@langchain/core
Version:
Core LangChain.js abstractions and schemas
1,767 lines • 66.4 kB
JavaScript
const require_utils = require("../tools/utils.cjs");
const require_load_serializable = require("../load/serializable.cjs");
const require_utils_uuid_index = require("../utils/uuid/index.cjs");
const require_index = require("../singletons/async_local_storage/index.cjs");
require("../singletons/index.cjs");
const require_config = require("./config.cjs");
const require_signal = require("../utils/signal.cjs");
const require_utils_stream = require("../utils/stream.cjs");
const require_tracers_log_stream = require("../tracers/log_stream.cjs");
const require_event_stream = require("../tracers/event_stream.cjs");
const require_index$1 = require("../utils/p-retry/index.cjs");
const require_utils_async_caller = require("../utils/async_caller.cjs");
const require_root_listener = require("../tracers/root_listener.cjs");
const require_utils$1 = require("./utils.cjs");
const require_zod = require("../utils/types/zod.cjs");
const require_runnables_graph = require("./graph.cjs");
const require_wrappers = require("./wrappers.cjs");
const require_iter = require("./iter.cjs");
let langsmith_singletons_traceable = require("langsmith/singletons/traceable");
let zod_v3 = require("zod/v3");
//#region src/runnables/base.ts
function _coerceToDict(value, defaultKey) {
return value && !Array.isArray(value) && !(value instanceof Date) && typeof value === "object" ? value : { [defaultKey]: value };
}
/**
* A Runnable is a generic unit of work that can be invoked, batched, streamed, and/or
* transformed.
*/
var Runnable = class extends require_load_serializable.Serializable {
lc_runnable = true;
name;
getName(suffix) {
const name = this.name ?? this.constructor.lc_name() ?? this.constructor.name;
return suffix ? `${name}${suffix}` : name;
}
/**
* Add retry logic to an existing runnable.
* @param fields.stopAfterAttempt The number of attempts to retry.
* @param fields.onFailedAttempt A function that is called when a retry fails.
* @returns A new RunnableRetry that, when invoked, will retry according to the parameters.
*/
withRetry(fields) {
return new RunnableRetry({
bound: this,
kwargs: {},
config: {},
maxAttemptNumber: fields?.stopAfterAttempt,
...fields
});
}
/**
* Bind config to a Runnable, returning a new Runnable.
* @param config New configuration parameters to attach to the new runnable.
* @returns A new RunnableBinding with a config matching what's passed.
*/
withConfig(config) {
return new RunnableBinding({
bound: this,
config,
kwargs: {}
});
}
/**
* Create a new runnable from the current one that will try invoking
* other passed fallback runnables if the initial invocation fails.
* @param fields.fallbacks Other runnables to call if the runnable errors.
* @returns A new RunnableWithFallbacks.
*/
withFallbacks(fields) {
const fallbacks = Array.isArray(fields) ? fields : fields.fallbacks;
return new RunnableWithFallbacks({
runnable: this,
fallbacks
});
}
_getOptionsList(options, length = 0) {
if (Array.isArray(options) && options.length !== length) throw new Error(`Passed "options" must be an array with the same length as the inputs, but got ${options.length} options for ${length} inputs`);
if (Array.isArray(options)) return options.map(require_config.ensureConfig);
if (length > 1 && !Array.isArray(options) && options.runId) {
console.warn("Provided runId will be used only for the first element of the batch.");
const subsequent = Object.fromEntries(Object.entries(options).filter(([key]) => key !== "runId"));
return Array.from({ length }, (_, i) => require_config.ensureConfig(i === 0 ? options : subsequent));
}
return Array.from({ length }, () => require_config.ensureConfig(options));
}
async batch(inputs, options, batchOptions) {
const configList = this._getOptionsList(options ?? {}, inputs.length);
const caller = new require_utils_async_caller.AsyncCaller({
maxConcurrency: configList[0]?.maxConcurrency ?? batchOptions?.maxConcurrency,
onFailedAttempt: (e) => {
throw e;
}
});
const batchCalls = inputs.map((input, i) => caller.call(async () => {
try {
return await this.invoke(input, configList[i]);
} catch (e) {
if (batchOptions?.returnExceptions) return e;
throw e;
}
}));
return Promise.all(batchCalls);
}
/**
* Default streaming implementation.
* Subclasses should override this method if they support streaming output.
* @param input
* @param options
*/
async *_streamIterator(input, options) {
yield this.invoke(input, options);
}
/**
* Stream output in chunks.
* @param input
* @param options
* @returns A readable stream that is also an iterable.
*/
async stream(input, options) {
const config = require_config.ensureConfig(options);
const wrappedGenerator = new require_utils_stream.AsyncGeneratorWithSetup({
generator: this._streamIterator(input, config),
config
});
await wrappedGenerator.setup;
return require_utils_stream.IterableReadableStream.fromAsyncGenerator(wrappedGenerator);
}
_separateRunnableConfigFromCallOptions(options) {
let runnableConfig;
if (options === void 0) runnableConfig = require_config.ensureConfig(options);
else runnableConfig = require_config.ensureConfig({
callbacks: options.callbacks,
tags: options.tags,
metadata: options.metadata,
runName: options.runName,
configurable: options.configurable,
recursionLimit: options.recursionLimit,
maxConcurrency: options.maxConcurrency,
runId: options.runId,
timeout: options.timeout,
signal: options.signal
});
const callOptions = { ...options };
delete callOptions.callbacks;
delete callOptions.tags;
delete callOptions.metadata;
delete callOptions.runName;
delete callOptions.configurable;
delete callOptions.recursionLimit;
delete callOptions.maxConcurrency;
delete callOptions.runId;
delete callOptions.timeout;
delete callOptions.signal;
return [runnableConfig, callOptions];
}
async _callWithConfig(func, input, options) {
const config = require_config.ensureConfig(options);
const runManager = await (await require_config.getCallbackManagerForConfig(config))?.handleChainStart(this.toJSON(), _coerceToDict(input, "input"), config.runId, config?.runType, void 0, void 0, config?.runName ?? this.getName());
delete config.runId;
let output;
try {
output = await require_signal.raceWithSignal(func.call(this, input, config, runManager), config.signal);
} catch (e) {
await runManager?.handleChainError(e);
throw e;
}
await runManager?.handleChainEnd(_coerceToDict(output, "output"));
return output;
}
/**
* Internal method that handles batching and configuration for a runnable
* It takes a function, input values, and optional configuration, and
* returns a promise that resolves to the output values.
* @param func The function to be executed for each input value.
* @param input The input values to be processed.
* @param config Optional configuration for the function execution.
* @returns A promise that resolves to the output values.
*/
async _batchWithConfig(func, inputs, options, batchOptions) {
const optionsList = this._getOptionsList(options ?? {}, inputs.length);
const callbackManagers = await Promise.all(optionsList.map(require_config.getCallbackManagerForConfig));
const runManagers = await Promise.all(callbackManagers.map(async (callbackManager, i) => {
const handleStartRes = await callbackManager?.handleChainStart(this.toJSON(), _coerceToDict(inputs[i], "input"), optionsList[i].runId, optionsList[i].runType, void 0, void 0, optionsList[i].runName ?? this.getName());
delete optionsList[i].runId;
return handleStartRes;
}));
let outputs;
try {
outputs = await require_signal.raceWithSignal(func.call(this, inputs, optionsList, runManagers, batchOptions), optionsList?.[0]?.signal);
} catch (e) {
await Promise.all(runManagers.map((runManager) => runManager?.handleChainError(e)));
throw e;
}
await Promise.all(runManagers.map((runManager) => runManager?.handleChainEnd(_coerceToDict(outputs, "output"))));
return outputs;
}
/** @internal */
_concatOutputChunks(first, second) {
return require_utils_stream.concat(first, second);
}
/**
* Helper method to transform an Iterator of Input values into an Iterator of
* Output values, with callbacks.
* Use this to implement `stream()` or `transform()` in Runnable subclasses.
