@langchain/langgraph
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439 lines (438 loc) • 17 kB
JavaScript
import { CONFIG_KEY_STREAM, INTERRUPT, isCommand } from "../constants.js";
import { GraphInterrupt, RemoteException } from "../errors.js";
import { propagateConfigurableToMetadata } from "./utils/config.js";
import { IterableReadableStreamWithAbortSignal } from "./stream.js";
import "../web.js";
import { RemoteGraphRunStream } from "./remote-run-stream.js";
import { Runnable, mergeConfigs } from "@langchain/core/runnables";
import { Graph } from "@langchain/core/runnables/graph";
import { BaseMessage } from "@langchain/core/messages";
import { Client } from "@langchain/langgraph-sdk";
//#region src/pregel/remote.ts
const _serializeInputs = (obj) => {
if (obj === null || typeof obj !== "object") return obj;
if (Array.isArray(obj)) return obj.map(_serializeInputs);
if (BaseMessage.isInstance(obj)) return {
...obj.toDict().data,
role: obj.getType()
};
return Object.fromEntries(Object.entries(obj).map(([key, value]) => [key, _serializeInputs(value)]));
};
/**
* Return a tuple of the final list of stream modes sent to the
* remote graph and a boolean flag indicating if only one stream mode was
* originally requested and whether stream mode 'updates'
* was present in the original list of stream modes.
*
* 'updates' mode is always added to the list of stream modes so that interrupts
* can be detected in the remote graph.
*/
const getStreamModes = (streamMode, defaultStreamMode = "updates") => {
const updatedStreamModes = [];
let reqUpdates = false;
let reqSingle = true;
if (streamMode !== void 0 && (typeof streamMode === "string" || Array.isArray(streamMode) && streamMode.length > 0)) {
reqSingle = typeof streamMode === "string";
const mapped = Array.isArray(streamMode) ? streamMode : [streamMode];
updatedStreamModes.push(...mapped);
} else updatedStreamModes.push(defaultStreamMode);
if (updatedStreamModes.includes("updates")) reqUpdates = true;
else updatedStreamModes.push("updates");
return {
updatedStreamModes,
reqUpdates,
reqSingle
};
};
function protocolEventsToEventStream(run) {
const encoder = new TextEncoder();
return new ReadableStream({ async start(controller) {
try {
for await (const event of run) {
const namespace = event.params.namespace;
const eventName = namespace.length ? `${event.method}|${namespace.join("|")}` : event.method;
controller.enqueue(encoder.encode(`event: ${eventName}\ndata: ${JSON.stringify(event.params.data ?? {})}\n\n`));
}
} catch (error) {
controller.enqueue(encoder.encode(`event: error\ndata: ${JSON.stringify({ message: String(error) })}\n\n`));
} finally {
controller.close();
}
} });
}
/**
* The `RemoteGraph` class is a client implementation for calling remote
* APIs that implement the LangGraph Server API specification.
*
* For example, the `RemoteGraph` class can be used to call APIs from deployments
* on LangSmith Deployment.
*
* `RemoteGraph` behaves the same way as a `StateGraph` and can be used directly as
* a node in another `StateGraph`.
