@langchain/langgraph/dist/pregel/index.cjs.map

LangGraph

{"version":3,"file":"index.cjs","names":["channelMappingOrArray: string[] | Record<string, string>","triggers: string[]","PregelNode","channelWriteEntries: Array<ChannelWriteEntry>","PASSTHROUGH","Runnable","ChannelWrite","TASKS","Topic","findSubgraphPregel","CHECKPOINT_NAMESPACE_SEPARATOR","emptyChannels","NULL_TASK_ID","INPUT","_prepareNextTasks","gatherIterator","taskStates: Record<string, RunnableConfig | StateSnapshot>","CHECKPOINT_NAMESPACE_END","config: RunnableConfig","config","subgraphConfig: RunnableConfig","CONFIG_KEY_CHECKPOINTER","ERROR","INTERRUPT","SCHEDULED","tasksWithWrites","readChannels","patchCheckpointMap","GraphValueError","checkpointNamespace: string","recastCheckpointNamespace","patchConfigurable","checkpointer: BaseCheckpointSaver","checkpointer: BaseCheckpointSaver | undefined","InvalidUpdateError","nextConfig","createCheckpoint","END","getNewChannelVersions","COPY","values","asNode","mapInput","tasks","validUpdates: Array<{\n        values: Record<string, unknown> | unknown;\n        asNode: keyof Nodes | string;\n        taskId?: string;\n      }>","tasks: PregelExecutableTask<keyof Nodes, keyof Channels>[]","RunnableSequence","CONFIG_KEY_SEND","CONFIG_KEY_READ","_localRead","PUSH","defaultStreamMode: StreamMode[]","CONFIG_KEY_TASK_ID","defaultCheckpointer: BaseCheckpointSaver | undefined","defaultStore: BaseStore | undefined","defaultCache: BaseCache | undefined","checkpointDuringDurability: Durability | undefined","defaultDurability: Durability","CONFIG_KEY_DURABILITY","combineAbortSignals","IterableReadableStreamWithAbortSignal","toEventStream","combineCallbacks","ensureLangGraphConfig","IterableReadableWritableStream","ns: string","CONFIG_KEY_CHECKPOINT_NS","StreamMessagesHandler","getConfig","interrupt","_coerceToDict","getOnlyChannels","loop: PregelLoop | undefined","loopError: unknown","PregelLoop","PregelRunner","CONFIG_KEY_NODE_FINISHED","CONFIG_KEY_STREAM","interruptChunks: Interrupt[][]","latest: OutputType | undefined","isInterrupted","GraphRecursionError"],"sources":["../../src/pregel/index.ts"],"sourcesContent":["/* eslint-disable no-param-reassign */\nimport {\n  _coerceToRunnable,\n  getCallbackManagerForConfig,\n  mergeConfigs,\n  patchConfig,\n  Runnable,\n  RunnableConfig,\n  RunnableFunc,\n  RunnableLike,\n  RunnableSequence,\n} from \"@langchain/core/runnables\";\nimport type { StreamEvent } from \"@langchain/core/tracers/log_stream\";\nimport { IterableReadableStream } from \"@langchain/core/utils/stream\";\nimport {\n  All,\n  BaseCache,\n  BaseCheckpointSaver,\n  BaseStore,\n  CheckpointListOptions,\n  CheckpointMetadata,\n  CheckpointTuple,\n  compareChannelVersions,\n  copyCheckpoint,\n  emptyCheckpoint,\n  PendingWrite,\n  SCHEDULED,\n  SendProtocol,\n  uuid5,\n} from \"@langchain/langgraph-checkpoint\";\nimport {\n  BaseChannel,\n  createCheckpoint,\n  emptyChannels,\n  getOnlyChannels,\n} from \"../channels/base.js\";\nimport {\n  CHECKPOINT_NAMESPACE_END,\n  CHECKPOINT_NAMESPACE_SEPARATOR,\n  Command,\n  CONFIG_KEY_CHECKPOINTER,\n  CONFIG_KEY_NODE_FINISHED,\n  CONFIG_KEY_READ,\n  CONFIG_KEY_SEND,\n  CONFIG_KEY_STREAM,\n  CONFIG_KEY_TASK_ID,\n  COPY,\n  END,\n  ERROR,\n  INPUT,\n  INTERRUPT,\n  Interrupt,\n  isInterrupted,\n  NULL_TASK_ID,\n  PUSH,\n  CONFIG_KEY_DURABILITY,\n  CONFIG_KEY_CHECKPOINT_NS,\n  type CommandInstance,\n  TASKS,\n} from \"../constants.js\";\nimport {\n  GraphRecursionError,\n  GraphValueError,\n  InvalidUpdateError,\n} from \"../errors.js\";\nimport { gatherIterator, patchConfigurable } from \"../utils.js\";\nimport {\n  _applyWrites,\n  _localRead,\n  _prepareNextTasks,\n  StrRecord,\n  WritesProtocol,\n} from \"./algo.js\";\nimport {\n  printStepCheckpoint,\n  printStepTasks,\n  printStepWrites,\n  tasksWithWrites,\n} from \"./debug.js\";\nimport { mapInput, readChannels } from \"./io.js\";\nimport { PregelLoop } from \"./loop.js\";\nimport { StreamMessagesHandler } from \"./messages.js\";\nimport { PregelNode } from \"./read.js\";\nimport { LangGraphRunnableConfig } from \"./runnable_types.js\";\nimport { PregelRunner } from \"./runner.js\";\nimport {\n  IterableReadableStreamWithAbortSignal,\n  IterableReadableWritableStream,\n  toEventStream,\n} from \"./stream.js\";\nimport type {\n  Durability,\n  GetStateOptions,\n  MultipleChannelSubscriptionOptions,\n  PregelExecutableTask,\n  PregelInputType,\n  PregelInterface,\n  PregelOptions,\n  PregelOutputType,\n  PregelParams,\n  SingleChannelSubscriptionOptions,\n  StateSnapshot,\n  StreamMode,\n  StreamOutputMap,\n} from \"./types.js\";\nimport {\n  ensureLangGraphConfig,\n  getConfig,\n  recastCheckpointNamespace,\n} from \"./utils/config.js\";\nimport {\n  _coerceToDict,\n  combineAbortSignals,\n  combineCallbacks,\n  getNewChannelVersions,\n  patchCheckpointMap,\n  RetryPolicy,\n} from \"./utils/index.js\";\nimport { findSubgraphPregel } from \"./utils/subgraph.js\";\nimport { validateGraph, validateKeys } from \"./validate.js\";\nimport { ChannelWrite, ChannelWriteEntry, PASSTHROUGH } from \"./write.js\";\nimport { Topic } from \"../channels/topic.js\";\nimport { interrupt } from \"../interrupt.js\";\n\ntype WriteValue = Runnable | RunnableFunc<unknown, unknown> | unknown;\ntype StreamEventsOptions = Parameters<Runnable[\"streamEvents\"]>[2];\n\n/**\n * Utility class for working with channels in the Pregel system.\n * Provides static methods for subscribing to channels and writing to them.\n *\n * Channels are the communication pathways between nodes in a Pregel graph.\n * They enable message passing and state updates between different parts of the graph.\n */\nexport class Channel {\n  /**\n   * Creates a PregelNode that subscribes to a single channel.\n   * This is used to define how nodes receive input from channels.\n   *\n   * @example\n   * ```typescript\n   * // Subscribe to a single channel\n   * const node = Channel.subscribeTo(\"messages\");\n   *\n   * // Subscribe to multiple channels\n   * const node = Channel.subscribeTo([\"messages\", \"state\"]);\n   *\n   * // Subscribe with a custom key\n   * const node = Channel.subscribeTo(\"messages\", { key: \"chat\" });\n   * ```\n   *\n   * @param channel Single channel name to subscribe to\n   * @param options Subscription options\n   * @returns A PregelNode configured to receive from the specified channels\n   * @throws {Error} If a key is specified when subscribing to multiple channels\n   */\n  static subscribeTo(\n    channel: string,\n    options?: SingleChannelSubscriptionOptions\n  ): PregelNode;\n\n  /**\n   * Creates a PregelNode that subscribes to multiple channels.