*/
async *_transformStreamWithConfig(inputGenerator, transformer, options) {
let finalInput;
let finalInputSupported = true;
let finalOutput;
let finalOutputSupported = true;
const config = require_config.ensureConfig(options);
const callbackManager_ = await require_config.getCallbackManagerForConfig(config);
const outerThis = this;
async function* wrapInputForTracing() {
for await (const chunk of inputGenerator) {
if (finalInputSupported) if (finalInput === void 0) finalInput = chunk;
else try {
finalInput = outerThis._concatOutputChunks(finalInput, chunk);
} catch {
finalInput = void 0;
finalInputSupported = false;
}
yield chunk;
}
}
let runManager;
try {
const pipe = await require_utils_stream.pipeGeneratorWithSetup(transformer.bind(this), wrapInputForTracing(), async () => callbackManager_?.handleChainStart(this.toJSON(), { input: "" }, config.runId, config.runType, void 0, void 0, config.runName ?? this.getName(), void 0, { lc_defers_inputs: true }), config.signal, config);
delete config.runId;
runManager = pipe.setup;
const streamEventsHandler = runManager?.handlers.find(require_event_stream.isStreamEventsHandler);
let iterator = pipe.output;
if (streamEventsHandler !== void 0 && runManager !== void 0) iterator = streamEventsHandler.tapOutputIterable(runManager.runId, iterator);
const streamLogHandler = runManager?.handlers.find(require_tracers_log_stream.isLogStreamHandler);
if (streamLogHandler !== void 0 && runManager !== void 0) iterator = streamLogHandler.tapOutputIterable(runManager.runId, iterator);
for await (const chunk of iterator) {
yield chunk;
if (finalOutputSupported) if (finalOutput === void 0) finalOutput = chunk;
else try {
finalOutput = this._concatOutputChunks(finalOutput, chunk);
} catch {
finalOutput = void 0;
finalOutputSupported = false;
}
}
} catch (e) {
await runManager?.handleChainError(e, void 0, void 0, void 0, { inputs: _coerceToDict(finalInput, "input") });
throw e;
}
await runManager?.handleChainEnd(finalOutput ?? {}, void 0, void 0, void 0, { inputs: _coerceToDict(finalInput, "input") });
}
getGraph(_) {
const graph = new require_runnables_graph.Graph();
const inputNode = graph.addNode({
name: `${this.getName()}Input`,
schema: zod_v3.z.any()
});
const runnableNode = graph.addNode(this);
const outputNode = graph.addNode({
name: `${this.getName()}Output`,
schema: zod_v3.z.any()
});
graph.addEdge(inputNode, runnableNode);
graph.addEdge(runnableNode, outputNode);
return graph;
}
/**
* Create a new runnable sequence that runs each individual runnable in series,
* piping the output of one runnable into another runnable or runnable-like.
* @param coerceable A runnable, function, or object whose values are functions or runnables.
* @returns A new runnable sequence.
*/
pipe(coerceable) {
return new RunnableSequence({
first: this,
last: _coerceToRunnable(coerceable)
});
}
/**
* Pick keys from the dict output of this runnable. Returns a new runnable.
*/
pick(keys) {
return this.pipe(new RunnablePick(keys));
}
/**
* Assigns new fields to the dict output of this runnable. Returns a new runnable.
*/
assign(mapping) {
return this.pipe(new RunnableAssign(new RunnableMap({ steps: mapping })));
}
/**
* Default implementation of transform, which buffers input and then calls stream.
* Subclasses should override this method if they can start producing output while
* input is still being generated.
* @param generator
* @param options
*/
async *transform(generator, options) {
let finalChunk;
for await (const chunk of generator) if (finalChunk === void 0) finalChunk = chunk;
else finalChunk = this._concatOutputChunks(finalChunk, chunk);
yield* this._streamIterator(finalChunk, require_config.ensureConfig(options));
}
/**
* Stream all output from a runnable, as reported to the callback system.
* This includes all inner runs of LLMs, Retrievers, Tools, etc.
* Output is streamed as Log objects, which include a list of
* jsonpatch ops that describe how the state of the run has changed in each
* step, and the final state of the run.
* The jsonpatch ops can be applied in order to construct state.
*
* @deprecated Use `.stream()` instead.
*
* @param input
* @param options
* @param streamOptions
*/
async *streamLog(input, options, streamOptions) {
const logStreamCallbackHandler = new require_tracers_log_stream.LogStreamCallbackHandler({
...streamOptions,
autoClose: false,
_schemaFormat: "original"
});
const config = require_config.ensureConfig(options);
yield* this._streamLog(input, logStreamCallbackHandler, config);
}
async *_streamLog(input, logStreamCallbackHandler, config) {
const { callbacks } = config;
if (callbacks === void 0) config.callbacks = [logStreamCallbackHandler];
else if (Array.isArray(callbacks)) config.callbacks = callbacks.concat([logStreamCallbackHandler]);
else {
const copiedCallbacks = callbacks.copy();
copiedCallbacks.addHandler(logStreamCallbackHandler, true);
config.callbacks = copiedCallbacks;
}
const runnableStreamPromise = this.stream(input, config);
async function consumeRunnableStream() {
try {
const runnableStream = await runnableStreamPromise;
for await (const chunk of runnableStream) {
const patch = new require_tracers_log_stream.RunLogPatch({ ops: [{
op: "add",
path: "/streamed_output/-",
value: chunk
}] });
await logStreamCallbackHandler.writer.write(patch);
}
} finally {
await logStreamCallbackHandler.writer.close();
}
}
const runnableStreamConsumePromise = consumeRunnableStream();
try {
for await (const log of logStreamCallbackHandler) yield log;
} finally {
await runnableStreamConsumePromise;
}
}
streamEvents(input, options, streamOptions) {
let stream;
if (options.version === "v1") stream = this._streamEventsV1(input, options, streamOptions);
else if (options.version === "v2") stream = this._streamEventsV2(input, options, streamOptions);
else throw new Error(`Only versions "v1" and "v2" of the schema are currently supported.`);
if (options.encoding === "text/event-stream") return require_wrappers.convertToHttpEventStream(stream);
else return require_utils_stream.IterableReadableStream.fromAsyncGenerator(stream);
}
async *_streamEventsV2(input, options, streamOptions) {
const eventStreamer = new require_event_stream.EventStreamCallbackHandler({
...streamOptions,
autoClose: false
});
const config = require_config.ensureConfig(options);
const runId = config.runId ?? require_utils_uuid_index.v7();
config.runId = runId;
const callbacks = config.callbacks;
if (callbacks === void 0) config.callbacks = [eventStreamer];
else if (Array.isArray(callbacks)) config.callbacks = callbacks.concat(eventStreamer);
else {
const copiedCallbacks = callbacks.copy();
copiedCallbacks.addHandler(eventStreamer, true);
config.callbacks = copiedCallbacks;
}
const abortController = new AbortController();
const outerThis = this;
async function consumeRunnableStream() {
let signal;
try {
if (config.signal) if ("any" in AbortSignal) signal = AbortSignal.any([abortController.signal, config.signal]);
else {
const composed = new AbortController();
config.signal.addEventListener("abort", () => composed.abort(), { once: true });
abortController.signal.addEventListener("abort", () => composed.abort(), { once: true });
signal = composed.signal;
}
else signal = abortController.signal;
const runnableStream = await outerThis.stream(input, {
...config,
signal
});
const tappedStream = eventStreamer.tapOutputIterable(runId, runnableStream);
for await (const _ of tappedStream) if (abortController.signal.aborted) break;
} finally {
await eventStreamer.finish();
}
}
const runnableStreamConsumePromise = consumeRunnableStream();
let firstEventSent = false;
let firstEventRunId;
try {
for await (const event of eventStreamer) {
if (!firstEventSent) {
event.data.input = input;
firstEventSent = true;
firstEventRunId = event.run_id;
yield event;
continue;
}
if (event.run_id === firstEventRunId && event.event.endsWith("_end")) {
if (event.data?.input) delete event.data.input;
}
yield event;
}
} finally {
abortController.abort();
await runnableStreamConsumePromise;
}
}
async *_streamEventsV1(input, options, streamOptions) {
let runLog;
let hasEncounteredStartEvent = false;
const config = require_config.ensureConfig(options);
const rootTags = config.tags ?? [];
const rootMetadata = config.metadata ?? {};
const rootName = config.runName ?? this.getName();
const logStreamCallbackHandler = new require_tracers_log_stream.LogStreamCallbackHandler({
