langchain
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Typescript bindings for langchain
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TypeScript
import { ResponseFormatUndefined } from "./responses.js";
import { InvokeConfiguration, StreamConfiguration } from "./runtime.js";
import { AgentMiddleware, AnyAnnotationRoot, InferContextInput, InferMiddlewareContextInputs, InferMiddlewareInputStates, InferMiddlewareStates, InferSchemaInput, ToAnnotationRoot } from "./middleware/types.js";
import { AgentTypeConfig, BuiltInState, CreateAgentParams, ToolsToMessageToolSet, UserInput } from "./types.js";
import { MessageStructure } from "@langchain/core/messages";
import { Runnable, RunnableConfig } from "@langchain/core/runnables";
import { IterableReadableStream } from "@langchain/core/utils/stream";
import { ClientTool, ServerTool } from "@langchain/core/tools";
import { Command, CompiledStateGraph, GetStateOptions, LangGraphRunnableConfig, StateGraph, StreamMode, StreamOutputMap } from "@langchain/langgraph";
import { InteropZodObject } from "@langchain/core/utils/types";
import { CheckpointListOptions } from "@langchain/langgraph-checkpoint";
import { StreamEvent } from "@langchain/core/tracers/log_stream";
//#region src/agents/ReactAgent.d.ts
type MergedAgentState<Types extends AgentTypeConfig> = InferSchemaInput<Types["State"]> & (Types["Response"] extends ResponseFormatUndefined ? Omit<BuiltInState<MessageStructure<ToolsToMessageToolSet<Types["Tools"]>>>, "jumpTo"> : Omit<BuiltInState<MessageStructure<ToolsToMessageToolSet<Types["Tools"]>>>, "jumpTo"> & {
structuredResponse: Types["Response"];
}) & InferMiddlewareStates<Types["Middleware"]>;
type InvokeStateParameter<Types extends AgentTypeConfig> = (UserInput<Types["State"]> & InferMiddlewareInputStates<Types["Middleware"]>) | Command<any, any, any> | null;
type AgentGraph<Types extends AgentTypeConfig> = CompiledStateGraph<any, any, any, any, MergedAgentState<Types>, ToAnnotationRoot<Types["Context"] extends AnyAnnotationRoot | InteropZodObject ? Types["Context"] : AnyAnnotationRoot>["spec"], unknown>;
/**
* ReactAgent is a production-ready ReAct (Reasoning + Acting) agent that combines
* language models with tools and middleware.
*
* The agent is parameterized by a single type bag `Types` that encapsulates all
* type information:
*
* @typeParam Types - An {@link AgentTypeConfig} that bundles:
* - `Response`: The structured response type
* - `State`: The custom state schema type
* - `Context`: The context schema type
* - `Middleware`: The middleware array type
* - `Tools`: The combined tools type from agent and middleware
*
* @example
* ```typescript
* // Using the type bag pattern
* type MyTypes = AgentTypeConfig<
* { name: string }, // Response
* typeof myState, // State
* typeof myContext, // Context
* typeof middleware, // Middleware
* typeof tools // Tools
* >;
*
* const agent: ReactAgent<MyTypes> = createAgent({ ... });
* ```
*/
declare class ReactAgent<Types extends AgentTypeConfig = AgentTypeConfig<Record<string, any>, undefined, AnyAnnotationRoot, readonly AgentMiddleware[], readonly (ClientTool | ServerTool)[]>> {
#private;
options: CreateAgentParams<Types["Response"], Types["State"], Types["Context"]>;
/**
* Type marker for extracting the AgentTypeConfig from a ReactAgent instance.
* This is a phantom property used only for type inference.
* @internal
*/
readonly "~agentTypes": Types;
constructor(options: CreateAgentParams<Types["Response"], Types["State"], Types["Context"]>);
/**
* Get the compiled {@link https://docs.langchain.com/oss/javascript/langgraph/use-graph-api | StateGraph}.
*/
get graph(): AgentGraph<Types>;
/**
* Executes the agent with the given state and returns the final state after all processing.
*
* This method runs the agent's entire workflow synchronously, including:
* - Processing the input messages through any configured middleware
* - Calling the language model to generate responses
* - Executing any tool calls made by the model
* - Running all middleware hooks (beforeModel, afterModel, etc.)
*
* @param state - The initial state for the agent execution. Can be:
* - An object containing `messages` array and any middleware-specific state properties
* - A Command object for more advanced control flow
*
* @param config - Optional runtime configuration including:
* @param config.context - The context for the agent execution.
* @param config.configurable - LangGraph configuration options like `thread_id`, `run_id`, etc.
* @param config.store - The store for the agent execution for persisting state, see more in {@link https://docs.langchain.com/oss/javascript/langgraph/memory#memory-storage | Memory storage}.
* @param config.signal - An optional {@link https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal | `AbortSignal`} for the agent execution.
* @param config.recursionLimit - The recursion limit for the agent execution.
*
* @returns A Promise that resolves to the final agent state after execution completes.
* The returned state includes:
* - a `messages` property containing an array with all messages (input, AI responses, tool calls/results)
* - a `structuredResponse` property containing the structured response (if configured)
* - all state values defined in the middleware
*
* @example
* ```typescript
* const agent = new ReactAgent({
* llm: myModel,
* tools: [calculator, webSearch],
* responseFormat: z.object({
* weather: z.string(),
* }),
* });
*
* const result = await agent.invoke({
* messages: [{ role: "human", content: "What's the weather in Paris?" }]
* });
*
* console.log(result.structuredResponse.weather); // outputs: "It's sunny and 75°F."