\n   * This is used to define how nodes receive input from channels.\n   *\n   * @example\n   * ```typescript\n   * // Subscribe to a single channel\n   * const node = Channel.subscribeTo(\"messages\");\n   *\n   * // Subscribe to multiple channels\n   * const node = Channel.subscribeTo([\"messages\", \"state\"]);\n   *\n   * // Subscribe with a custom key\n   * const node = Channel.subscribeTo(\"messages\", { key: \"chat\" });\n   * ```\n   *\n   * @param channels Single channel name to subscribe to\n   * @param options Subscription options\n   * @returns A PregelNode configured to receive from the specified channels\n   * @throws {Error} If a key is specified when subscribing to multiple channels\n   */\n  static subscribeTo(\n    channels: string[],\n    options?: MultipleChannelSubscriptionOptions\n  ): PregelNode;\n\n  static subscribeTo(\n    channels: string | string[],\n    options?:\n      | SingleChannelSubscriptionOptions\n      | MultipleChannelSubscriptionOptions\n  ): PregelNode {\n    const { key, tags } = {\n      key: undefined,\n      tags: undefined,\n      ...(options ?? {}),\n    };\n    if (Array.isArray(channels) && key !== undefined) {\n      throw new Error(\n        \"Can't specify a key when subscribing to multiple channels\"\n      );\n    }\n\n    let channelMappingOrArray: string[] | Record<string, string>;\n\n    if (typeof channels === \"string\") {\n      if (key) {\n        channelMappingOrArray = { [key]: channels };\n      } else {\n        channelMappingOrArray = [channels];\n      }\n    } else {\n      channelMappingOrArray = Object.fromEntries(\n        channels.map((chan) => [chan, chan])\n      );\n    }\n\n    const triggers: string[] = Array.isArray(channels) ? channels : [channels];\n\n    return new PregelNode({\n      channels: channelMappingOrArray,\n      triggers,\n      tags,\n    });\n  }\n\n  /**\n   * Creates a ChannelWrite that specifies how to write values to channels.\n   * This is used to define how nodes send output to channels.\n   *\n   * @example\n   * ```typescript\n   * // Write to multiple channels\n   * const write = Channel.writeTo([\"output\", \"state\"]);\n   *\n   * // Write with specific values\n   * const write = Channel.writeTo([\"output\"], {\n   *   state: \"completed\",\n   *   result: calculateResult()\n   * });\n   *\n   * // Write with a transformation function\n   * const write = Channel.writeTo([\"output\"], {\n   *   result: (x) => processResult(x)\n   * });\n   * ```\n   *\n   * @param channels - Array of channel names to write to\n   * @param writes - Optional map of channel names to values or transformations\n   * @returns A ChannelWrite object that can be used to write to the specified channels\n   */\n  static writeTo(\n    channels: string[],\n    writes?: Record<string, WriteValue>\n  ): ChannelWrite {\n    const channelWriteEntries: Array<ChannelWriteEntry> = [];\n\n    for (const channel of channels) {\n      channelWriteEntries.push({\n        channel,\n        value: PASSTHROUGH,\n        skipNone: false,\n      });\n    }\n\n    for (const [key, value] of Object.entries(writes ?? {})) {\n      if (Runnable.isRunnable(value) || typeof value === \"function\") {\n        channelWriteEntries.push({\n          channel: key,\n          value: PASSTHROUGH,\n          skipNone: true,\n          mapper: _coerceToRunnable(value as RunnableLike),\n        });\n      } else {\n        channelWriteEntries.push({\n          channel: key,\n          value,\n          skipNone: false,\n        });\n      }\n    }\n\n    return new ChannelWrite(channelWriteEntries);\n  }\n}\n\nexport type { PregelInputType, PregelOptions, PregelOutputType };\n\n// This is a workaround to allow Pregel to override `invoke` / `stream` and `withConfig`\n// without having to adhere to the types in the `Runnable` class (thanks to `any`).\n// Alternatively we could mark those methods with @ts-ignore / @ts-expect-error,\n// but these do not get carried over when building via `tsc`.\nclass PartialRunnable<\n  RunInput,\n  RunOutput,\n  CallOptions extends RunnableConfig\n> extends Runnable<RunInput, RunOutput, CallOptions> {\n  lc_namespace = [\"langgraph\", \"pregel\"];\n\n  override invoke(\n    _input: RunInput,\n    _options?: Partial<CallOptions>\n    // eslint-disable-next-line @typescript-eslint/no-explicit-any\n  ): Promise<any> {\n    throw new Error(\"Not implemented\");\n  }\n\n  // Overriden by `Pregel`\n  override withConfig(_config: CallOptions): typeof this {\n    return super.withConfig(_config) as typeof this;\n  }\n\n  // Overriden by `Pregel`\n  override stream(\n    input: RunInput,\n    options?: Partial<CallOptions>\n    // eslint-disable-next-line @typescript-eslint/no-explicit-any\n  ): Promise<IterableReadableStream<any>> {\n    return super.stream(input, options);\n  }\n}\n\n/**\n * The Pregel class is the core runtime engine of LangGraph, implementing a message-passing graph computation model\n * inspired by [Google's Pregel system](https://research.google/pubs/pregel-a-system-for-large-scale-graph-processing/).\n * It provides the foundation for building reliable, controllable agent workflows that can evolve state over time.