*
* @example
* ```ts
* import { RemoteGraph } from "@langchain/langgraph/remote";
*
* // Can also pass a LangGraph SDK client instance directly
* const remoteGraph = new RemoteGraph({
* graphId: process.env.LANGGRAPH_REMOTE_GRAPH_ID!,
* apiKey: process.env.LANGGRAPH_REMOTE_GRAPH_API_KEY,
* url: process.env.LANGGRAPH_REMOTE_GRAPH_API_URL,
* });
*
* const input = {
* messages: [
* {
* role: "human",
* content: "Hello world!",
* },
* ],
* };
*
* const config = {
* configurable: { thread_id: "threadId1" },
* };
*
* await remoteGraph.invoke(input, config);
* ```
*/
var RemoteGraph = class extends Runnable {
static lc_name() {
return "RemoteGraph";
}
lc_namespace = ["langgraph", "pregel"];
lg_is_pregel = true;
config;
graphId;
client;
interruptBefore;
interruptAfter;
streamResumable;
constructor(params) {
super(params);
this.graphId = params.graphId;
this.client = params.client ?? new Client({
apiUrl: params.url,
apiKey: params.apiKey,
defaultHeaders: params.headers
});
this.config = params.config;
this.interruptBefore = params.interruptBefore;
this.interruptAfter = params.interruptAfter;
this.streamResumable = params.streamResumable;
}
withConfig(config) {
const mergedConfig = mergeConfigs(this.config, config);
return new this.constructor({
...this,
config: mergedConfig
});
}
_sanitizeConfig(config) {
const reservedConfigurableKeys = new Set([
"callbacks",
"checkpoint_map",
"checkpoint_id",
"checkpoint_ns"
]);
const sanitizeObj = (obj) => {
try {
JSON.stringify(obj);
return obj;
} catch {
const seen = /* @__PURE__ */ new WeakSet();
return JSON.parse(JSON.stringify(obj, (_, value) => {
if (typeof value === "object" && value != null) {
if (seen.has(value)) return "[Circular]";
seen.add(value);
}
if (typeof value === "bigint") return value.toString();
return value;
}));
}
};
const propagateMetadataDefaults = (obj) => {
const seen = /* @__PURE__ */ new WeakSet();
const visit = (value) => {
if (typeof value !== "object" || value == null) return;
if (seen.has(value)) return;
seen.add(value);
const record = value;
const configurable = record.configurable;
if (typeof configurable === "object" && configurable != null && !Array.isArray(configurable)) record.metadata = propagateConfigurableToMetadata(configurable, typeof record.metadata === "object" && record.metadata != null && !Array.isArray(record.metadata) ? record.metadata : void 0) ?? record.metadata;
for (const nestedValue of Object.values(record)) visit(nestedValue);
};
visit(obj);
};
propagateMetadataDefaults(config);
const sanitizedConfig = sanitizeObj(config);
const newConfigurable = Object.fromEntries(Object.entries(sanitizedConfig.configurable ?? {}).filter(([k]) => !reservedConfigurableKeys.has(k) && !k.startsWith("__pregel_")));
return {
tags: sanitizedConfig.tags ?? [],
metadata: sanitizedConfig.metadata ?? {},
configurable: newConfigurable,
recursion_limit: sanitizedConfig.recursionLimit
};
}
/**
* Prepare config and thread ID for remote run API calls.
*
* `thread_id` is passed via the URL path, not in `config.configurable`, so the
* server can accept a separate `context` payload for stateful runs.
*/
#prepareRunRequest(mergedConfig) {
const context = mergedConfig.context;
const sanitizedConfig = this._sanitizeConfig(mergedConfig);
const configurable = { ...sanitizedConfig.configurable };
const threadId = configurable.thread_id;
delete configurable.thread_id;
return {
threadId,
context,
config: {
...sanitizedConfig,
configurable
}
};
}
_getConfig(checkpoint) {
return { configurable: {
thread_id: checkpoint.thread_id,
checkpoint_ns: checkpoint.checkpoint_ns,
checkpoint_id: checkpoint.checkpoint_id,
checkpoint_map: checkpoint.checkpoint_map ?? {}
} };
}
_checkpointToConfig(checkpoint, fallbackConfig) {
const resolvedCheckpoint = checkpoint ?? this._getCheckpoint(fallbackConfig);
if (resolvedCheckpoint == null) return { configurable: {} };
const configurable = {};
if (resolvedCheckpoint.thread_id !== void 0) configurable.thread_id = resolvedCheckpoint.thread_id;
if (resolvedCheckpoint.checkpoint_ns !== void 0) configurable.checkpoint_ns = resolvedCheckpoint.checkpoint_ns;
if (resolvedCheckpoint.checkpoint_id !== void 0) configurable.checkpoint_id = resolvedCheckpoint.checkpoint_id;
if (resolvedCheckpoint.checkpoint_ns !== void 0 || resolvedCheckpoint.checkpoint_id !== void 0 || resolvedCheckpoint.checkpoint_map !== void 0) configurable.checkpoint_map = resolvedCheckpoint.checkpoint_map ?? {};
