgent

Alias for LangGraphReactAgent.

Initialize the LangGraph ReAct Agent.

Parameters:

Name	Type	Description	Default
name	str	The name of the agent.	required
instruction	str	The system instruction for the agent.	DEFAULT_INSTRUCTION
model	BaseChatModel | str | Any | None	The model to use (lm_invoker, LangChain model, string, etc.).	None
tools	Sequence[BaseTool] | None	Sequence of LangChain tools available to the agent.	None
agents	Sequence[Any] | None	Optional sequence of sub-agents for delegation (coordinator mode).	None
description	str | None	Human-readable description of the agent.	None
thread_id_key	str	Key for thread ID in configuration.	'thread_id'
event_emitter	EventEmitter | None	Optional event emitter for streaming updates.	None
**kwargs	Any	Additional keyword arguments passed to BaseLangGraphAgent.	{}

LangGraphReactAgent(name, instruction=DEFAULT_INSTRUCTION, model=None, tools=None, agents=None, description=None, thread_id_key='thread_id', event_emitter=None, **kwargs)

Bases: BaseLangGraphAgent

A ReAct agent template built on LangGraph.

This agent can use either: - An LMInvoker (if self.lm_invoker is set by BaseAgent) - A LangChain BaseChatModel (if self.model is set by BaseAgent)

The graph structure follows the standard ReAct pattern: agent -> tools -> agent (loop) -> END

Initialize the LangGraph ReAct Agent.

Parameters:

Name	Type	Description	Default
name	str	The name of the agent.	required
instruction	str	The system instruction for the agent.	DEFAULT_INSTRUCTION
model	BaseChatModel | str | Any | None	The model to use (lm_invoker, LangChain model, string, etc.).	None
tools	Sequence[BaseTool] | None	Sequence of LangChain tools available to the agent.	None
agents	Sequence[Any] | None	Optional sequence of sub-agents for delegation (coordinator mode).	None
description	str | None	Human-readable description of the agent.	None
thread_id_key	str	Key for thread ID in configuration.	'thread_id'
event_emitter	EventEmitter | None	Optional event emitter for streaming updates.	None
**kwargs	Any	Additional keyword arguments passed to BaseLangGraphAgent.	{}

define_graph(graph_builder)

Define the ReAct agent graph structure.

Parameters:

Name	Type	Description	Default
graph_builder	StateGraph	The StateGraph builder to define the graph structure.	required

Returns:

Type	Description
CompiledStateGraph	Compiled LangGraph ready for execution.

ReactAgentState

Bases: TypedDict

State schema for the ReAct agent.

Includes messages, step tracking, optional event emission support, artifacts, references, and metadata.