\n *\n * Key features:\n * - Message passing between nodes in discrete \"supersteps\"\n * - Built-in persistence layer through checkpointers\n * - First-class streaming support for values, updates, and events\n * - Human-in-the-loop capabilities via interrupts\n * - Support for parallel node execution within supersteps\n *\n * The Pregel class is not intended to be instantiated directly by consumers. Instead, use the following higher-level APIs:\n * - {@link StateGraph}: The main graph class for building agent workflows\n *   - Compiling a {@link StateGraph} will return a {@link CompiledGraph} instance, which extends `Pregel`\n * - Functional API: A declarative approach using tasks and entrypoints\n *   - A `Pregel` instance is returned by the {@link entrypoint} function\n *\n * @example\n * ```typescript\n * // Using StateGraph API\n * const graph = new StateGraph(annotation)\n *   .addNode(\"nodeA\", myNodeFunction)\n *   .addEdge(\"nodeA\", \"nodeB\")\n *   .compile();\n *\n * // The compiled graph is a Pregel instance\n * const result = await graph.invoke(input);\n * ```\n *\n * @example\n * ```typescript\n * // Using Functional API\n * import { task, entrypoint } from \"@langchain/langgraph\";\n * import { MemorySaver } from \"@langchain/langgraph-checkpoint\";\n *\n * // Define tasks that can be composed\n * const addOne = task(\"add\", async (x: number) => x + 1);\n *\n * // Create a workflow using the entrypoint function\n * const workflow = entrypoint({\n *   name: \"workflow\",\n *   checkpointer: new MemorySaver()\n * }, async (numbers: number[]) => {\n *   // Tasks can be run in parallel\n *   const results = await Promise.all(numbers.map(n => addOne(n)));\n *   return results;\n * });\n *\n * // The workflow is a Pregel instance\n * const result = await workflow.invoke([1, 2, 3]); // Returns [2, 3, 4]\n * ```\n *\n * @typeParam Nodes - Mapping of node names to their {@link PregelNode} implementations\n * @typeParam Channels - Mapping of channel names to their {@link BaseChannel} or {@link ManagedValueSpec} implementations\n * @typeParam ContextType - Type of context that can be passed to the graph\n * @typeParam InputType - Type of input values accepted by the graph\n * @typeParam OutputType - Type of output values produced by the graph\n */\nexport class Pregel<\n    Nodes extends StrRecord<string, PregelNode>,\n    Channels extends StrRecord<string, BaseChannel>,\n    // eslint-disable-next-line @typescript-eslint/no-explicit-any\n    ContextType extends Record<string, any> = StrRecord<string, any>,\n    InputType = PregelInputType,\n    OutputType = PregelOutputType,\n    StreamUpdatesType = InputType,\n    StreamValuesType = OutputType,\n    NodeReturnType = unknown,\n    CommandType = CommandInstance,\n    // eslint-disable-next-line @typescript-eslint/no-explicit-any\n    StreamCustom = any\n  >\n  extends PartialRunnable<\n    InputType | CommandType | null,\n    OutputType,\n    PregelOptions<Nodes, Channels, ContextType>\n  >\n  implements PregelInterface<Nodes, Channels, ContextType>\n{\n  /**\n   * Name of the class when serialized\n   * @internal\n   */\n  static lc_name() {\n    return \"LangGraph\";\n  }\n\n  /** @internal Used for type inference */\n  declare \"~InputType\": InputType;\n\n  /** @internal Used for type inference */\n  declare \"~OutputType\": OutputType;\n\n  /** @internal LangChain namespace for serialization necessary because Pregel extends Runnable */\n  lc_namespace = [\"langgraph\", \"pregel\"];\n\n  /** @internal Flag indicating this is a Pregel instance - necessary for serialization */\n  lg_is_pregel = true;\n\n  /** The nodes in the graph, mapping node names to their PregelNode instances */\n  nodes: Nodes;\n\n  /** The channels in the graph, mapping channel names to their BaseChannel or ManagedValueSpec instances */\n  channels: Channels;\n\n  /**\n   * The input channels for the graph. These channels receive the initial input when the graph is invoked.\n   * Can be a single channel key or an array of channel keys.\n   */\n  inputChannels: keyof Channels | Array<keyof Channels>;\n\n  /**\n   * The output channels for the graph. These channels contain the final output when the graph completes.\n   * Can be a single channel key or an array of channel keys.\n   */\n  outputChannels: keyof Channels | Array<keyof Channels>;\n\n  /** Whether to automatically validate the graph structure when it is compiled. Defaults to true. */\n  autoValidate: boolean = true;\n\n  /**\n   * The streaming modes enabled for this graph. Defaults to [\"values\"].\n   * Supported modes:\n   * - \"values\": Streams the full state after each step\n   * - \"updates\": Streams state updates after each step\n   * - \"messages\": Streams messages from within nodes\n   * - \"custom\": Streams custom events from within nodes\n   * - \"debug\": Streams events related to the execution of the graph - useful for tracing & debugging graph execution\n   */\n  streamMode: StreamMode[] = [\"values\"];\n\n  /**\n   * Optional channels to stream. If not specified, all channels will be streamed.\n   * Can be a single channel key or an array of channel keys.\n   */\n  streamChannels?: keyof Channels | Array<keyof Channels>;\n\n  /**\n   * Optional array of node names or \"all\" to interrupt after executing these nodes.\n   * Used for implementing human-in-the-loop workflows.\n   */\n  interruptAfter?: Array<keyof Nodes> | All;\n\n  /**\n   * Optional array of node names or \"all\" to interrupt before executing these nodes.\n   * Used for implementing human-in-the-loop workflows.\n   */\n  interruptBefore?: Array<keyof Nodes> | All;\n\n  /** Optional timeout in milliseconds for the execution of each superstep */\n  stepTimeout?: number;\n\n  /** Whether to enable debug logging. Defaults to false. */\n  debug: boolean = false;\n\n  /**\n   * Optional checkpointer for persisting graph state.\n   * When provided, saves a checkpoint of the graph state at every superstep.\n   * When false or undefined, checkpointing is disabled, and the graph will not be able to save or restore state.\n   */\n  checkpointer?: BaseCheckpointSaver | boolean;\n\n  /** Optional retry policy for handling failures in node execution */\n  retryPolicy?: RetryPolicy;\n\n  /** The default configuration for graph execution, can be overridden on a per-invocation basis */\n  config?: LangGraphRunnableConfig;\n\n  /**\n   * Optional long-term memory store for the graph, allows for persistence & retrieval of data across threads\n   */\n  store?: BaseStore;\n\n  /**\n   * Optional cache for the graph, useful for caching tasks.\n   */\n  cache?: BaseCache;\n\n  /**\n   * Optional interrupt helper function.\n   * @internal\n   */\n  private userInterrupt?: unknown;\n\n  /**\n   * The trigger to node mapping for the graph run.\n   * @internal\n   */\n  private triggerToNodes: Record<string, string[]> = {};\n\n  /**\n   * Constructor for Pregel - meant for internal use only.