@langchain/langgraph
Version:
LangGraph
345 lines (343 loc) • 12 kB
JavaScript
import { GraphInterrupt, RemoteException } from "../errors.js";
import { CHECKPOINT_NAMESPACE_SEPARATOR, CONFIG_KEY_STREAM, INTERRUPT, isCommand } from "../constants.js";
import "../web.js";
import { Runnable, mergeConfigs } from "@langchain/core/runnables";
import { Graph } from "@langchain/core/runnables/graph";
import { isBaseMessage } 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 (isBaseMessage(obj)) {
const dict = obj.toDict();
return {
...dict.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
};
};
/**
* 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 LangGraph Cloud.
*
* `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;
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;
}
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 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
};
}
_getConfig(checkpoint) {
return { configurable: {
thread_id: checkpoint.thread_id,
checkpoint_ns: checkpoint.checkpoint_ns,
checkpoint_id: checkpoint.checkpoint_id,
checkpoint_map: checkpoint.checkpoint_map ?? {}
} };
}
_getCheckpoint(config) {
if (config?.configurable === void 0) return void 0;
const checkpointKeys = [
"thread_id",
"checkpoint_ns",
"checkpoint_id",
"checkpoint_map"
];
const checkpoint = Object.fromEntries(checkpointKeys.map((key) => [key, config.configurable[key]]).filter(([_, value]) => value !== void 0));
return Object.keys(checkpoint).length > 0 ? checkpoint : void 0;
}
_createStateSnapshot(state) {
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 ? { configurable: task.checkpoint } : void 0,
result: task.result
};
});
return {
values: state.values,
next: state.next ? [...state.next] : [],
config: { configurable: {
thread_id: state.checkpoint.thread_id,
checkpoint_ns: state.checkpoint.checkpoint_ns,
checkpoint_id: state.checkpoint.checkpoint_id,
checkpoint_map: state.checkpoint.checkpoint_map ?? {}
} },
metadata: state.metadata ? state.metadata : void 0,
createdAt: state.created_at ?? void 0,
parentConfig: state.parent_checkpoint ? { configurable: {
thread_id: state.parent_checkpoint.thread_id,
checkpoint_ns: state.parent_checkpoint.checkpoint_ns,
checkpoint_id: state.parent_checkpoint.checkpoint_id,
checkpoint_map: state.parent_checkpoint.checkpoint_map ?? {}
} } : 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) {
throw new Error("Not implemented.");
}
async *_streamIterator(input, options) {
const mergedConfig = mergeConfigs(this.config, options);
const sanitizedConfig = this._sanitizeConfig(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);
for await (const chunk of this.client.runs.stream(sanitizedConfig.configurable.thread_id, this.graphId, {
command,
input: serializedInput,
config: sanitizedConfig,
streamMode: extendedStreamModes,
interruptBefore,
interruptAfter,
streamSubgraphs,
ifNotExists: "create",
signal: mergedConfig.signal
})) {
let mode;
let namespace;
if (chunk.event.includes(CHECKPOINT_NAMESPACE_SEPARATOR)) {
const eventComponents = chunk.event.split(CHECKPOINT_NAMESPACE_SEPARATOR);
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(CHECKPOINT_NAMESPACE_SEPARATOR).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(CHECKPOINT_NAMESPACE_SEPARATOR)[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);
}
_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);
}
/** @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)) {
const remoteSubgraph = new this.constructor({
...this,
graphId: graphSchema.graph_id
});
yield [ns, remoteSubgraph];
}
}
};
//#endregion
export { RemoteGraph };
//# sourceMappingURL=remote.js.map