...streamOptions,
autoClose: false,
_schemaFormat: "streaming_events"
});
const rootEventFilter = new require_utils$1._RootEventFilter({ ...streamOptions });
const logStream = this._streamLog(input, logStreamCallbackHandler, config);
for await (const log of logStream) {
if (!runLog) runLog = require_tracers_log_stream.RunLog.fromRunLogPatch(log);
else runLog = runLog.concat(log);
if (runLog.state === void 0) throw new Error(`Internal error: "streamEvents" state is missing. Please open a bug report.`);
if (!hasEncounteredStartEvent) {
hasEncounteredStartEvent = true;
const state = { ...runLog.state };
const event = {
run_id: state.id,
event: `on_${state.type}_start`,
name: rootName,
tags: rootTags,
metadata: rootMetadata,
data: { input }
};
if (rootEventFilter.includeEvent(event, state.type)) yield event;
}
const paths = log.ops.filter((op) => op.path.startsWith("/logs/")).map((op) => op.path.split("/")[2]);
const dedupedPaths = [...new Set(paths)];
for (const path of dedupedPaths) {
let eventType;
let data = {};
const logEntry = runLog.state.logs[path];
if (logEntry.end_time === void 0) if (logEntry.streamed_output.length > 0) eventType = "stream";
else eventType = "start";
else eventType = "end";
if (eventType === "start") {
if (logEntry.inputs !== void 0) data.input = logEntry.inputs;
} else if (eventType === "end") {
if (logEntry.inputs !== void 0) data.input = logEntry.inputs;
data.output = logEntry.final_output;
} else if (eventType === "stream") {
const chunkCount = logEntry.streamed_output.length;
if (chunkCount !== 1) throw new Error(`Expected exactly one chunk of streamed output, got ${chunkCount} instead. Encountered in: "${logEntry.name}"`);
data = { chunk: logEntry.streamed_output[0] };
logEntry.streamed_output = [];
}
yield {
event: `on_${logEntry.type}_${eventType}`,
name: logEntry.name,
run_id: logEntry.id,
tags: logEntry.tags,
metadata: logEntry.metadata,
data
};
}
const { state } = runLog;
if (state.streamed_output.length > 0) {
const chunkCount = state.streamed_output.length;
if (chunkCount !== 1) throw new Error(`Expected exactly one chunk of streamed output, got ${chunkCount} instead. Encountered in: "${state.name}"`);
const data = { chunk: state.streamed_output[0] };
state.streamed_output = [];
const event = {
event: `on_${state.type}_stream`,
run_id: state.id,
tags: rootTags,
metadata: rootMetadata,
name: rootName,
data
};
if (rootEventFilter.includeEvent(event, state.type)) yield event;
}
}
const state = runLog?.state;
if (state !== void 0) {
const event = {
event: `on_${state.type}_end`,
name: rootName,
run_id: state.id,
tags: rootTags,
metadata: rootMetadata,
data: { output: state.final_output }
};
if (rootEventFilter.includeEvent(event, state.type)) yield event;
}
}
static isRunnable(thing) {
return require_utils$1.isRunnableInterface(thing);
}
/**
* Bind lifecycle listeners to a Runnable, returning a new Runnable.
* The Run object contains information about the run, including its id,
* type, input, output, error, startTime, endTime, and any tags or metadata
* added to the run.
*
* @param {Object} params - The object containing the callback functions.
* @param {(run: Run) => void} params.onStart - Called before the runnable starts running, with the Run object.
* @param {(run: Run) => void} params.onEnd - Called after the runnable finishes running, with the Run object.
* @param {(run: Run) => void} params.onError - Called if the runnable throws an error, with the Run object.
*/
withListeners({ onStart, onEnd, onError }) {
return new RunnableBinding({
bound: this,
config: {},
configFactories: [(config) => ({ callbacks: [new require_root_listener.RootListenersTracer({
config,
onStart,
onEnd,
onError
})] })]
});
}
/**
* Convert a runnable to a tool. Return a new instance of `RunnableToolLike`
* which contains the runnable, name, description and schema.
*
* @template {T extends RunInput = RunInput} RunInput - The input type of the runnable. Should be the same as the `RunInput` type of the runnable.
*
* @param fields
* @param {string | undefined} [fields.name] The name of the tool. If not provided, it will default to the name of the runnable.
* @param {string | undefined} [fields.description] The description of the tool. Falls back to the description on the Zod schema if not provided, or undefined if neither are provided.
* @param {z.ZodType<T>} [fields.schema] The Zod schema for the input of the tool. Infers the Zod type from the input type of the runnable.
* @returns {RunnableToolLike<z.ZodType<T>, RunOutput>} An instance of `RunnableToolLike` which is a runnable that can be used as a tool.
*/
asTool(fields) {
return convertRunnableToTool(this, fields);
}
};
/**
* Wraps a runnable and applies partial config upon invocation.
*
* @example
* ```typescript
* import {
* type RunnableConfig,
* RunnableLambda,
* } from "@langchain/core/runnables";
*
* const enhanceProfile = (
* profile: Record<string, any>,
* config?: RunnableConfig
* ) => {
* if (config?.configurable?.role) {
* return { ...profile, role: config.configurable.role };
* }
* return profile;
* };
*
* const runnable = RunnableLambda.from(enhanceProfile);
*
* // Bind configuration to the runnable to set the user's role dynamically
* const adminRunnable = runnable.withConfig({ configurable: { role: "Admin" } });
* const userRunnable = runnable.withConfig({ configurable: { role: "User" } });
*
* const result1 = await adminRunnable.invoke({
* name: "Alice",
* email: "alice@example.com"
* });
*
* // { name: "Alice", email: "alice@example.com", role: "Admin" }
*
* const result2 = await userRunnable.invoke({
* name: "Bob",
* email: "bob@example.com"
* });
*
* // { name: "Bob", email: "bob@example.com", role: "User" }
* ```
*/
var RunnableBinding = class RunnableBinding extends Runnable {
static lc_name() {
return "RunnableBinding";
}
lc_namespace = ["langchain_core", "runnables"];
lc_serializable = true;
bound;
config;
kwargs;
configFactories;
constructor(fields) {
super(fields);
this.bound = fields.bound;
this.kwargs = fields.kwargs;
this.config = fields.config;
this.configFactories = fields.configFactories;
}
getName(suffix) {
return this.bound.getName(suffix);
}
async _mergeConfig(...options) {
const config = require_config.mergeConfigs(this.config, ...options);
return require_config.mergeConfigs(config, ...this.configFactories ? await Promise.all(this.configFactories.map(async (configFactory) => await configFactory(config))) : []);
}
withConfig(config) {
return new this.constructor({
bound: this.bound,
kwargs: this.kwargs,
config: {
...this.config,
...config
}
});
}
withRetry(fields) {
return new RunnableRetry({
bound: this.bound,
kwargs: this.kwargs,
config: this.config,
maxAttemptNumber: fields?.stopAfterAttempt,
...fields
});
}
async invoke(input, options) {
return this.bound.invoke(input, await this._mergeConfig(options, this.kwargs));
}
async batch(inputs, options, batchOptions) {
const mergedOptions = Array.isArray(options) ? await Promise.all(options.map(async (individualOption) => this._mergeConfig(require_config.ensureConfig(individualOption), this.kwargs))) : await this._mergeConfig(require_config.ensureConfig(options), this.kwargs);
return this.bound.batch(inputs, mergedOptions, batchOptions);
}
/** @internal */
_concatOutputChunks(first, second) {
return this.bound._concatOutputChunks(first, second);
}
async *_streamIterator(input, options) {
yield* this.bound._streamIterator(input, await this._mergeConfig(require_config.ensureConfig(options), this.kwargs));
}
async stream(input, options) {
return this.bound.stream(input, await this._mergeConfig(require_config.ensureConfig(options), this.kwargs));
}
async *transform(generator, options) {
yield* this.bound.transform(generator, await this._mergeConfig(require_config.ensureConfig(options), this.kwargs));
}
streamEvents(input, options, streamOptions) {
const outerThis = this;
const generator = async function* () {
yield* outerThis.bound.streamEvents(input, {
...await outerThis._mergeConfig(require_config.ensureConfig(options), outerThis.kwargs),
version: options.version
}, streamOptions);
};
return require_utils_stream.IterableReadableStream.fromAsyncGenerator(generator());
}
static isRunnableBinding(thing) {
return thing.bound && Runnable.isRunnable(thing.bound);
}
/**
* Bind lifecycle listeners to a Runnable, returning a new Runnable.