\n   *\n   * @internal\n   */\n  constructor(fields: PregelParams<Nodes, Channels>) {\n    super(fields);\n\n    let { streamMode } = fields;\n    if (streamMode != null && !Array.isArray(streamMode)) {\n      streamMode = [streamMode];\n    }\n\n    this.nodes = fields.nodes;\n    this.channels = fields.channels;\n\n    if (\n      TASKS in this.channels &&\n      \"lc_graph_name\" in this.channels[TASKS] &&\n      this.channels[TASKS].lc_graph_name !== \"Topic\"\n    ) {\n      throw new Error(\n        `Channel '${TASKS}' is reserved and cannot be used in the graph.`\n      );\n    } else {\n      (this.channels as Record<string, BaseChannel>)[TASKS] =\n        new Topic<SendProtocol>({ accumulate: false });\n    }\n\n    this.autoValidate = fields.autoValidate ?? this.autoValidate;\n    this.streamMode = streamMode ?? this.streamMode;\n    this.inputChannels = fields.inputChannels;\n    this.outputChannels = fields.outputChannels;\n    this.streamChannels = fields.streamChannels ?? this.streamChannels;\n    this.interruptAfter = fields.interruptAfter;\n    this.interruptBefore = fields.interruptBefore;\n    this.stepTimeout = fields.stepTimeout ?? this.stepTimeout;\n    this.debug = fields.debug ?? this.debug;\n    this.checkpointer = fields.checkpointer;\n    this.retryPolicy = fields.retryPolicy;\n    this.config = fields.config;\n    this.store = fields.store;\n    this.cache = fields.cache;\n    this.name = fields.name;\n    this.triggerToNodes = fields.triggerToNodes ?? this.triggerToNodes;\n    this.userInterrupt = fields.userInterrupt;\n\n    if (this.autoValidate) {\n      this.validate();\n    }\n  }\n\n  /**\n   * Creates a new instance of the Pregel graph with updated configuration.\n   * This method follows the immutable pattern - instead of modifying the current instance,\n   * it returns a new instance with the merged configuration.\n   *\n   * @example\n   * ```typescript\n   * // Create a new instance with debug enabled\n   * const debugGraph = graph.withConfig({ debug: true });\n   *\n   * // Create a new instance with a specific thread ID\n   * const threadGraph = graph.withConfig({\n   *   configurable: { thread_id: \"123\" }\n   * });\n   * ```\n   *\n   * @param config - The configuration to merge with the current configuration\n   * @returns A new Pregel instance with the merged configuration\n   */\n  override withConfig(\n    config: Omit<LangGraphRunnableConfig, \"store\" | \"writer\" | \"interrupt\">\n  ): typeof this {\n    const mergedConfig = mergeConfigs(this.config, config);\n    // eslint-disable-next-line @typescript-eslint/no-explicit-any\n    return new (this.constructor as any)({ ...this, config: mergedConfig });\n  }\n\n  /**\n   * Validates the graph structure to ensure it is well-formed.\n   * Checks for:\n   * - No orphaned nodes\n   * - Valid input/output channel configurations\n   * - Valid interrupt configurations\n   *\n   * @returns this - The Pregel instance for method chaining\n   * @throws {GraphValidationError} If the graph structure is invalid\n   */\n  validate(): this {\n    validateGraph<Nodes, Channels>({\n      nodes: this.nodes,\n      channels: this.channels,\n      outputChannels: this.outputChannels,\n      inputChannels: this.inputChannels,\n      streamChannels: this.streamChannels,\n      interruptAfterNodes: this.interruptAfter,\n      interruptBeforeNodes: this.interruptBefore,\n    });\n\n    for (const [name, node] of Object.entries(this.nodes)) {\n      for (const trigger of node.triggers) {\n        this.triggerToNodes[trigger] ??= [];\n        this.triggerToNodes[trigger].push(name);\n      }\n    }\n\n    return this;\n  }\n\n  /**\n   * Gets a list of all channels that should be streamed.\n   * If streamChannels is specified, returns those channels.\n   * Otherwise, returns all channels in the graph.\n   *\n   * @returns Array of channel keys to stream\n   */\n  get streamChannelsList(): Array<keyof Channels> {\n    if (Array.isArray(this.streamChannels)) {\n      return this.streamChannels;\n    } else if (this.streamChannels) {\n      return [this.streamChannels];\n    } else {\n      return Object.keys(this.channels);\n    }\n  }\n\n  /**\n   * Gets the channels to stream in their original format.\n   * If streamChannels is specified, returns it as-is (either single key or array).\n   * Otherwise, returns all channels in the graph as an array.\n   *\n   * @returns Channel keys to stream, either as a single key or array\n   */\n  get streamChannelsAsIs(): keyof Channels | Array<keyof Channels> {\n    if (this.streamChannels) {\n      return this.streamChannels;\n    } else {\n      return Object.keys(this.channels);\n    }\n  }\n\n  /**\n   * Gets a drawable representation of the graph structure.\n   * This is an async version of getGraph() and is the preferred method to use.\n   *\n   * @param config - Configuration for generating the graph visualization\n   * @returns A representation of the graph that can be visualized\n   */\n  async getGraphAsync(config: RunnableConfig) {\n    return this.getGraph(config);\n  }\n\n  /**\n   * Gets all subgraphs within this graph.\n   * A subgraph is a Pregel instance that is nested within a node of this graph.\n   *\n   * @deprecated Use getSubgraphsAsync instead. The async method will become the default in the next minor release.\n   * @param namespace - Optional namespace to filter subgraphs\n   * @param recurse - Whether to recursively get subgraphs of subgraphs\n   * @returns Generator yielding tuples of [name, subgraph]\n   */\n  *getSubgraphs(\n    namespace?: string,\n    recurse?: boolean\n    // eslint-disable-next-line @typescript-eslint/no-explicit-any\n  ): Generator<[string, Pregel<any, any>]> {\n    for (const [name, node] of Object.entries(this.nodes)) {\n      // filter by prefix\n      if (namespace !== undefined) {\n        if (!namespace.startsWith(name)) {\n          continue;\n        }\n      }\n      // find the subgraph if any\n      // eslint-disable-next-line @typescript-eslint/no-explicit-any\n      type SubgraphPregelType = Pregel<any, any> | undefined;\n\n      const candidates = node.subgraphs?.length ? node.subgraphs : [node.bound];\n\n      for (const candidate of candidates) {\n        const graph = findSubgraphPregel(candidate) as SubgraphPregelType;\n\n        if (graph !