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@langchain/langgraph

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LangGraph

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import { BaseChatModel } from "@langchain/core/language_models/chat_models"; import { LanguageModelLike } from "@langchain/core/language_models/base"; import { BaseMessage, BaseMessageLike, SystemMessage } from "@langchain/core/messages"; import { Runnable, RunnableToolLike, type RunnableLike } from "@langchain/core/runnables"; import { DynamicTool, StructuredToolInterface } from "@langchain/core/tools"; import { All, BaseCheckpointSaver, BaseStore } from "@langchain/langgraph-checkpoint"; import { z } from "zod"; import { type CompiledStateGraph, AnnotationRoot } from "../graph/index.js"; import { MessagesAnnotation } from "../graph/messages_annotation.js"; import { ToolNode } from "./tool_node.js"; import { LangGraphRunnableConfig } from "../pregel/runnable_types.js"; import { Messages } from "../graph/message.js"; import { START } from "../constants.js"; export interface AgentState<StructuredResponseType extends Record<string, any> = Record<string, any>> { messages: BaseMessage[]; structuredResponse: StructuredResponseType; } export type N = typeof START | "agent" | "tools"; export type StructuredResponseSchemaAndPrompt<StructuredResponseType> = { prompt: string; schema: z.ZodType<StructuredResponseType> | Record<string, any>; }; type ServerTool = Record<string, unknown>; type ClientTool = StructuredToolInterface | DynamicTool | RunnableToolLike; interface ConfigurableModelInterface { _queuedMethodOperations: Record<string, any>; _model: () => Promise<BaseChatModel>; } export declare function _shouldBindTools(llm: LanguageModelLike, tools: (ClientTool | ServerTool)[]): Promise<boolean>; export declare function _getModel(llm: LanguageModelLike | ConfigurableModelInterface): Promise<BaseChatModel>; export type Prompt = SystemMessage | string | ((state: typeof MessagesAnnotation.State, config: LangGraphRunnableConfig) => BaseMessageLike[]) | ((state: typeof MessagesAnnotation.State, config: LangGraphRunnableConfig) => Promise<BaseMessageLike[]>) | Runnable; /** @deprecated Use Prompt instead. */ export type StateModifier = Prompt; /** @deprecated Use Prompt instead. */ export type MessageModifier = SystemMessage | string | ((messages: BaseMessage[]) => BaseMessage[]) | ((messages: BaseMessage[]) => Promise<BaseMessage[]>) | Runnable; export declare const createReactAgentAnnotation: <T extends Record<string, any> = Record<string, any>>() => AnnotationRoot<{ messages: import("../web.js").BinaryOperatorAggregate<BaseMessage[], Messages>; structuredResponse: { (): import("../web.js").LastValue<T>; (annotation: import("../web.js").SingleReducer<T, T>): import("../web.js").BinaryOperatorAggregate<T, T>; Root: <S extends import("../web.js").StateDefinition>(sd: S) => AnnotationRoot<S>; }; }>; declare const PreHookAnnotation: AnnotationRoot<{ llmInputMessages: import("../web.js").BinaryOperatorAggregate<BaseMessage[], Messages>; }>; type PreHookAnnotation = typeof PreHookAnnotation; export type CreateReactAgentParams<A extends AnnotationRoot<any> = AnnotationRoot<any>, StructuredResponseType = Record<string, any>> = { /** The chat model that can utilize OpenAI-style tool calling. */ llm: LanguageModelLike; /** A list of tools or a ToolNode. */ tools: ToolNode | (ServerTool | ClientTool)[]; /** * @deprecated Use prompt instead. */ messageModifier?: MessageModifier; /** * @deprecated Use prompt instead. */ stateModifier?: StateModifier; /** * An optional prompt for the LLM. This takes full graph state BEFORE the LLM is called and prepares the input to LLM. * * Can take a few different forms: * * - str: This is converted to a SystemMessage and added to the beginning of the list of messages in state["messages"]. * - SystemMessage: this is added to the beginning of the list of messages in state["messages"]. * - Function: This function should take in full graph state and the output is then passed to the language model. * - Runnable: This runnable should take in full graph state and the output is then passed to the language model. * * Note: * Prior to `v0.2.46`, the prompt was set using `stateModifier` / `messagesModifier` parameters. * This is now deprecated and will be removed in a future release. */ prompt?: Prompt; stateSchema?: A; /** An optional checkpoint saver to persist the agent's state. */ checkpointSaver?: BaseCheckpointSaver; /** An optional checkpoint saver to persist the agent's state. Alias of "checkpointSaver". */ checkpointer?: BaseCheckpointSaver; /** An optional list of node names to interrupt before running. */ interruptBefore?: N[] | All; /** An optional list of node names to interrupt after running. */ interruptAfter?: N[] | All; store?: BaseStore; /** * An optional schema for the final agent output. * * If provided, output will be formatted to match the given schema and returned in the 'structuredResponse' state key. * If not provided, `structuredResponse` will not be present in the output state. * * Can be passed in as: * - Zod schema * - JSON schema * - { prompt, schema }, where schema is one of the above. * The prompt will be used together with the model that is being used to generate the structured response. * * @remarks * **Important**: `responseFormat` requires the model to support `.withStructuredOutput()`. * * **Note**: The graph will make a separate call to the LLM to generate the structured response after the agent loop is finished. * This is not the only strategy to get structured responses, see more options in [this guide](https://langchain-ai.github.io/langgraph/how-tos/react-agent-structured-output/). */ responseFormat?: z.ZodType<StructuredResponseType> | StructuredResponseSchemaAndPrompt<StructuredResponseType> | Record<string, any>; /** * An optional name for the agent. */ name?: string; /** * Use to specify how to expose the agent name to the underlying supervisor LLM. - undefined: Relies on the LLM provider {@link AIMessage#name}. Currently, only OpenAI supports this. - `"inline"`: Add the agent name directly into the content field of the {@link AIMessage} using XML-style tags. Example: `"How can I help you"` -> `"<name>agent_name</name><content>How can I help you?</content>"` */ includeAgentName?: "inline" | undefined; /** * An optional node to add before the `agent` node (i.e., the node that calls the LLM). * Useful for managing long message histories (e.g., message trimming, summarization, etc.). */ preModelHook?: RunnableLike<A["State"] & PreHookAnnotation["State"], A["Update"] & PreHookAnnotation["Update"], LangGraphRunnableConfig>; /** * An optional node to add after the `agent` node (i.e., the node that calls the LLM). * Useful for implementing human-in-the-loop, guardrails, validation, or other post-processing. */ postModelHook?: RunnableLike<A["State"], A["Update"], LangGraphRunnableConfig>; }; /** * Creates a StateGraph agent that relies on a chat model utilizing tool calling. * * @example * ```ts * import { ChatOpenAI } from "@langchain/openai"; * import { tool } from "@langchain/core/tools"; * import { z } from "zod"; * import { createReactAgent } from "@langchain/langgraph/prebuilt"; * * const model = new ChatOpenAI({ * model: "gpt-4o", * }); * * const getWeather = tool((input) => { * if (["sf", "san francisco"].includes(input.location.toLowerCase())) { * return "It's 60 degrees and foggy."; * } else { * return "It's 90 degrees and sunny."; * } * }, { * name: "get_weather", * description: "Call to get the current weather.", * schema: z.object({ * location: z.string().describe("Location to get the weather for."), * }) * }) * * const agent = createReactAgent({ llm: model, tools: [getWeather] }); * * const inputs = { * messages: [{ role: "user", content: "what is the weather in SF?" }], * }; * * const stream = await agent.stream(inputs, { streamMode: "values" }); * * for await (const { messages } of stream) { * console.log(messages); * } * // Returns the messages in the state at each step of execution * ``` */ export declare function createReactAgent<A extends AnnotationRoot<any> = typeof MessagesAnnotation, StructuredResponseFormat extends Record<string, any> = Record<string, any>>(params: CreateReactAgentParams<A, StructuredResponseFormat>): CompiledStateGraph<A["State"], A["Update"], any, typeof MessagesAnnotation.spec & A["spec"], ReturnType<typeof createReactAgentAnnotation<StructuredResponseFormat>>["spec"] & A["spec"]>; export {};