* The Run object contains information about the run, including its id,
* type, input, output, error, startTime, endTime, and any tags or metadata
* added to the run.
*
* @param {Object} params - The object containing the callback functions.
* @param {(run: Run) => void} params.onStart - Called before the runnable starts running, with the Run object.
* @param {(run: Run) => void} params.onEnd - Called after the runnable finishes running, with the Run object.
* @param {(run: Run) => void} params.onError - Called if the runnable throws an error, with the Run object.
*/
withListeners({ onStart, onEnd, onError }) {
return new RunnableBinding({
bound: this.bound,
kwargs: this.kwargs,
config: this.config,
configFactories: [(config) => ({ callbacks: [new require_root_listener.RootListenersTracer({
config,
onStart,
onEnd,
onError
})] })]
});
}
};
/**
* A runnable that delegates calls to another runnable
* with each element of the input sequence.
* @example
* ```typescript
* import { RunnableEach, RunnableLambda } from "@langchain/core/runnables";
*
* const toUpperCase = (input: string): string => input.toUpperCase();
* const addGreeting = (input: string): string => `Hello, ${input}!`;
*
* const upperCaseLambda = RunnableLambda.from(toUpperCase);
* const greetingLambda = RunnableLambda.from(addGreeting);
*
* const chain = new RunnableEach({
* bound: upperCaseLambda.pipe(greetingLambda),
* });
*
* const result = await chain.invoke(["alice", "bob", "carol"])
*
* // ["Hello, ALICE!", "Hello, BOB!", "Hello, CAROL!"]
* ```
*/
var RunnableEach = class RunnableEach extends Runnable {
static lc_name() {
return "RunnableEach";
}
lc_serializable = true;
lc_namespace = ["langchain_core", "runnables"];
bound;
constructor(fields) {
super(fields);
this.bound = fields.bound;
}
/**
* Invokes the runnable with the specified input and configuration.
* @param input The input to invoke the runnable with.
* @param config The configuration to invoke the runnable with.
* @returns A promise that resolves to the output of the runnable.
*/
async invoke(inputs, config) {
return this._callWithConfig(this._invoke.bind(this), inputs, config);
}
/**
* A helper method that is used to invoke the runnable with the specified input and configuration.
* @param input The input to invoke the runnable with.
* @param config The configuration to invoke the runnable with.
* @returns A promise that resolves to the output of the runnable.
*/
async _invoke(inputs, config, runManager) {
return this.bound.batch(inputs, require_config.patchConfig(config, { callbacks: runManager?.getChild() }));
}
/**
* Bind lifecycle listeners to a Runnable, returning a new Runnable.
* The Run object contains information about the run, including its id,
* type, input, output, error, startTime, endTime, and any tags or metadata
* added to the run.
*
* @param {Object} params - The object containing the callback functions.
* @param {(run: Run) => void} params.onStart - Called before the runnable starts running, with the Run object.
* @param {(run: Run) => void} params.onEnd - Called after the runnable finishes running, with the Run object.
* @param {(run: Run) => void} params.onError - Called if the runnable throws an error, with the Run object.
*/
withListeners({ onStart, onEnd, onError }) {
return new RunnableEach({ bound: this.bound.withListeners({
onStart,
onEnd,
onError
}) });
}
};
/**
* Base class for runnables that can be retried a
* specified number of times.
* @example
* ```typescript
* import {
* RunnableLambda,
* RunnableRetry,
* } from "@langchain/core/runnables";
*
* // Simulate an API call that fails
* const simulateApiCall = (input: string): string => {
* console.log(`Attempting API call with input: ${input}`);
* throw new Error("API call failed due to network issue");
* };
*
* const apiCallLambda = RunnableLambda.from(simulateApiCall);
*
* // Apply retry logic using the .withRetry() method
* const apiCallWithRetry = apiCallLambda.withRetry({ stopAfterAttempt: 3 });
*
* // Alternatively, create a RunnableRetry instance manually
* const manualRetry = new RunnableRetry({
* bound: apiCallLambda,
* maxAttemptNumber: 3,
* config: {},
* });
*
* // Example invocation using the .withRetry() method
* const res = await apiCallWithRetry
* .invoke("Request 1")
* .catch((error) => {
* console.error("Failed after multiple retries:", error.message);
* });
*
* // Example invocation using the manual retry instance
* const res2 = await manualRetry
* .invoke("Request 2")
* .catch((error) => {
* console.error("Failed after multiple retries:", error.message);
* });
* ```
*/
var RunnableRetry = class extends RunnableBinding {
static lc_name() {
return "RunnableRetry";
}
lc_namespace = ["langchain_core", "runnables"];
maxAttemptNumber = 3;
onFailedAttempt = () => {};
constructor(fields) {
super(fields);
this.maxAttemptNumber = fields.maxAttemptNumber ?? this.maxAttemptNumber;
this.onFailedAttempt = fields.onFailedAttempt ?? this.onFailedAttempt;
}
_patchConfigForRetry(attempt, config, runManager) {
const tag = attempt > 1 ? `retry:attempt:${attempt}` : void 0;
return require_config.patchConfig(config, { callbacks: runManager?.getChild(tag) });
}
async _invoke(input, config, runManager) {
return require_index$1.default((attemptNumber) => super.invoke(input, this._patchConfigForRetry(attemptNumber, config, runManager)), {
onFailedAttempt: ({ error }) => this.onFailedAttempt(error, input),
retries: Math.max(this.maxAttemptNumber - 1, 0),
randomize: true
});
}
/**
* Method that invokes the runnable with the specified input, run manager,
* and config. It handles the retry logic by catching any errors and
* recursively invoking itself with the updated config for the next retry
* attempt.
* @param input The input for the runnable.
* @param runManager The run manager for the runnable.
* @param config The config for the runnable.
* @returns A promise that resolves to the output of the runnable.
*/
async invoke(input, config) {
return this._callWithConfig(this._invoke.bind(this), input, config);
}
async _batch(inputs, configs, runManagers, batchOptions) {
const resultsMap = {};
try {
await require_index$1.default(async (attemptNumber) => {
const remainingIndexes = inputs.map((_, i) => i).filter((i) => resultsMap[i.toString()] === void 0 || resultsMap[i.toString()] instanceof Error);
const remainingInputs = remainingIndexes.map((i) => inputs[i]);
const patchedConfigs = remainingIndexes.map((i) => this._patchConfigForRetry(attemptNumber, configs?.[i], runManagers?.[i]));
const results = await super.batch(remainingInputs, patchedConfigs, {
...batchOptions,
returnExceptions: true
});
let firstException;
for (let i = 0; i < results.length; i += 1) {
const result = results[i];
const resultMapIndex = remainingIndexes[i];
if (result instanceof Error) {
if (firstException === void 0) {
firstException = result;
firstException.input = remainingInputs[i];
}
}
resultsMap[resultMapIndex.toString()] = result;
}
if (firstException) throw firstException;
return results;
}, {
onFailedAttempt: ({ error }) => this.onFailedAttempt(error, error.input),
retries: Math.max(this.maxAttemptNumber - 1, 0),
randomize: true
});
} catch (e) {
if (batchOptions?.returnExceptions !== true) throw e;
}
return Object.keys(resultsMap).sort((a, b) => parseInt(a, 10) - parseInt(b, 10)).map((key) => resultsMap[parseInt(key, 10)]);
}
async batch(inputs, options, batchOptions) {
return this._batchWithConfig(this._batch.bind(this), inputs, options, batchOptions);
}
};
/**
* A sequence of runnables, where the output of each is the input of the next.