== undefined) {\n          if (name === namespace) {\n            yield [name, graph];\n            return;\n          }\n\n          if (namespace === undefined) {\n            yield [name, graph];\n          }\n\n          if (recurse) {\n            let newNamespace = namespace;\n            if (namespace !== undefined) {\n              newNamespace = namespace.slice(name.length + 1);\n            }\n            for (const [subgraphName, subgraph] of graph.getSubgraphs(\n              newNamespace,\n              recurse\n            )) {\n              yield [\n                `${name}${CHECKPOINT_NAMESPACE_SEPARATOR}${subgraphName}`,\n                subgraph,\n              ];\n            }\n          }\n        }\n      }\n    }\n  }\n\n  /**\n   * Gets all subgraphs within this graph asynchronously.\n   * A subgraph is a Pregel instance that is nested within a node of this graph.\n   *\n   * @param namespace - Optional namespace to filter subgraphs\n   * @param recurse - Whether to recursively get subgraphs of subgraphs\n   * @returns AsyncGenerator yielding tuples of [name, subgraph]\n   */\n  async *getSubgraphsAsync(\n    namespace?: string,\n    recurse?: boolean\n    // eslint-disable-next-line @typescript-eslint/no-explicit-any\n  ): AsyncGenerator<[string, Pregel<any, any>]> {\n    yield* this.getSubgraphs(namespace, recurse);\n  }\n\n  /**\n   * Prepares a state snapshot from saved checkpoint data.\n   * This is an internal method used by getState and getStateHistory.\n   *\n   * @param config - Configuration for preparing the snapshot\n   * @param saved - Optional saved checkpoint data\n   * @param subgraphCheckpointer - Optional checkpointer for subgraphs\n   * @param applyPendingWrites - Whether to apply pending writes to tasks and then to channels\n   * @returns A snapshot of the graph state\n   * @internal\n   */\n  protected async _prepareStateSnapshot({\n    config,\n    saved,\n    subgraphCheckpointer,\n    applyPendingWrites = false,\n  }: {\n    config: RunnableConfig;\n    saved?: CheckpointTuple;\n    subgraphCheckpointer?: BaseCheckpointSaver;\n    applyPendingWrites?: boolean;\n  }): Promise<StateSnapshot> {\n    if (saved === undefined) {\n      return {\n        values: {},\n        next: [],\n        config,\n        tasks: [],\n      };\n    }\n\n    // Create all channels\n    const channels = emptyChannels(\n      this.channels as Record<string, BaseChannel>,\n      saved.checkpoint\n    );\n\n    // Apply null writes first (from NULL_TASK_ID)\n    if (saved.pendingWrites?.length) {\n      const nullWrites = saved.pendingWrites\n        .filter(([taskId, _]) => taskId === NULL_TASK_ID)\n        .map(\n          ([_, channel, value]) => [String(channel), value] as [string, unknown]\n        );\n\n      if (nullWrites.length > 0) {\n        _applyWrites(\n          saved.checkpoint,\n          channels,\n          [\n            {\n              name: INPUT,\n              writes: nullWrites as PendingWrite[],\n              triggers: [],\n            },\n          ],\n          undefined,\n          this.triggerToNodes\n        );\n      }\n    }\n\n    // Prepare next tasks\n    const nextTasks = Object.values(\n      _prepareNextTasks(\n        saved.checkpoint,\n        saved.pendingWrites,\n        this.nodes,\n        channels,\n        saved.config,\n        true,\n        { step: (saved.metadata?.step ?? -1) + 1, store: this.store }\n      )\n    );\n\n    // Find subgraphs\n    const subgraphs = await gatherIterator(this.getSubgraphsAsync());\n    const parentNamespace = saved.config.configurable?.checkpoint_ns ?? \"\";\n    const taskStates: Record<string, RunnableConfig | StateSnapshot> = {};\n\n    // Prepare task states for subgraphs\n    for (const task of nextTasks) {\n      const matchingSubgraph = subgraphs.find(([name]) => name === task.name);\n      if (!matchingSubgraph) {\n        continue;\n      }\n      // assemble checkpoint_ns for this task\n      let taskNs = `${String(task.name)}${CHECKPOINT_NAMESPACE_END}${task.id}`;\n      if (parentNamespace) {\n        taskNs = `${parentNamespace}${CHECKPOINT_NAMESPACE_SEPARATOR}${taskNs}`;\n      }\n      if (subgraphCheckpointer === undefined) {\n        // set config as signal that subgraph checkpoints exist\n        const config: RunnableConfig = {\n          configurable: {\n            thread_id: saved.config.configurable?.thread_id,\n            checkpoint_ns: taskNs,\n          },\n        };\n        taskStates[task.id] = config;\n      } else {\n        // get the state of the subgraph\n        const subgraphConfig: RunnableConfig = {\n          configurable: {\n            [CONFIG_KEY_CHECKPOINTER]: subgraphCheckpointer,\n            thread_id: saved.config.configurable?.thread_id,\n            checkpoint_ns: taskNs,\n          },\n        };\n        const pregel = matchingSubgraph[1];\n        taskStates[task.id] = await pregel.getState(subgraphConfig, {\n          subgraphs: true,\n        });\n      }\n    }\n\n    // Apply pending writes to tasks and then to channels if applyPendingWrites is true\n    if (applyPendingWrites && saved.pendingWrites?.length) {\n      // Map task IDs to task objects for easy lookup\n      const nextTaskById = Object.fromEntries(\n        nextTasks.map((task) => [task.id, task])\n      );\n\n      // Apply pending writes to the appropriate tasks\n      for (const [taskId, channel, value] of saved.pendingWrites) {\n        // Skip special channels and tasks not in nextTasks\n        if ([ERROR, INTERRUPT, SCHEDULED].includes(channel)) {\n          continue;\n        }\n        if (!