* ```
*/
invoke(state: InvokeStateParameter<Types>, config?: InvokeConfiguration<InferContextInput<Types["Context"] extends AnyAnnotationRoot | InteropZodObject ? Types["Context"] : AnyAnnotationRoot> & InferMiddlewareContextInputs<Types["Middleware"]>>): Promise<MergedAgentState<Types>>;
/**
* Executes the agent with streaming, returning an async iterable of state updates as they occur.
*
* This method runs the agent's workflow similar to `invoke`, but instead of waiting for
* completion, it streams high-level state updates in real-time. This allows you to:
* - Display intermediate results to users as they're generated
* - Monitor the agent's progress through each step
* - React to state changes as nodes complete
*
* For more granular event-level streaming (like individual LLM tokens), use `streamEvents` instead.
*
* @param state - The initial state for the agent execution. Can be:
* - An object containing `messages` array and any middleware-specific state properties
* - A Command object for more advanced control flow
*
* @param config - Optional runtime configuration including:
* @param config.context - The context for the agent execution.
* @param config.configurable - LangGraph configuration options like `thread_id`, `run_id`, etc.
* @param config.store - The store for the agent execution for persisting state, see more in {@link https://docs.langchain.com/oss/javascript/langgraph/memory#memory-storage | Memory storage}.
* @param config.signal - An optional {@link https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal | `AbortSignal`} for the agent execution.
* @param config.streamMode - The streaming mode for the agent execution, see more in {@link https://docs.langchain.com/oss/javascript/langgraph/streaming#supported-stream-modes | Supported stream modes}.
* @param config.recursionLimit - The recursion limit for the agent execution.
*
* @returns A Promise that resolves to an IterableReadableStream of state updates.
* Each update contains the current state after a node completes.
*
* @example
* ```typescript
* const agent = new ReactAgent({
* llm: myModel,
* tools: [calculator, webSearch]
* });
*
* const stream = await agent.stream({
* messages: [{ role: "human", content: "What's 2+2 and the weather in NYC?" }]
* });
*
* for await (const chunk of stream) {
* console.log(chunk); // State update from each node
* }
* ```
*/
stream<TStreamMode extends StreamMode | StreamMode[] | undefined, TEncoding extends "text/event-stream" | undefined>(state: InvokeStateParameter<Types>, config?: StreamConfiguration<InferContextInput<Types["Context"] extends AnyAnnotationRoot | InteropZodObject ? Types["Context"] : AnyAnnotationRoot> & InferMiddlewareContextInputs<Types["Middleware"]>, TStreamMode, TEncoding>): Promise<IterableReadableStream<StreamOutputMap<TStreamMode, false, MergedAgentState<Types>, MergedAgentState<Types>, string, unknown, unknown, TEncoding>>>;
/**
* Visualize the graph as a PNG image.
* @param params - Parameters for the drawMermaidPng method.
* @param params.withStyles - Whether to include styles in the graph.
* @param params.curveStyle - The style of the graph's curves.
* @param params.nodeColors - The colors of the graph's nodes.
* @param params.wrapLabelNWords - The maximum number of words to wrap in a node's label.
* @param params.backgroundColor - The background color of the graph.
* @returns PNG image as a buffer
*/
drawMermaidPng(params?: {
withStyles?: boolean;
curveStyle?: string;
nodeColors?: Record<string, string>;
wrapLabelNWords?: number;
backgroundColor?: string;
}): Promise<Uint8Array<ArrayBuffer>>;
/**
* Draw the graph as a Mermaid string.
* @param params - Parameters for the drawMermaid method.
* @param params.withStyles - Whether to include styles in the graph.
* @param params.curveStyle - The style of the graph's curves.
* @param params.nodeColors - The colors of the graph's nodes.
* @param params.wrapLabelNWords - The maximum number of words to wrap in a node's label.
* @param params.backgroundColor - The background color of the graph.
* @returns Mermaid string
*/
drawMermaid(params?: {
withStyles?: boolean;
curveStyle?: string;
nodeColors?: Record<string, string>;
wrapLabelNWords?: number;
backgroundColor?: string;
}): Promise<string>;
/**
* The following are internal methods to enable support for LangGraph Platform.
* They are not part of the createAgent public API.
*
* Note: we intentionally return as `never` to avoid type errors due to type inference.
*/
/**
* @internal
*/
streamEvents(state: InvokeStateParameter<Types>, config?: StreamConfiguration<InferContextInput<Types["Context"] extends AnyAnnotationRoot | InteropZodObject ? Types["Context"] : AnyAnnotationRoot> & InferMiddlewareContextInputs<Types["Middleware"]>, StreamMode | StreamMode[] | undefined, "text/event-stream" | undefined> & {
version?: "v1" | "v2";
}, streamOptions?: Parameters<Runnable["streamEvents"]>[2]): IterableReadableStream<StreamEvent>;
/**
* @internal
*/
getGraphAsync(config?: RunnableConfig): never;
/**
* @internal
*/
getState(config: RunnableConfig, options?: GetStateOptions): never;
/**
* @internal
*/
getStateHistory(config: RunnableConfig, options?: CheckpointListOptions): never;
/**
* @internal
*/
getSubgraphs(namespace?: string, recurse?: boolean): never;
/**
* @internal
*/
getSubgraphAsync(namespace?: string, recurse?: boolean): never;
/**
* @internal
*/
updateState(inputConfig: LangGraphRunnableConfig, values: Record<string, unknown> | unknown, asNode?: string): never;
/**
* @internal
*/
get builder(): StateGraph<unknown, any, any, any, any, MergedAgentState<Types>, ToAnnotationRoot<Types["Context"] extends AnyAnnotationRoot | InteropZodObject ? Types["Context"] : AnyAnnotationRoot>["spec"], unknown, unknown, unknown>;
}
//#endregion
export { ReactAgent };
//# sourceMappingURL=ReactAgent.d.ts.map