* @example
* ```typescript
* const promptTemplate = PromptTemplate.fromTemplate(
* "Tell me a joke about {topic}",
* );
* const chain = RunnableSequence.from([promptTemplate, new ChatOpenAI({ model: "gpt-4o-mini" })]);
* const result = await chain.invoke({ topic: "bears" });
* ```
*/
var RunnableSequence = class RunnableSequence extends Runnable {
static lc_name() {
return "RunnableSequence";
}
first;
middle = [];
last;
omitSequenceTags = false;
lc_serializable = true;
lc_namespace = ["langchain_core", "runnables"];
constructor(fields) {
super(fields);
this.first = fields.first;
this.middle = fields.middle ?? this.middle;
this.last = fields.last;
this.name = fields.name;
this.omitSequenceTags = fields.omitSequenceTags ?? this.omitSequenceTags;
}
get steps() {
return [
this.first,
...this.middle,
this.last
];
}
async invoke(input, options) {
const config = require_config.ensureConfig(options);
const runManager = await (await require_config.getCallbackManagerForConfig(config))?.handleChainStart(this.toJSON(), _coerceToDict(input, "input"), config.runId, void 0, void 0, void 0, config?.runName);
delete config.runId;
let nextStepInput = input;
let finalOutput;
try {
const initialSteps = [this.first, ...this.middle];
for (let i = 0; i < initialSteps.length; i += 1) nextStepInput = await require_signal.raceWithSignal(initialSteps[i].invoke(nextStepInput, require_config.patchConfig(config, { callbacks: runManager?.getChild(this.omitSequenceTags ? void 0 : `seq:step:${i + 1}`) })), config.signal);
if (config.signal?.aborted) throw require_signal.getAbortSignalError(config.signal);
finalOutput = await this.last.invoke(nextStepInput, require_config.patchConfig(config, { callbacks: runManager?.getChild(this.omitSequenceTags ? void 0 : `seq:step:${this.steps.length}`) }));
} catch (e) {
await runManager?.handleChainError(e);
throw e;
}
await runManager?.handleChainEnd(_coerceToDict(finalOutput, "output"));
return finalOutput;
}
async batch(inputs, options, batchOptions) {
const configList = this._getOptionsList(options ?? {}, inputs.length);
const callbackManagers = await Promise.all(configList.map(require_config.getCallbackManagerForConfig));
const runManagers = await Promise.all(callbackManagers.map(async (callbackManager, i) => {
const handleStartRes = await callbackManager?.handleChainStart(this.toJSON(), _coerceToDict(inputs[i], "input"), configList[i].runId, void 0, void 0, void 0, configList[i].runName);
delete configList[i].runId;
return handleStartRes;
}));
let nextStepInputs = inputs;
try {
for (let i = 0; i < this.steps.length; i += 1) nextStepInputs = await require_signal.raceWithSignal(this.steps[i].batch(nextStepInputs, runManagers.map((runManager, j) => {
const childRunManager = runManager?.getChild(this.omitSequenceTags ? void 0 : `seq:step:${i + 1}`);
return require_config.patchConfig(configList[j], { callbacks: childRunManager });
}), batchOptions), configList[0]?.signal);
} catch (e) {
await Promise.all(runManagers.map((runManager) => runManager?.handleChainError(e)));
throw e;
}
await Promise.all(runManagers.map((runManager) => runManager?.handleChainEnd(_coerceToDict(nextStepInputs, "output"))));
return nextStepInputs;
}
/** @internal */
_concatOutputChunks(first, second) {
return this.last._concatOutputChunks(first, second);
}
async *_streamIterator(input, options) {
const callbackManager_ = await require_config.getCallbackManagerForConfig(options);
const { runId, ...otherOptions } = options ?? {};
const runManager = await callbackManager_?.handleChainStart(this.toJSON(), _coerceToDict(input, "input"), runId, void 0, void 0, void 0, otherOptions?.runName);
const steps = [
this.first,
...this.middle,
this.last
];
let concatSupported = true;
let finalOutput;
async function* inputGenerator() {
yield input;
}
try {
let finalGenerator = steps[0].transform(inputGenerator(), require_config.patchConfig(otherOptions, { callbacks: runManager?.getChild(this.omitSequenceTags ? void 0 : `seq:step:1`) }));
for (let i = 1; i < steps.length; i += 1) finalGenerator = await steps[i].transform(finalGenerator, require_config.patchConfig(otherOptions, { callbacks: runManager?.getChild(this.omitSequenceTags ? void 0 : `seq:step:${i + 1}`) }));
for await (const chunk of finalGenerator) {
options?.signal?.throwIfAborted();
yield chunk;
if (concatSupported) if (finalOutput === void 0) finalOutput = chunk;
else try {
finalOutput = this._concatOutputChunks(finalOutput, chunk);
} catch {
finalOutput = void 0;
concatSupported = false;
}
}
} catch (e) {
await runManager?.handleChainError(e);
throw e;
}
await runManager?.handleChainEnd(_coerceToDict(finalOutput, "output"));
}
getGraph(config) {
const graph = new require_runnables_graph.Graph();
let currentLastNode = null;
this.steps.forEach((step, index) => {
const stepGraph = step.getGraph(config);
if (index !== 0) stepGraph.trimFirstNode();
if (index !== this.steps.length - 1) stepGraph.trimLastNode();
graph.extend(stepGraph);
const stepFirstNode = stepGraph.firstNode();
if (!stepFirstNode) throw new Error(`Runnable ${step} has no first node`);
if (currentLastNode) graph.addEdge(currentLastNode, stepFirstNode);
currentLastNode = stepGraph.lastNode();
});
return graph;
}
pipe(coerceable) {
if (RunnableSequence.isRunnableSequence(coerceable)) return new RunnableSequence({
first: this.first,
middle: this.middle.concat([
this.last,
coerceable.first,
...coerceable.middle
]),
last: coerceable.last,
name: this.name ?? coerceable.name
});
else return new RunnableSequence({
first: this.first,
middle: [...this.middle, this.last],
last: _coerceToRunnable(coerceable),
name: this.name
});
}
static isRunnableSequence(thing) {
return Array.isArray(thing.middle) && Runnable.isRunnable(thing);
}
static from([first, ...runnables], nameOrFields) {
let extra = {};
if (typeof nameOrFields === "string") extra.name = nameOrFields;
else if (nameOrFields !== void 0) extra = nameOrFields;
return new RunnableSequence({
...extra,
first: _coerceToRunnable(first),
middle: runnables.slice(0, -1).map(_coerceToRunnable),
last: _coerceToRunnable(runnables[runnables.length - 1])
});
}
};
/**
* A runnable that runs a mapping of runnables in parallel,
* and returns a mapping of their outputs.