return { configurable };
}
_getCheckpoint(config) {
if (config?.configurable === void 0) return;
const checkpoint = Object.fromEntries([
"thread_id",
"checkpoint_ns",
"checkpoint_id",
"checkpoint_map"
].map((key) => [key, config.configurable[key]]).filter(([_, value]) => value !== void 0));
return Object.keys(checkpoint).length > 0 ? checkpoint : void 0;
}
_createStateSnapshot(state, fallbackConfig) {
const tasks = state.tasks.map((task) => {
return {
id: task.id,
name: task.name,
error: task.error ? { message: task.error } : void 0,
interrupts: task.interrupts.map(({ id, ...rest }) => ({
interrupt_id: id,
...rest
})),
state: task.state ? this._createStateSnapshot(task.state, task.checkpoint ? this._checkpointToConfig(task.checkpoint) : fallbackConfig) : task.checkpoint ? { configurable: task.checkpoint } : void 0,
result: task.result
};
});
return {
values: state.values,
next: state.next ? [...state.next] : [],
config: this._checkpointToConfig(state.checkpoint, fallbackConfig),
metadata: state.metadata ? state.metadata : void 0,
createdAt: state.created_at ?? void 0,
parentConfig: state.parent_checkpoint ? this._checkpointToConfig(state.parent_checkpoint) : void 0,
tasks
};
}
async invoke(input, options) {
let lastValue;
const stream = await this.stream(input, {
...options,
streamMode: "values"
});
for await (const chunk of stream) lastValue = chunk;
return lastValue;
}
streamEvents(input, options, _streamOptions) {
if (options.version === "v3") return this._streamEventsV3(input, options);
throw new Error("Not implemented.");
}
_rejectV3Unsupported(options) {
if (options.transformers !== void 0) throw new Error("RemoteGraph.streamEvents({ version: \"v3\" }) does not support `transformers`.");
if (options.control !== void 0) throw new Error("RemoteGraph.streamEvents({ version: \"v3\" }) does not support `control`.");
if (options.interruptBefore !== void 0 || this.interruptBefore !== void 0) throw new Error("RemoteGraph.streamEvents({ version: \"v3\" }) does not support `interruptBefore`.");
if (options.interruptAfter !== void 0 || this.interruptAfter !== void 0) throw new Error("RemoteGraph.streamEvents({ version: \"v3\" }) does not support `interruptAfter`.");
}
async _streamEventsV3(input, options) {
this._rejectV3Unsupported(options);
const abortController = new AbortController();
const mergedConfig = mergeConfigs(this.config, options);
const sanitizedConfig = this._sanitizeConfig(mergedConfig);
const configurable = { ...sanitizedConfig.configurable };
const threadId = configurable.thread_id;
delete configurable.thread_id;
const runConfig = {
...sanitizedConfig,
configurable
};
const thread = typeof threadId === "string" ? this.client.threads.stream(threadId, { assistantId: this.graphId }) : this.client.threads.stream({ assistantId: this.graphId });
let serializedInput;
if (isCommand(input)) serializedInput = input.toJSON();
else serializedInput = _serializeInputs(input);
const run = await thread.run.start({
input: serializedInput,
config: runConfig
});
const graphRun = new RemoteGraphRunStream({
client: this.client,
thread,
runId: run.run_id,
abortController
});
if (mergedConfig.signal != null) if (mergedConfig.signal.aborted) graphRun.abort(mergedConfig.signal.reason);
else mergedConfig.signal.addEventListener("abort", () => graphRun.abort(mergedConfig.signal?.reason), { once: true });
if (options.encoding === "text/event-stream") {
const encodingAbortController = new AbortController();
encodingAbortController.signal.addEventListener("abort", () => graphRun.abort(encodingAbortController.signal.reason), { once: true });
return new IterableReadableStreamWithAbortSignal(protocolEventsToEventStream(graphRun), encodingAbortController);
}
return graphRun;
}
async *_streamIterator(input, options) {
const mergedConfig = mergeConfigs(this.config, options);
const { threadId, context, config: sanitizedConfig } = this.#prepareRunRequest(mergedConfig);
const streamProtocolInstance = options?.configurable?.[CONFIG_KEY_STREAM];
const streamSubgraphs = options?.subgraphs ?? streamProtocolInstance !== void 0;
const interruptBefore = options?.interruptBefore ?? this.interruptBefore;
const interruptAfter = options?.interruptAfter ?? this.interruptAfter;
const { updatedStreamModes, reqSingle, reqUpdates } = getStreamModes(options?.streamMode);
const extendedStreamModes = [...new Set([...updatedStreamModes, ...streamProtocolInstance?.modes ?? /* @__PURE__ */ new Set()])].map((mode) => {
