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https://github.com/Abdulazizzn/n8n-enterprise-unlocked.git
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feat: AI Workflow Builder agent (no-changelog) (#17423)
Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>
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oleg
@@ -0,0 +1,289 @@
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import type { BaseChatModel } from '@langchain/core/language_models/chat_models';
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import type { AIMessage, ToolMessage } from '@langchain/core/messages';
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import { HumanMessage, RemoveMessage } from '@langchain/core/messages';
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import type { LangChainTracer } from '@langchain/core/tracers/tracer_langchain';
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import { StateGraph, MemorySaver, END } from '@langchain/langgraph';
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import type { Logger } from '@n8n/backend-common';
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import type {
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INodeTypeDescription,
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IRunExecutionData,
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IWorkflowBase,
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NodeExecutionSchema,
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} from 'n8n-workflow';
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import { conversationCompactChain } from './chains/conversation-compact';
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import { LLMServiceError } from './errors';
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import { createAddNodeTool } from './tools/add-node.tool';
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import { createConnectNodesTool } from './tools/connect-nodes.tool';
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import { createNodeDetailsTool } from './tools/node-details.tool';
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import { createNodeSearchTool } from './tools/node-search.tool';
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import { mainAgentPrompt } from './tools/prompts/main-agent.prompt';
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import { createRemoveNodeTool } from './tools/remove-node.tool';
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import { createUpdateNodeParametersTool } from './tools/update-node-parameters.tool';
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import type { SimpleWorkflow } from './types/workflow';
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import { processOperations } from './utils/operations-processor';
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import { createStreamProcessor, formatMessages } from './utils/stream-processor';
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import { executeToolsInParallel } from './utils/tool-executor';
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import { WorkflowState } from './workflow-state';
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export interface WorkflowBuilderAgentConfig {
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parsedNodeTypes: INodeTypeDescription[];
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llmSimpleTask: BaseChatModel;
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llmComplexTask: BaseChatModel;
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logger?: Logger;
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checkpointer?: MemorySaver;
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tracer?: LangChainTracer;
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}
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export interface ChatPayload {
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message: string;
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workflowContext?: {
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executionSchema?: NodeExecutionSchema[];
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currentWorkflow?: Partial<IWorkflowBase>;
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executionData?: IRunExecutionData['resultData'];
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};
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}
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export class WorkflowBuilderAgent {
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private checkpointer: MemorySaver;
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private parsedNodeTypes: INodeTypeDescription[];
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private llmSimpleTask: BaseChatModel;
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private llmComplexTask: BaseChatModel;
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private logger?: Logger;
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private tracer?: LangChainTracer;
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constructor(config: WorkflowBuilderAgentConfig) {
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this.parsedNodeTypes = config.parsedNodeTypes;
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this.llmSimpleTask = config.llmSimpleTask;
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this.llmComplexTask = config.llmComplexTask;
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this.logger = config.logger;
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this.checkpointer = config.checkpointer ?? new MemorySaver();
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this.tracer = config.tracer;
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}
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private createWorkflow() {
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const tools = [
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createNodeSearchTool(this.parsedNodeTypes),
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createNodeDetailsTool(this.parsedNodeTypes),
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createAddNodeTool(this.parsedNodeTypes),
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createConnectNodesTool(this.parsedNodeTypes, this.logger),
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createRemoveNodeTool(this.logger),
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createUpdateNodeParametersTool(this.parsedNodeTypes, this.llmComplexTask, this.logger),
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];
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// Create a map for quick tool lookup
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const toolMap = new Map(tools.map((tool) => [tool.name, tool]));
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const callModel = async (state: typeof WorkflowState.State) => {
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if (!this.llmSimpleTask) {
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throw new LLMServiceError('LLM not setup');
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}
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if (typeof this.llmSimpleTask.bindTools !== 'function') {
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throw new LLMServiceError('LLM does not support tools', {
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llmModel: this.llmSimpleTask._llmType(),
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});
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}
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const prompt = await mainAgentPrompt.invoke({
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...state,
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executionData: state.workflowContext?.executionData ?? {},
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executionSchema: state.workflowContext?.executionSchema ?? [],
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});
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const response = await this.llmSimpleTask.bindTools(tools).invoke(prompt);
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return { messages: [response] };
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};
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const shouldModifyState = ({ messages }: typeof WorkflowState.State) => {
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const lastMessage = messages[messages.length - 1] as HumanMessage;
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if (lastMessage.content === '/compact') {
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return 'compact_messages';
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}
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if (lastMessage.content === '/clear') {
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return 'delete_messages';
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}
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return 'agent';
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};
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const shouldContinue = ({ messages }: typeof WorkflowState.State) => {
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const lastMessage = messages[messages.length - 1] as AIMessage;
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if (lastMessage.tool_calls?.length) {
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return 'tools';
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}
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return END;
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};
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const customToolExecutor = async (state: typeof WorkflowState.State) => {
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return await executeToolsInParallel({ state, toolMap });
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};
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function deleteMessages(state: typeof WorkflowState.State) {
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const messages = state.messages;
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const stateUpdate: Partial<typeof WorkflowState.State> = {
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workflowOperations: null,
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workflowContext: {},
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messages: messages.map((m) => new RemoveMessage({ id: m.id! })) ?? [],
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workflowJSON: {
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nodes: [],
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connections: {},
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},
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};
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return stateUpdate;
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}
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const compactSession = async (state: typeof WorkflowState.State) => {
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if (!this.llmSimpleTask) {