* @example
* ```typescript
* const mapChain = RunnableMap.from({
* joke: PromptTemplate.fromTemplate("Tell me a joke about {topic}").pipe(
* new ChatAnthropic({}),
* ),
* poem: PromptTemplate.fromTemplate("write a 2-line poem about {topic}").pipe(
* new ChatAnthropic({}),
* ),
* });
* const result = await mapChain.invoke({ topic: "bear" });
* ```
*/
var RunnableMap = class RunnableMap extends Runnable {
static lc_name() {
return "RunnableMap";
}
lc_namespace = ["langchain_core", "runnables"];
lc_serializable = true;
steps;
getStepsKeys() {
return Object.keys(this.steps);
}
constructor(fields) {
super(fields);
this.steps = {};
for (const [key, value] of Object.entries(fields.steps)) this.steps[key] = _coerceToRunnable(value);
}
static from(steps) {
return new RunnableMap({ steps });
}
async invoke(input, options) {
const config = require_config.ensureConfig(options);
const runManager = await (await require_config.getCallbackManagerForConfig(config))?.handleChainStart(this.toJSON(), { input }, config.runId, void 0, void 0, void 0, config?.runName);
delete config.runId;
const output = {};
try {
const promises = Object.entries(this.steps).map(async ([key, runnable]) => {
output[key] = await runnable.invoke(input, require_config.patchConfig(config, { callbacks: runManager?.getChild(`map:key:${key}`) }));
});
await require_signal.raceWithSignal(Promise.all(promises), config.signal);
} catch (e) {
await runManager?.handleChainError(e);
throw e;
}
await runManager?.handleChainEnd(output);
return output;
}
async *_transform(generator, runManager, options) {
const steps = { ...this.steps };
const inputCopies = require_utils_stream.atee(generator, Object.keys(steps).length);
const tasks = new Map(Object.entries(steps).map(([key, runnable], i) => {
const gen = runnable.transform(inputCopies[i], require_config.patchConfig(options, { callbacks: runManager?.getChild(`map:key:${key}`) }));
return [key, gen.next().then((result) => ({
key,
gen,
result
}))];
}));
while (tasks.size) {
const { key, result, gen } = await require_signal.raceWithSignal(Promise.race(tasks.values()), options?.signal);
tasks.delete(key);
if (!result.done) {
yield { [key]: result.value };
tasks.set(key, gen.next().then((result) => ({
key,
gen,
result
})));
}
}
}
transform(generator, options) {
return this._transformStreamWithConfig(generator, this._transform.bind(this), options);
}
async stream(input, options) {
async function* generator() {
yield input;
}
const config = require_config.ensureConfig(options);
const wrappedGenerator = new require_utils_stream.AsyncGeneratorWithSetup({
generator: this.transform(generator(), config),
config
});
await wrappedGenerator.setup;
return require_utils_stream.IterableReadableStream.fromAsyncGenerator(wrappedGenerator);
}
};
/**
* A runnable that wraps a traced LangSmith function.
*/
var RunnableTraceable = class RunnableTraceable extends Runnable {
lc_serializable = false;
lc_namespace = ["langchain_core", "runnables"];
func;
constructor(fields) {
super(fields);
if (!(0, langsmith_singletons_traceable.isTraceableFunction)(fields.func)) throw new Error("RunnableTraceable requires a function that is wrapped in traceable higher-order function");
this.func = fields.func;
}
async invoke(input, options) {
const [config] = this._getOptionsList(options ?? {}, 1);
const callbacks = await require_config.getCallbackManagerForConfig(config);
return require_signal.raceWithSignal(this.func(require_config.patchConfig(config, { callbacks }), input), config?.signal);
}
async *_streamIterator(input, options) {
const [config] = this._getOptionsList(options ?? {}, 1);
const result = await this.invoke(input, options);
if (require_iter.isAsyncIterable(result)) {
for await (const item of result) {
config?.signal?.throwIfAborted();
yield item;
}
return;
}
if (require_iter.isIterator(result)) {
while (true) {
config?.signal?.throwIfAborted();
const state = result.next();
if (state.done) break;
yield state.value;
}
return;
}
yield result;
}
static from(func) {
return new RunnableTraceable({ func });
}
};
function assertNonTraceableFunction(func) {
if ((0, langsmith_singletons_traceable.isTraceableFunction)(func)) throw new Error("RunnableLambda requires a function that is not wrapped in traceable higher-order function. This shouldn't happen.");
}
/**
* A runnable that wraps an arbitrary function that takes a single argument.
* @example
* ```typescript
* import { RunnableLambda } from "@langchain/core/runnables";
*
* const add = (input: { x: number; y: number }) => input.x + input.y;
*
* const multiply = (input: { value: number; multiplier: number }) =>
* input.value * input.multiplier;
*
* // Create runnables for the functions
* const addLambda = RunnableLambda.from(add);
* const multiplyLambda = RunnableLambda.from(multiply);
*
* // Chain the lambdas for a mathematical operation
* const chainedLambda = addLambda.pipe((result) =>
* multiplyLambda.invoke({ value: result, multiplier: 2 })
* );
*
* // Example invocation of the chainedLambda
* const result = await chainedLambda.invoke({ x: 2, y: 3 });
*
* // Will log "10" (since (2 + 3) * 2 = 10)
* ```
*/
var RunnableLambda = class RunnableLambda extends Runnable {
static lc_name() {
return "RunnableLambda";
}
lc_namespace = ["langchain_core", "runnables"];
func;
constructor(fields) {
if ((0, langsmith_singletons_traceable.isTraceableFunction)(fields.func)) return RunnableTraceable.from(fields.func);
super(fields);
assertNonTraceableFunction(fields.func);
this.func = fields.func;
}
static from(func) {
return new RunnableLambda({ func });
}
async _invoke(input, config, runManager) {
return new Promise((resolve, reject) => {
const childConfig = require_config.patchConfig(config, {
callbacks: runManager?.getChild(),
recursionLimit: (config?.recursionLimit ?? 25) - 1
});
require_index.AsyncLocalStorageProviderSingleton.runWithConfig(require_config.pickRunnableConfigKeys(childConfig), async () => {
try {
let output = await this.func(input, { ...childConfig });
if (output && Runnable.isRunnable(output)) {
if (config?.recursionLimit === 0) throw new Error("Recursion limit reached.");
output = await output.invoke(input, {
...childConfig,
recursionLimit: (childConfig.recursionLimit ?? 25) - 1
});
} else if (require_iter.isAsyncIterable(output)) {
let finalOutput;
for await (const chunk of require_iter.consumeAsyncIterableInContext(childConfig, output)) {
config?.signal?.throwIfAborted();
if (finalOutput === void 0) finalOutput = chunk;
else try {
finalOutput = this._concatOutputChunks(finalOutput, chunk);
} catch {
finalOutput = chunk;
}
}
output = finalOutput;
} else if (require_iter.isIterableIterator(output)) {
let finalOutput;
for (const chunk of require_iter.consumeIteratorInContext(childConfig, output)) {
config?.signal?.throwIfAborted();
if (finalOutput === void 0) finalOutput = chunk;
else try {
finalOutput = this._concatOutputChunks(finalOutput, chunk);
} catch {
finalOutput = chunk;
}
}
output = finalOutput;
}
resolve(output);
} catch (e) {
reject(e);
}
});
});
}
async invoke(input, options) {
return this._callWithConfig(this._invoke.bind(this), input, options);
}
async *_transform(generator, runManager, config) {
let finalChunk;
for await (const chunk of generator) if (finalChunk === void 0) finalChunk = chunk;
else try {
finalChunk = this._concatOutputChunks(finalChunk, chunk);
} catch {
finalChunk = chunk;
}
const childConfig = require_config.patchConfig(config, {
callbacks: runManager?.getChild(),
recursionLimit: (config?.recursionLimit ?? 25) - 1
});
const output = await new Promise((resolve, reject) => {
require_index.AsyncLocalStorageProviderSingleton.runWithConfig(require_config.pickRunnableConfigKeys(childConfig), async () => {
try {
resolve(await this.func(finalChunk, {
...childConfig,
config: childConfig
}));
} catch (e) {
reject(e);
}
});
});
if (output && Runnable.isRunnable(output)) {
if (config?.recursionLimit === 0) throw new Error("Recursion limit reached.");
const stream = await output.stream(finalChunk, childConfig);
for await (const chunk of stream) yield chunk;
} else if (require_iter.isAsyncIterable(output)) for await (const chunk of require_iter.consumeAsyncIterableInContext(childConfig, output)) {
config?.signal?.throwIfAborted();
yield chunk;
}
else if (require_iter.isIterableIterator(output)) for (const chunk of require_iter.consumeIteratorInContext(childConfig, output)) {
config?.signal?.throwIfAborted();
yield chunk;
}
else yield output;
}
transform(generator, options) {
return this._transformStreamWithConfig(generator, this._transform.bind(this), options);
}
async stream(input, options) {
async function* generator() {
yield input;
}
const config = require_config.ensureConfig(options);
const wrappedGenerator = new require_utils_stream.AsyncGeneratorWithSetup({
generator: this.transform(generator(), config),
config
});
await wrappedGenerator.setup;
return require_utils_stream.IterableReadableStream.fromAsyncGenerator(wrappedGenerator);
}
};
/**
* A runnable that runs a mapping of runnables in parallel,
* and returns a mapping of their outputs.