if (mode === "messages") return "messages-tuple";
return mode;
});
let command;
let serializedInput;
if (isCommand(input)) {
command = input.toJSON();
serializedInput = void 0;
} else serializedInput = _serializeInputs(input);
const streamPayload = {
command,
input: serializedInput,
config: sanitizedConfig,
context,
streamMode: extendedStreamModes,
interruptBefore,
interruptAfter,
streamSubgraphs,
ifNotExists: "create",
signal: mergedConfig.signal,
streamResumable: this.streamResumable
};
const runStream = threadId != null ? this.client.runs.stream(threadId, this.graphId, streamPayload) : this.client.runs.stream(null, this.graphId, streamPayload);
for await (const chunk of runStream) {
let mode;
let namespace;
if (chunk.event.includes("|")) {
const eventComponents = chunk.event.split("|");
mode = eventComponents[0];
namespace = eventComponents.slice(1);
} else {
mode = chunk.event;
namespace = [];
}
const callerNamespace = options?.configurable?.checkpoint_ns;
if (typeof callerNamespace === "string") namespace = callerNamespace.split("|").concat(namespace);
if (streamProtocolInstance !== void 0 && streamProtocolInstance.modes?.has(chunk.event)) streamProtocolInstance.push([
namespace,
mode,
chunk.data
]);
if (chunk.event.startsWith("updates")) {
if (typeof chunk.data === "object" && chunk.data?.["__interrupt__"] !== void 0) throw new GraphInterrupt(chunk.data[INTERRUPT]);
if (!reqUpdates) continue;
} else if (chunk.event?.startsWith("error")) throw new RemoteException(typeof chunk.data === "string" ? chunk.data : JSON.stringify(chunk.data));
if (!updatedStreamModes.includes(chunk.event.split("|")[0])) continue;
if (options?.subgraphs) if (reqSingle) yield [namespace, chunk.data];
else yield [
namespace,
mode,
chunk.data
];
else if (reqSingle) yield chunk.data;
else yield [mode, chunk.data];
}
}
async updateState(inputConfig, values, asNode) {
const mergedConfig = mergeConfigs(this.config, inputConfig);
const response = await this.client.threads.updateState(mergedConfig.configurable?.thread_id, {
values,
asNode,
checkpoint: this._getCheckpoint(mergedConfig)
});
return this._getConfig(response.checkpoint);
}
async *getStateHistory(config, options) {
const mergedConfig = mergeConfigs(this.config, config);
const states = await this.client.threads.getHistory(mergedConfig.configurable?.thread_id, {
limit: options?.limit ?? 10,
before: this._getCheckpoint(options?.before),
metadata: options?.filter,
checkpoint: this._getCheckpoint(mergedConfig)
});
for (const state of states) yield this._createStateSnapshot(state, mergedConfig);
}
_getDrawableNodes(nodes) {
const nodesMap = {};
for (const node of nodes) {
const nodeId = node.id;
nodesMap[nodeId] = {
id: nodeId.toString(),
name: typeof node.data === "string" ? node.data : node.data?.name ?? "",
data: node.data ?? {},
metadata: typeof node.data !== "string" ? node.data?.metadata ?? {} : {}
};
}
return nodesMap;
}
async getState(config, options) {
const mergedConfig = mergeConfigs(this.config, config);
const state = await this.client.threads.getState(mergedConfig.configurable?.thread_id, this._getCheckpoint(mergedConfig), options);
return this._createStateSnapshot(state, mergedConfig);
}
/** @deprecated Use getGraphAsync instead. The async method will become the default in the next minor release. */
getGraph(_) {
throw new Error(`The synchronous "getGraph" is not supported for this graph. Call "getGraphAsync" instead.`);
}
/**
* Returns a drawable representation of the computation graph.
*/
async getGraphAsync(config) {
const graph = await this.client.assistants.getGraph(this.graphId, { xray: config?.xray });
return new Graph({
nodes: this._getDrawableNodes(graph.nodes),
edges: graph.edges
});
}
/** @deprecated Use getSubgraphsAsync instead. The async method will become the default in the next minor release. */
getSubgraphs() {
throw new Error(`The synchronous "getSubgraphs" method is not supported for this graph. Call "getSubgraphsAsync" instead.`);
}
async *getSubgraphsAsync(namespace, recurse = false) {
const subgraphs = await this.client.assistants.getSubgraphs(this.graphId, {
namespace,
recurse
});
for (const [ns, graphSchema] of Object.entries(subgraphs)) yield [ns, new this.constructor({
...this,
graphId: graphSchema.graph_id
})];
}
};
//#endregion
export { RemoteGraph };
//# sourceMappingURL=remote.js.map