react

type Agent struct {
	// contains filtered or unexported fields
}

type AgentConfig struct {
	// ToolCallingModel is the chat model to be used for handling user messages with tool calling capability.
	// This is the recommended model field to use.
	ToolCallingModel model.ToolCallingChatModel

	// Deprecated: Use ToolCallingModel instead.
	Model model.ChatModel

	// ToolsConfig is the config for tools node.
	ToolsConfig compose.ToolsNodeConfig

	// MessageModifier.
	// modify the input messages before the model is called, it's useful when you want to add some system prompt or other messages.
	MessageModifier MessageModifier

	// MessageRewriter modifies message in the state, before the ChatModel is called.
	// It takes the messages stored accumulated in state, modify them, and put the modified version back into state.
	// Useful for compressing message history to fit the model context window,
	// or if you want to make changes to messages that take effect across multiple model calls.
	// NOTE: if both MessageModifier and MessageRewriter are set, MessageRewriter will be called before MessageModifier.
	MessageRewriter MessageModifier

	// MaxStep.
	// default 12 of steps in pregel (node num + 10).
	MaxStep int `json:"max_step"`

	// Tools that will make agent return directly when the tool is called.
	// When multiple tools are called and more than one tool is in the return directly list, only the first one will be returned.
	ToolReturnDirectly map[string]struct{}

	// StreamToolCallChecker is a function to determine whether the model's streaming output contains tool calls.
	// Different models have different ways of outputting tool calls in streaming mode:
	// - Some models (like OpenAI) output tool calls directly
	// - Others (like Claude) output text first, then tool calls
	// This handler allows custom logic to check for tool calls in the stream.
	// It should return:
	// - true if the output contains tool calls and agent should continue processing
	// - false if no tool calls and agent should stop
	// Note: This field only needs to be configured when using streaming mode
	// Note: The handler MUST close the modelOutput stream before returning
	// Optional. By default, it checks if the first chunk contains tool calls.
	// Note: The default implementation does not work well with Claude, which typically outputs tool calls after text content.
	// Note: If your ChatModel doesn't output tool calls first, you can try adding prompts to constrain the model from generating extra text during the tool call.
	StreamToolCallChecker func(ctx context.Context, modelOutput *schema.StreamReader[*schema.Message]) (bool, error)

	// GraphName is the graph name of the ReAct Agent.
	// Optional. Default `ReActAgent`.
	GraphName string
	// ModelNodeName is the node name of the model node in the ReAct Agent graph.
	// Optional. Default `ChatModel`.
	ModelNodeName string
	// ToolsNodeName is the node name of the tools node in the ReAct Agent graph.
	// Optional. Default `Tools`.
	ToolsNodeName string
}

type Iterator[T any] struct {
	// contains filtered or unexported fields
}

type MessageFuture interface {
	// GetMessages returns an iterator for retrieving messages generated during "agent.Generate" calls.
	GetMessages() *Iterator[*schema.Message]

	// GetMessageStreams returns an iterator for retrieving streaming messages generated during "agent.Stream" calls.
	GetMessageStreams() *Iterator[*schema.StreamReader[*schema.Message]]
}

type MessageModifier func(ctx context.Context, input []*schema.Message) []*schema.Message