* @example
* ```typescript
* import {
* RunnableLambda,
* RunnableParallel,
* } from "@langchain/core/runnables";
*
* const addYears = (age: number): number => age + 5;
* const yearsToFifty = (age: number): number => 50 - age;
* const yearsToHundred = (age: number): number => 100 - age;
*
* const addYearsLambda = RunnableLambda.from(addYears);
* const milestoneFiftyLambda = RunnableLambda.from(yearsToFifty);
* const milestoneHundredLambda = RunnableLambda.from(yearsToHundred);
*
* // Pipe will coerce objects into RunnableParallel by default, but we
* // explicitly instantiate one here to demonstrate
* const sequence = addYearsLambda.pipe(
* RunnableParallel.from({
* years_to_fifty: milestoneFiftyLambda,
* years_to_hundred: milestoneHundredLambda,
* })
* );
*
* // Invoke the sequence with a single age input
* const res = await sequence.invoke(25);
*
* // { years_to_fifty: 20, years_to_hundred: 70 }
* ```
*/
var RunnableParallel = class extends RunnableMap {};
/**
* A Runnable that can fallback to other Runnables if it fails.
* External APIs (e.g., APIs for a language model) may at times experience
* degraded performance or even downtime.
*
* In these cases, it can be useful to have a fallback Runnable that can be
* used in place of the original Runnable (e.g., fallback to another LLM provider).
*
* Fallbacks can be defined at the level of a single Runnable, or at the level
* of a chain of Runnables. Fallbacks are tried in order until one succeeds or
* all fail.
*
* While you can instantiate a `RunnableWithFallbacks` directly, it is usually
* more convenient to use the `withFallbacks` method on an existing Runnable.
*
* When streaming, fallbacks will only be called on failures during the initial
* stream creation. Errors that occur after a stream starts will not fallback
* to the next Runnable.
*
* @example
* ```typescript
* import {
* RunnableLambda,
* RunnableWithFallbacks,
* } from "@langchain/core/runnables";
*
* const primaryOperation = (input: string): string => {
* if (input !== "safe") {
* throw new Error("Primary operation failed due to unsafe input");
* }
* return `Processed: ${input}`;
* };
*
* // Define a fallback operation that processes the input differently
* const fallbackOperation = (input: string): string =>
* `Fallback processed: ${input}`;
*
* const primaryRunnable = RunnableLambda.from(primaryOperation);
* const fallbackRunnable = RunnableLambda.from(fallbackOperation);
*
* // Apply the fallback logic using the .withFallbacks() method
* const runnableWithFallback = primaryRunnable.withFallbacks([fallbackRunnable]);
*
* // Alternatively, create a RunnableWithFallbacks instance manually
* const manualFallbackChain = new RunnableWithFallbacks({
* runnable: primaryRunnable,
* fallbacks: [fallbackRunnable],
* });
*
* // Example invocation using .withFallbacks()
* const res = await runnableWithFallback
* .invoke("unsafe input")
* .catch((error) => {
* console.error("Failed after all attempts:", error.message);
* });
*
* // "Fallback processed: unsafe input"
*
* // Example invocation using manual instantiation
* const res = await manualFallbackChain
* .invoke("safe")
* .catch((error) => {
* console.error("Failed after all attempts:", error.message);
* });
*
* // "Processed: safe"
* ```
*/
var RunnableWithFallbacks = class extends Runnable {
static lc_name() {
return "RunnableWithFallbacks";
}
lc_namespace = ["langchain_core", "runnables"];
lc_serializable = true;
runnable;
fallbacks;
constructor(fields) {
super(fields);
this.runnable = fields.runnable;
this.fallbacks = fields.fallbacks;
}
*runnables() {
yield this.runnable;
for (const fallback of this.fallbacks) yield fallback;
}
async invoke(input, options) {
const config = require_config.ensureConfig(options);
const callbackManager_ = await require_config.getCallbackManagerForConfig(config);
const { runId, ...otherConfigFields } = config;
const runManager = await callbackManager_?.handleChainStart(this.toJSON(), _coerceToDict(input, "input"), runId, void 0, void 0, void 0, otherConfigFields?.runName);
const childConfig = require_config.patchConfig(otherConfigFields, { callbacks: runManager?.getChild() });
return await require_index.AsyncLocalStorageProviderSingleton.runWithConfig(childConfig, async () => {
let firstError;
for (const runnable of this.runnables()) {
config?.signal?.throwIfAborted();
try {
const output = await runnable.invoke(input, childConfig);
await runManager?.handleChainEnd(_coerceToDict(output, "output"));
return output;
} catch (e) {
if (firstError === void 0) firstError = e;
}
}
if (firstError === void 0) throw new Error("No error stored at end of fallback.");
await runManager?.handleChainError(firstError);
throw firstError;
});
}
async *_streamIterator(input, options) {
const config = require_config.ensureConfig(options);
const callbackManager_ = await require_config.getCallbackManagerForConfig(config);
const { runId, ...otherConfigFields } = config;
const runManager = await callbackManager_?.handleChainStart(this.toJSON(), _coerceToDict(input, "input"), runId, void 0, void 0, void 0, otherConfigFields?.runName);
let firstError;
let stream;
for (const runnable of this.runnables()) {
config?.signal?.throwIfAborted();
const childConfig = require_config.patchConfig(otherConfigFields, { callbacks: runManager?.getChild() });
try {
stream = require_iter.consumeAsyncIterableInContext(childConfig, await runnable.stream(input, childConfig));
break;
} catch (e) {
if (firstError === void 0) firstError = e;
}
}
if (stream === void 0) {
const error = firstError ?? /* @__PURE__ */ new Error("No error stored at end of fallback.");
await runManager?.handleChainError(error);
throw error;
}
let output;
try {
for await (const chunk of stream) {
yield chunk;
try {
output = output === void 0 ? output : this._concatOutputChunks(output, chunk);
} catch {
output = void 0;
}
}
} catch (e) {
await runManager?.handleChainError(e);
throw e;
}
await runManager?.handleChainEnd(_coerceToDict(output, "output"));
}
async batch(inputs, options, batchOptions) {
if (batchOptions?.returnExceptions) throw new Error("Not implemented.");
const configList = this._getOptionsList(options ?? {}, inputs.length);
const callbackManagers = await Promise.all(configList.map((config) => require_config.getCallbackManagerForConfig(config)));
const runManagers = await Promise.all(callbackManagers.map(async (callbackManager, i) => {
const handleStartRes = await callbackManager?.handleChainStart(this.toJSON(), _coerceToDict(inputs[i], "input"), configList[i].runId, void 0, void 0, void 0, configList[i].runName);
delete configList[i].runId;
return handleStartRes;
}));
let firstError;
for (const runnable of this.runnables()) {
configList[0].signal?.throwIfAborted();
try {
const outputs = await runnable.batch(inputs, runManagers.map((runManager, j) => require_config.patchConfig(configList[j], { callbacks: runManager?.getChild() })), batchOptions);
await Promise.all(runManagers.map((runManager, i) => runManager?.handleChainEnd(_coerceToDict(outputs[i], "output"))));
return outputs;
} catch (e) {
if (firstError === void 0) firstError = e;
}
}
if (!firstError) throw new Error("No error stored at end of fallbacks.");
await Promise.all(runManagers.map((runManager) => runManager?.handleChainError(firstError)));
throw firstError;
}
};
function _coerceToRunnable(coerceable) {
if (typeof coerceable === "function") return new RunnableLambda({ func: coerceable });
else if (Runnable.isRunnable(coerceable)) return coerceable;
else if (!Array.isArray(coerceable) && typeof coerceable === "object") {
const runnables = {};
for (const [key, value] of Object.entries(coerceable)) runnables[key] = _coerceToRunnable(value);
return new RunnableMap({ steps: runnables });
} else throw new Error(`Expected a Runnable, function or object.\nInstead got an unsupported type.`);
}
/**
* A runnable that assigns key-value pairs to inputs of type `Record<string, unknown>`.