(taskId in nextTaskById)) {\n          continue;\n        }\n        // Add the write to the task\n        nextTaskById[taskId].writes.push([String(channel), value]);\n      }\n\n      // Apply writes from tasks that have writes\n      const tasksWithWrites = nextTasks.filter(\n        (task) => task.writes.length > 0\n      );\n      if (tasksWithWrites.length > 0) {\n        _applyWrites(\n          saved.checkpoint,\n          channels,\n          tasksWithWrites as unknown as WritesProtocol[],\n          undefined,\n          this.triggerToNodes\n        );\n      }\n    }\n\n    // Preserve thread_id from the config in metadata\n    let metadata = saved?.metadata;\n    if (metadata && saved?.config?.configurable?.thread_id) {\n      metadata = {\n        ...metadata,\n        thread_id: saved.config.configurable.thread_id as string,\n      } as CheckpointMetadata;\n    }\n\n    // Filter next tasks - only include tasks without writes\n    const nextList = nextTasks\n      .filter((task) => task.writes.length === 0)\n      .map((task) => task.name as string);\n\n    // assemble the state snapshot\n    return {\n      values: readChannels(\n        channels,\n        this.streamChannelsAsIs as string | string[]\n      ),\n      next: nextList,\n      tasks: tasksWithWrites(\n        nextTasks,\n        saved?.pendingWrites ?? [],\n        taskStates,\n        this.streamChannelsAsIs\n      ),\n      metadata,\n      config: patchCheckpointMap(saved.config, saved.metadata),\n      createdAt: saved.checkpoint.ts,\n      parentConfig: saved.parentConfig,\n    };\n  }\n\n  /**\n   * Gets the current state of the graph.\n   * Requires a checkpointer to be configured.\n   *\n   * @param config - Configuration for retrieving the state\n   * @param options - Additional options\n   * @returns A snapshot of the current graph state\n   * @throws {GraphValueError} If no checkpointer is configured\n   */\n  async getState(\n    config: RunnableConfig,\n    options?: GetStateOptions\n  ): Promise<StateSnapshot> {\n    const checkpointer =\n      config.configurable?.[CONFIG_KEY_CHECKPOINTER] ?? this.checkpointer;\n    if (!checkpointer) {\n      throw new GraphValueError(\"No checkpointer set\", {\n        lc_error_code: \"MISSING_CHECKPOINTER\",\n      });\n    }\n\n    const checkpointNamespace: string =\n      config.configurable?.checkpoint_ns ?? \"\";\n    if (\n      checkpointNamespace !== \"\" &&\n      config.configurable?.[CONFIG_KEY_CHECKPOINTER] === undefined\n    ) {\n      // remove task_ids from checkpoint_ns\n      const recastNamespace = recastCheckpointNamespace(checkpointNamespace);\n      for await (const [name, subgraph] of this.getSubgraphsAsync(\n        recastNamespace,\n        true\n      )) {\n        if (name === recastNamespace) {\n          return await subgraph.getState(\n            patchConfigurable(config, {\n              [CONFIG_KEY_CHECKPOINTER]: checkpointer,\n            }),\n            { subgraphs: options?.subgraphs }\n          );\n        }\n      }\n      throw new Error(\n        `Subgraph with namespace \"${recastNamespace}\" not found.`\n      );\n    }\n\n    const mergedConfig = mergeConfigs(this.config, config);\n    const saved = await checkpointer.getTuple(config);\n    const snapshot = await this._prepareStateSnapshot({\n      config: mergedConfig,\n      saved,\n      subgraphCheckpointer: options?.subgraphs ? checkpointer : undefined,\n      applyPendingWrites: !config.configurable?.checkpoint_id,\n    });\n    return snapshot;\n  }\n\n  /**\n   * Gets the history of graph states.\n   * Requires a checkpointer to be configured.\n   * Useful for:\n   * - Debugging execution history\n   * - Implementing time travel\n   * - Analyzing graph behavior\n   *\n   * @param config - Configuration for retrieving the history\n   * @param options - Options for filtering the history\n   * @returns An async iterator of state snapshots\n   * @throws {Error} If no checkpointer is configured\n   */\n  async *getStateHistory(\n    config: RunnableConfig,\n    options?: CheckpointListOptions\n  ): AsyncIterableIterator<StateSnapshot> {\n    const checkpointer: BaseCheckpointSaver =\n      config.configurable?.[CONFIG_KEY_CHECKPOINTER] ?? this.checkpointer;\n    if (!checkpointer) {\n      throw new GraphValueError(\"No checkpointer set\", {\n        lc_error_code: \"MISSING_CHECKPOINTER\",\n      });\n    }\n\n    const checkpointNamespace: string =\n      config.configurable?.checkpoint_ns ?? \"\";\n    if (\n      checkpointNamespace !== \"\" &&\n      config.configurable?.[CONFIG_KEY_CHECKPOINTER] === undefined\n    ) {\n      const recastNamespace = recastCheckpointNamespace(checkpointNamespace);\n\n      // find the subgraph with the matching name\n      for await (const [name, pregel] of this.getSubgraphsAsync(\n        recastNamespace,\n        true\n      )) {\n        if (name === recastNamespace) {\n          yield* pregel.getStateHistory(\n            patchConfigurable(config, {\n              [CONFIG_KEY_CHECKPOINTER]: checkpointer,\n            }),\n            options\n          );\n          return;\n        }\n      }\n      throw new Error(\n        `Subgraph with namespace \"${recastNamespace}\" not found.`\n      );\n    }\n\n    const mergedConfig = mergeConfigs(this.config, config, {\n      configurable: { checkpoint_ns: checkpointNamespace },\n    });\n\n    for await (const checkpointTuple of checkpointer.list(\n      mergedConfig,\n      options\n    )) {\n      yield this._prepareStateSnapshot({\n        config: checkpointTuple.config,\n        saved: checkpointTuple,\n      });\n    }\n  }\n\n  /**\n   * Apply updates to the graph state in bulk.\n   * Requires a checkpointer to be configured.\n   *\n   * This method is useful for recreating a thread\n   * from a list of updates, especially if a checkpoint\n   * is created as a result of multiple tasks.\n   *\n   * @internal The API might change in the future.\n   *\n   * @param startConfig - Configuration for the update\n   * @param updates - The list of updates to apply to graph state\n   * @returns Updated configuration\n   * @throws {GraphValueError} If no checkpointer is configured\n   * @throws {InvalidUpdateError} If the update cannot be attributed to a node or an update can be only applied in sequence.\n   */\n  async bulkUpdateState(\n    startConfig: LangGraphRunnableConfig,\n    supersteps: Array<{\n      updates: Array<{\n        values?: Record<string, unknown> | unknown;\n        asNode?: keyof Nodes | string;\n      }>;\n    }>\n  ): Promise<RunnableConfig> {\n    const checkpointer: BaseCheckpointSaver | undefined =\n      startConfig.configurable?.