Feature: Add access to chat history and other useful variables in post-processing (#5511)

* access chat history and other useful variables in post-processing

* cloning data to prevent mutations in post-processing

* Enhance post-processing capabilities by adding support for additional variables and improving the UI for available variables display. Update CustomFunction implementations to utilize post-processing options consistently across components.

---------

Co-authored-by: Henry <hzj94@hotmail.com>

packages/server/src/utils/buildAgentflow.ts

@@ -2122,7 +2122,62 @@ export const executeAgentFlow = async ({
 
     // check if last agentFlowExecutedData.data.output contains the key "content"
     const lastNodeOutput = agentFlowExecutedData[agentFlowExecutedData.length - 1].data?.output as ICommonObject | undefined
-    const content = (lastNodeOutput?.content as string) ?? ' '
+    let content = (lastNodeOutput?.content as string) ?? ' '
+
+    /* Check for post-processing settings */
+    let chatflowConfig: ICommonObject = {}
+    try {
+        if (chatflow.chatbotConfig) {
+            chatflowConfig = typeof chatflow.chatbotConfig === 'string' ? JSON.parse(chatflow.chatbotConfig) : chatflow.chatbotConfig
+        }
+    } catch (e) {
+        logger.error('[server]: Error parsing chatflow config:', e)
+    }
+
+    if (chatflowConfig?.postProcessing?.enabled === true && content) {
+        try {
+            const postProcessingFunction = JSON.parse(chatflowConfig?.postProcessing?.customFunction)
+            const nodeInstanceFilePath = componentNodes['customFunctionAgentflow'].filePath as string
+            const nodeModule = await import(nodeInstanceFilePath)
+            //set the outputs.output to EndingNode to prevent json escaping of content...
+            const nodeData = {
+                inputs: { customFunctionJavascriptFunction: postProcessingFunction }
+            }
+            const runtimeChatHistory = agentflowRuntime.chatHistory || []
+            const chatHistory = [...pastChatHistory, ...runtimeChatHistory]
+            const options: ICommonObject = {
+                chatflowid: chatflow.id,
+                sessionId,
+                chatId,
+                input: question || form,
+                postProcessing: {
+                    rawOutput: content,
+                    chatHistory: cloneDeep(chatHistory),
+                    sourceDocuments: lastNodeOutput?.sourceDocuments ? cloneDeep(lastNodeOutput.sourceDocuments) : undefined,
+                    usedTools: lastNodeOutput?.usedTools ? cloneDeep(lastNodeOutput.usedTools) : undefined,
+                    artifacts: lastNodeOutput?.artifacts ? cloneDeep(lastNodeOutput.artifacts) : undefined,
+                    fileAnnotations: lastNodeOutput?.fileAnnotations ? cloneDeep(lastNodeOutput.fileAnnotations) : undefined
+                },
+                appDataSource,
+                databaseEntities,
+                workspaceId,
+                orgId,
+                logger
+            }
+            const customFuncNodeInstance = new nodeModule.nodeClass()
+            const customFunctionResponse = await customFuncNodeInstance.run(nodeData, question || form, options)
+            const moderatedResponse = customFunctionResponse.output.content
+            if (typeof moderatedResponse === 'string') {
+                content = moderatedResponse
+            } else if (typeof moderatedResponse === 'object') {
+                content = '```json\n' + JSON.stringify(moderatedResponse, null, 2) + '\n```'
+            } else {
+                content = moderatedResponse
+            }
+        } catch (e) {
+            logger.error('[server]: Post Processing Error:', e)
+        }
+    }
 
     // remove credentialId from agentFlowExecutedData
     agentFlowExecutedData = agentFlowExecutedData.map((data) => _removeCredentialId(data))

packages/server/src/utils/buildChatflow.ts

@@ -2,7 +2,7 @@ import { Request } from 'express'
 import * as path from 'path'
 import { DataSource } from 'typeorm'
 import { v4 as uuidv4 } from 'uuid'
-import { omit } from 'lodash'
+import { omit, cloneDeep } from 'lodash'
 import {
     IFileUpload,
     convertSpeechToText,
@@ -817,7 +817,14 @@ export const executeFlow = async ({
                         sessionId,
                         chatId,
                         input: question,
-                        rawOutput: resultText,
+                        postProcessing: {
+                            rawOutput: resultText,
+                            chatHistory: cloneDeep(chatHistory),
+                            sourceDocuments: result?.sourceDocuments ? cloneDeep(result.sourceDocuments) : undefined,
+                            usedTools: result?.usedTools ? cloneDeep(result.usedTools) : undefined,
+                            artifacts: result?.artifacts ? cloneDeep(result.artifacts) : undefined,
+                            fileAnnotations: result?.fileAnnotations ? cloneDeep(result.fileAnnotations) : undefined
+                        },
                         appDataSource,
                         databaseEntities,
                         workspaceId,