* @example
* ```typescript
* import {
* RunnableAssign,
* RunnableLambda,
* RunnableParallel,
* } from "@langchain/core/runnables";
*
* const calculateAge = (x: { birthYear: number }): { age: number } => {
* const currentYear = new Date().getFullYear();
* return { age: currentYear - x.birthYear };
* };
*
* const createGreeting = (x: { name: string }): { greeting: string } => {
* return { greeting: `Hello, ${x.name}!` };
* };
*
* const mapper = RunnableParallel.from({
* age_step: RunnableLambda.from(calculateAge),
* greeting_step: RunnableLambda.from(createGreeting),
* });
*
* const runnableAssign = new RunnableAssign({ mapper });
*
* const res = await runnableAssign.invoke({ name: "Alice", birthYear: 1990 });
*
* // { name: "Alice", birthYear: 1990, age_step: { age: 34 }, greeting_step: { greeting: "Hello, Alice!" } }
* ```
*/
var RunnableAssign = class extends Runnable {
static lc_name() {
return "RunnableAssign";
}
lc_namespace = ["langchain_core", "runnables"];
lc_serializable = true;
mapper;
constructor(fields) {
if (fields instanceof RunnableMap) fields = { mapper: fields };
super(fields);
this.mapper = fields.mapper;
}
async invoke(input, options) {
const mapperResult = await this.mapper.invoke(input, options);
return {
...input,
...mapperResult
};
}
async *_transform(generator, runManager, options) {
const mapperKeys = this.mapper.getStepsKeys();
const [forPassthrough, forMapper] = require_utils_stream.atee(generator);
const mapperOutput = this.mapper.transform(forMapper, require_config.patchConfig(options, { callbacks: runManager?.getChild() }));
const firstMapperChunkPromise = mapperOutput.next();
for await (const chunk of forPassthrough) {
if (typeof chunk !== "object" || Array.isArray(chunk)) throw new Error(`RunnableAssign can only be used with objects as input, got ${typeof chunk}`);
const filtered = Object.fromEntries(Object.entries(chunk).filter(([key]) => !mapperKeys.includes(key)));
if (Object.keys(filtered).length > 0) yield filtered;
}
yield (await firstMapperChunkPromise).value;
for await (const chunk of mapperOutput) yield chunk;
}
transform(generator, options) {
return this._transformStreamWithConfig(generator, this._transform.bind(this), options);
}
async stream(input, options) {
async function* generator() {
yield input;
}
const config = require_config.ensureConfig(options);
const wrappedGenerator = new require_utils_stream.AsyncGeneratorWithSetup({
generator: this.transform(generator(), config),
config
});
await wrappedGenerator.setup;
return require_utils_stream.IterableReadableStream.fromAsyncGenerator(wrappedGenerator);
}
};
/**
* A runnable that assigns key-value pairs to inputs of type `Record<string, unknown>`.
* Useful for streaming, can be automatically created and chained by calling `runnable.pick();`.
* @example
* ```typescript
* import { RunnablePick } from "@langchain/core/runnables";
*
* const inputData = {
* name: "John",
* age: 30,
* city: "New York",
* country: "USA",
* email: "john.doe@example.com",
* phone: "+1234567890",
* };
*
* const basicInfoRunnable = new RunnablePick(["name", "city"]);
*
* // Example invocation
* const res = await basicInfoRunnable.invoke(inputData);
*
* // { name: 'John', city: 'New York' }
* ```
*/
var RunnablePick = class extends Runnable {
static lc_name() {
return "RunnablePick";
}
lc_namespace = ["langchain_core", "runnables"];
lc_serializable = true;
keys;
constructor(fields) {
if (typeof fields === "string" || Array.isArray(fields)) fields = { keys: fields };
super(fields);
this.keys = fields.keys;
}
async _pick(input) {
if (typeof this.keys === "string") return input[this.keys];
else {
const picked = this.keys.map((key) => [key, input[key]]).filter((v) => v[1] !== void 0);
return picked.length === 0 ? void 0 : Object.fromEntries(picked);
}
}
async invoke(input, options) {
return this._callWithConfig(this._pick.bind(this), input, options);
}
async *_transform(generator) {
for await (const chunk of generator) {
const picked = await this._pick(chunk);
if (picked !== void 0) yield picked;
}
}
transform(generator, options) {
return this._transformStreamWithConfig(generator, this._transform.bind(this), options);
}
async stream(input, options) {
async function* generator() {
yield input;
}
const config = require_config.ensureConfig(options);
const wrappedGenerator = new require_utils_stream.AsyncGeneratorWithSetup({
generator: this.transform(generator(), config),
config
});
await wrappedGenerator.setup;
return require_utils_stream.IterableReadableStream.fromAsyncGenerator(wrappedGenerator);
}
};
var RunnableToolLike = class extends RunnableBinding {
name;
description;
schema;
constructor(fields) {
const sequence = RunnableSequence.from([RunnableLambda.from(async (input) => {
let toolInput;
if (require_utils._isToolCall(input)) try {
toolInput = await require_zod.interopParseAsync(this.schema, input.args);
} catch {
throw new require_utils.ToolInputParsingException(`Received tool input did not match expected schema`, JSON.stringify(input.args));
}
else toolInput = input;
return toolInput;
}).withConfig({ runName: `${fields.name}:parse_input` }), fields.bound]).withConfig({ runName: fields.name });
super({
bound: sequence,
config: fields.config ?? {}
});
this.name = fields.name;
this.description = fields.description;
this.schema = fields.schema;
}
static lc_name() {
return "RunnableToolLike";
}
};
/**
* Given a runnable and a Zod schema, convert the runnable to a tool.
*
* @template RunInput The input type for the runnable.
* @template RunOutput The output type for the runnable.
*
* @param {Runnable<RunInput, RunOutput>} runnable The runnable to convert to a tool.
* @param fields
* @param {string | undefined} [fields.name] The name of the tool. If not provided, it will default to the name of the runnable.
* @param {string | undefined} [fields.description] The description of the tool. Falls back to the description on the Zod schema if not provided, or undefined if neither are provided.
* @param {InteropZodType<RunInput>} [fields.schema] The Zod schema for the input of the tool. Infers the Zod type from the input type of the runnable.
* @returns {RunnableToolLike<InteropZodType<RunInput>, RunOutput>} An instance of `RunnableToolLike` which is a runnable that can be used as a tool.
*/
function convertRunnableToTool(runnable, fields) {
const name = fields.name ?? runnable.getName();
const description = fields.description ?? require_zod.getSchemaDescription(fields.schema);
if (require_zod.isSimpleStringZodSchema(fields.schema)) return new RunnableToolLike({
name,
description,
schema: zod_v3.z.object({ input: zod_v3.z.string() }).transform((input) => input.input),
bound: runnable
});
return new RunnableToolLike({
name,
description,
schema: fields.schema,
bound: runnable
});
}
//#endregion
exports.Runnable = Runnable;
exports.RunnableAssign = RunnableAssign;
exports.RunnableBinding = RunnableBinding;
exports.RunnableEach = RunnableEach;
exports.RunnableLambda = RunnableLambda;
exports.RunnableMap = RunnableMap;
exports.RunnableParallel = RunnableParallel;
exports.RunnablePick = RunnablePick;
exports.RunnableRetry = RunnableRetry;
exports.RunnableSequence = RunnableSequence;
exports.RunnableToolLike = RunnableToolLike;
exports.RunnableTraceable = RunnableTraceable;
exports.RunnableWithFallbacks = RunnableWithFallbacks;
exports._coerceToDict = _coerceToDict;
exports._coerceToRunnable = _coerceToRunnable;
exports.convertRunnableToTool = convertRunnableToTool;
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