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throw new LLMServiceError('LLM not setup');
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}
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const messages = state.messages;
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const compactedMessages = await conversationCompactChain(this.llmSimpleTask, messages);
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return {
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messages: [
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...messages.map((m) => new RemoveMessage({ id: m.id! })),
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...compactedMessages.newMessages,
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],
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};
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};
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const workflow = new StateGraph(WorkflowState)
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.addNode('agent', callModel)
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.addNode('tools', customToolExecutor)
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.addNode('process_operations', processOperations)
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.addNode('delete_messages', deleteMessages)
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.addNode('compact_messages', compactSession)
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.addConditionalEdges('__start__', shouldModifyState)
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.addEdge('tools', 'process_operations')
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.addEdge('process_operations', 'agent')
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.addEdge('delete_messages', END)
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.addEdge('compact_messages', END)
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.addConditionalEdges('agent', shouldContinue);
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return workflow;
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}
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async getState(workflowId: string, userId?: string) {
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const workflow = this.createWorkflow();
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const agent = workflow.compile({ checkpointer: this.checkpointer });
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return await agent.getState({
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configurable: { thread_id: `workflow-${workflowId}-user-${userId ?? new Date().getTime()}` },
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});
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}
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static generateThreadId(workflowId?: string, userId?: string) {
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return workflowId
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? `workflow-${workflowId}-user-${userId ?? new Date().getTime()}`
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: crypto.randomUUID();
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}
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async *chat(payload: ChatPayload, userId?: string) {
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const agent = this.createWorkflow().compile({ checkpointer: this.checkpointer });
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const workflowId = payload.workflowContext?.currentWorkflow?.id;
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// Generate thread ID from workflowId and userId
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// This ensures one session per workflow per user
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const threadId = WorkflowBuilderAgent.generateThreadId(workflowId, userId);
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// Configure thread for checkpointing
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const threadConfig = {
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configurable: {
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thread_id: threadId,
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},
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};
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// Check if this is a subsequent message
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// If so, update the workflowJSON with the current editor state
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const existingCheckpoint = await this.checkpointer.getTuple(threadConfig);
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let stream;
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if (!existingCheckpoint?.checkpoint) {
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// First message - use initial state
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const initialState: typeof WorkflowState.State = {
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messages: [new HumanMessage({ content: payload.message })],
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workflowJSON: (payload.workflowContext?.currentWorkflow as SimpleWorkflow) ?? {
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nodes: [],
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connections: {},
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},
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workflowOperations: [],
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workflowContext: payload.workflowContext,
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};
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stream = await agent.stream(initialState, {
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...threadConfig,
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streamMode: ['updates', 'custom'],
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recursionLimit: 30,
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callbacks: this.tracer ? [this.tracer] : undefined,
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});
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} else {
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// Subsequent message - update the state with current workflow
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const stateUpdate: Partial<typeof WorkflowState.State> = {
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messages: [new HumanMessage({ content: payload.message })],
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workflowOperations: [], // Clear any pending operations from previous message
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workflowContext: payload.workflowContext,
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workflowJSON: { nodes: [], connections: {} }, // Default to empty workflow
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};
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if (payload.workflowContext?.currentWorkflow) {
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stateUpdate.workflowJSON = payload.workflowContext?.currentWorkflow as SimpleWorkflow;
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}
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// Stream with just the new message
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stream = await agent.stream(stateUpdate, {
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...threadConfig,
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streamMode: ['updates', 'custom'],
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recursionLimit: 80,
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callbacks: this.tracer ? [this.tracer] : undefined,
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});
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}
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// Use the stream processor utility to handle chunk processing
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const streamProcessor = createStreamProcessor(stream);
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for await (const output of streamProcessor) {
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yield output;
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}
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}
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async getSessions(workflowId: string | undefined, userId?: string) {
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// For now, we'll return the current session if we have a workflowId
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// MemorySaver doesn't expose a way to list all threads, so we'll need to
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// track this differently if we want to list all sessions
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const sessions = [];
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if (workflowId) {
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const threadId = WorkflowBuilderAgent.generateThreadId(workflowId, userId);
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const threadConfig = {
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configurable: {
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thread_id: threadId,
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},
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};
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try {
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// Try to get the checkpoint for this thread
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const checkpoint = await this.checkpointer.getTuple(threadConfig);
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if (checkpoint?.checkpoint) {
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const messages =
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(checkpoint.checkpoint.channel_values?.messages as Array<
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AIMessage | HumanMessage | ToolMessage
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>) ?? [];
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sessions.push({
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sessionId: threadId,
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messages: formatMessages(messages),
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lastUpdated: checkpoint.checkpoint.ts,
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});
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}
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} catch (error) {
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// Thread doesn't exist yet
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this.logger?.debug('No session found for workflow:', { workflowId, error });
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}
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}
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return { sessions };
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}
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}
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