[CONFIG_KEY_CHECKPOINTER] ?? this.checkpointer;\n    if (!checkpointer) {\n      throw new GraphValueError(\"No checkpointer set\", {\n        lc_error_code: \"MISSING_CHECKPOINTER\",\n      });\n    }\n    if (supersteps.length === 0) {\n      throw new Error(\"No supersteps provided\");\n    }\n\n    if (supersteps.some((s) => s.updates.length === 0)) {\n      throw new Error(\"No updates provided\");\n    }\n\n    // delegate to subgraph\n    const checkpointNamespace: string =\n      startConfig.configurable?.checkpoint_ns ?? \"\";\n    if (\n      checkpointNamespace !== \"\" &&\n      startConfig.configurable?.[CONFIG_KEY_CHECKPOINTER] === undefined\n    ) {\n      // remove task_ids from checkpoint_ns\n      const recastNamespace = recastCheckpointNamespace(checkpointNamespace);\n      // find the subgraph with the matching name\n      // eslint-disable-next-line no-unreachable-loop\n      for await (const [, pregel] of this.getSubgraphsAsync(\n        recastNamespace,\n        true\n      )) {\n        return await pregel.bulkUpdateState(\n          patchConfigurable(startConfig, {\n            [CONFIG_KEY_CHECKPOINTER]: checkpointer,\n          }),\n          supersteps\n        );\n      }\n      throw new Error(`Subgraph \"${recastNamespace}\" not found`);\n    }\n\n    const updateSuperStep = async (\n      inputConfig: LangGraphRunnableConfig,\n      updates: {\n        values?: Record<string, unknown> | unknown;\n        asNode?: keyof Nodes | string;\n        taskId?: string;\n      }[]\n    ) => {\n      // get last checkpoint\n      const config = this.config\n        ? mergeConfigs(this.config, inputConfig)\n        : inputConfig;\n      const saved = await checkpointer.getTuple(config);\n      const checkpoint =\n        saved !== undefined\n          ? copyCheckpoint(saved.checkpoint)\n          : emptyCheckpoint();\n      const checkpointPreviousVersions = {\n        ...saved?.checkpoint.channel_versions,\n      };\n      const step = saved?.metadata?.step ?? -1;\n\n      // merge configurable fields with previous checkpoint config\n      let checkpointConfig = patchConfigurable(config, {\n        checkpoint_ns: config.configurable?.checkpoint_ns ?? \"\",\n      });\n      let checkpointMetadata = config.metadata ?? {};\n      if (saved?.config.configurable) {\n        checkpointConfig = patchConfigurable(config, saved.config.configurable);\n        checkpointMetadata = {\n          ...saved.metadata,\n          ...checkpointMetadata,\n        };\n      }\n\n      // Find last node that updated the state, if not provided\n      const { values, asNode } = updates[0];\n      if (values == null && asNode === undefined) {\n        if (updates.length > 1) {\n          throw new InvalidUpdateError(\n            `Cannot create empty checkpoint with multiple updates`\n          );\n        }\n\n        const nextConfig = await checkpointer.put(\n          checkpointConfig,\n          createCheckpoint(checkpoint, undefined, step),\n          {\n            source: \"update\",\n            step: step + 1,\n            parents: saved?.metadata?.parents ?? {},\n          },\n          {}\n        );\n        return patchCheckpointMap(\n          nextConfig,\n          saved ? saved.metadata : undefined\n        );\n      }\n\n      // update channels\n      const channels = emptyChannels(\n        this.channels as Record<string, BaseChannel>,\n        checkpoint\n      );\n\n      if (values === null && asNode === END) {\n        if (updates.length > 1) {\n          throw new InvalidUpdateError(\n            `Cannot apply multiple updates when clearing state`\n          );\n        }\n\n        if (saved) {\n          // tasks for this checkpoint\n          const nextTasks = _prepareNextTasks(\n            checkpoint,\n            saved.pendingWrites || [],\n            this.nodes,\n            channels,\n            saved.config,\n            true,\n            {\n              step: (saved.metadata?.step ?? -1) + 1,\n              checkpointer,\n              store: this.store,\n            }\n          );\n\n          // apply null writes\n          const nullWrites = (saved.pendingWrites || [])\n            .filter((w) => w[0] === NULL_TASK_ID)\n            .map((w) => w.slice(1)) as PendingWrite<string>[];\n          if (nullWrites.length > 0) {\n            _applyWrites(\n              checkpoint,\n              channels,\n              [\n                {\n                  name: INPUT,\n                  writes: nullWrites,\n                  triggers: [],\n                },\n              ],\n              checkpointer.getNextVersion.bind(checkpointer),\n              this.triggerToNodes\n            );\n          }\n          // apply writes from tasks that already ran\n          for (const [taskId, k, v] of saved.pendingWrites || []) {\n            if ([ERROR, INTERRUPT, SCHEDULED].includes(k)) {\n              continue;\n            }\n            if (!(taskId in nextTasks)) {\n              continue;\n            }\n            nextTasks[taskId].writes.push([k, v]);\n          }\n          // clear all current tasks\n          _applyWrites(\n            checkpoint,\n            channels,\n            Object.values(nextTasks) as WritesProtocol<string>[],\n            checkpointer.getNextVersion.bind(checkpointer),\n            this.triggerToNodes\n          );\n        }\n        // save checkpoint\n        const nextConfig = await checkpointer.put(\n          checkpointConfig,\n          createCheckpoint(checkpoint, channels, step),\n          {\n            ...checkpointMetadata,\n            source: \"update\",\n            step: step + 1,\n            parents: saved?.metadata?.parents ?? {},\n          },\n          getNewChannelVersions(\n            checkpointPreviousVersions,\n            checkpoint.channel_versions\n          )\n        );\n        return patchCheckpointMap(\n          nextConfig,\n          saved ? saved.metadata : undefined\n        );\n      }\n\n      if (asNode === COPY) {\n        if (updates.length > 1) {\n          throw new InvalidUpdateError(\n            `Cannot copy checkpoint with multiple updates`\n          );\n        }\n\n        if (saved == null) {\n          throw new InvalidUpdateError(`Cannot copy a non-existent checkpoint`);\n        }\n\n        const isCopyWithUpdates = (\n          values: unknown\n        ): values is [values: unknown, asNode: string][] => {\n          if (!Array.isArray(values)) return false;\n          if (values.length === 0) return false;\n          return values.every((v) => Array.isArray(v) && v.length === 2);\n        };\n\n        const nextCheckpoint = createCheckpoint(checkpoint, undefined, step);\n        const nextConfig = await checkpointer.put(\n          saved.parentConfig ??\n            patchConfigurable(saved.config, { checkpoint_id: undefined }),\n          nextCheckpoint,\n          {\n            source: \"fork\",\n            step: step + 1,\n            parents: saved.metadata?.parents ?? {},\n          },\n          {}\n        );\n\n        // We want to both clone a checkpoint and update state in one go.\n        // Reuse the same task ID if possible.\n        if (isCopyWithUpdates(values)) {\n          // figure out the task IDs for the next update checkpoint\n          const nextTasks = _prepareNextTasks(\n            nextCheckpoint,\n            saved.pendingWrites,\n            this.nodes,\n            channels,\n            nextConfig,\n            false,\n            { step: step + 2 }\n          );\n\n          const tasksGroupBy = Object.values(nextTasks).reduce<\n            Record<string, { id: string }[]>\n          >((acc, { name, id }) => {\n            acc[name] ??= [];\n            acc[name].push({ id });\n            return acc;\n          }, {});\n\n          const userGroupBy = values.reduce<\n            Record<\n              string,\n              { values: unknown; asNode: string; taskId?: string }[]\n            >\n          >((acc, item) => {\n            const [values, asNode] = item;\n            acc[asNode] ??= [];\n\n            const targetIdx = acc[asNode].length;\n            const taskId = tasksGroupBy[asNode]?.[targetIdx]?.id;\n            acc[asNode].push({ values, asNode, taskId });\n\n            return acc;\n          }, {});\n\n          return updateSuperStep(\n            patchCheckpointMap(nextConfig, saved.metadata),\n            Object.values(userGroupBy).flat()\n          );\n        }\n\n        return patchCheckpointMap(nextConfig, saved.metadata);\n      }\n\n      if (asNode === INPUT) {\n        if (updates.length > 1) {\n          throw new InvalidUpdateError(\n            `Cannot apply multiple updates when updating as input`\n          );\n        }\n\n        const inputWrites = await gatherIterator(\n          mapInput(this.inputChannels, values)\n        );\n        if (inputWrites.length === 0) {\n          throw new InvalidUpdateError(\n            `Received no input writes for ${JSON.stringify(\n              this.inputChannels,\n              null,\n              2\n            )}`\n          );\n        }\n\n        // apply to checkpoint\n        _applyWrites(\n          checkpoint,\n          channels,\n          [\n            {\n              name: INPUT,\n              writes: inputWrites as PendingWrite[],\n              triggers: [],\n            },\n          ],\n          checkpointer.getNextVersion.bind(this.checkpointer),\n          this.triggerToNodes\n        );\n\n        // apply input write to channels\n        const nextStep =\n          saved?.metadata?.step != null ? saved.metadata.step + 1 : -1;\n        const nextConfig = await checkpointer.put(\n          checkpointConfig,\n          createCheckpoint(checkpoint, channels, nextStep),\n          {\n            source: \"input\",\n            step: nextStep,\n            parents: saved?.metadata?.parents ?? {},\n          },\n          getNewChannelVersions(\n            checkpointPreviousVersions,\n            checkpoint.channel_versions\n          )\n        );\n\n        // Store the writes\n        await checkpointer.putWrites(\n          nextConfig,\n          inputWrites as PendingWrite[],\n          uuid5(INPUT, checkpoint.id)\n        );\n\n        return patchCheckpointMap(\n          nextConfig,\n          saved ? saved.metadata : undefined\n        );\n      }\n\n      // apply pending writes, if not on specific checkpoint\n      if (\n        config.configurable?.checkpoint_id === undefined &&\n        saved?.pendingWrites !== undefined &&\n        saved.pendingWrites.length > 0\n      ) {\n        // tasks for this checkpoint\n        const nextTasks = _prepareNextTasks(\n          checkpoint,\n          saved.pendingWrites,\n          this.nodes,\n          channels,\n          saved.config,\n          true,\n          {\n            store: this.store,\n            // eslint-disable-next-line @typescript-eslint/no-explicit-any\n            checkpointer: this.checkpointer as any,\n            step: (saved.metadata?.step ?? -1) + 1,\n          }\n        );\n        // apply null writes\n        const nullWrites = (saved.pendingWrites ?? [])\n          .filter((w) => w[0] === NULL_TASK_ID)\n          .map((w) => w.slice(1)) as PendingWrite<string>[];\n        if (nullWrites.length > 0) {\n          _applyWrites(\n            saved.checkpoint,\n            channels,\n            [{ name: INPUT, writes: nullWrites, triggers: [] }],\n            undefined,\n            this.triggerToNodes\n          );\n        }\n        // apply writes\n        for (const [tid, k, v] of saved.pendingWrites) {\n          if (\n            [ERROR, INTERRUPT, SCHEDULED].includes(k) ||\n            nextTasks[tid] === undefined\n          ) {\n            continue;\n          }\n          nextTasks[tid].writes.push([k, v]);\n        }\n        const tasks = Object.values(nextTasks).filter((task) => {\n          return task.writes.length > 0;\n        });\n        if (tasks.length > 0) {\n          _applyWrites(\n            checkpoint,\n            channels,\n            tasks as WritesProtocol[],\n            undefined,\n            this.triggerToNodes\n          );\n        }\n      }\n      const nonNullVersion = Object.values(checkpoint.versions_seen)\n        .map((seenVersions) => {\n          return Object.values(seenVersions);\n        })\n        .flat()\n        .find((v) => !!v);\n\n      const validUpdates: Array<{\n        values: Record<string, unknown> | unknown;\n        asNode: keyof