feat: Add options to filter conversation history messages used in sequential LLM and Agent nodes (#3653)

* feat: Add option to disable conversation history

- Add new `disableConversationHistory` boolean parameter in LLMNodes.ts and Agent.ts to optionally skip including conversation history in prompts
- Fix potential error in Agent.ts when messages array is empty by adding null safety checks
- Improve memory efficiency by allowing stateless interactions when history isn't needed

* feat: add conversation history filtering options

Replace the disable conversation history feature with a more flexible filtering system that allows selecting:
- User question only
- Last message only
- All messages (default)
- No messages

This provides more granular control over conversation context management.

* chore: break lines

* chore: removed ending semi columns

* chore: fix eslint errors

* fix(sequentialagents): improve conversation history filtering logic

- Remove unnecessary state.messages check for user_question case
- Add proper null handling for last_message and all_messages cases
- Remove @ts-ignore comments with proper typing

* Update LLMNode.ts

* Update Agent.ts

---------

Co-authored-by: Henry Heng <henryheng@flowiseai.com>

packages/components/nodes/sequentialagents/LLMNode/LLMNode.ts

@@ -14,7 +14,8 @@ import {
     MessageContentImageUrl,
     INodeOutputsValue,
     ISeqAgentNode,
-    IDatabaseEntity
+    IDatabaseEntity,
+    ConversationHistorySelection
 } from '../../../src/Interface'
 import { AgentExecutor } from '../../../src/agents'
 import { getInputVariables, getVars, handleEscapeCharacters, prepareSandboxVars } from '../../../src/utils'
@@ -25,6 +26,7 @@ import {
     getVM,
     processImageMessage,
     transformObjectPropertyToFunction,
+    filterConversationHistory,
     restructureMessages,
     checkMessageHistory
 } from '../commonUtils'
@@ -173,7 +175,7 @@ class LLMNode_SeqAgents implements INode {
     constructor() {
         this.label = 'LLM Node'
         this.name = 'seqLLMNode'
-        this.version = 3.0
+        this.version = 4.0
         this.type = 'LLMNode'
         this.icon = 'llmNode.svg'
         this.category = 'Sequential Agents'
@@ -195,6 +197,53 @@ class LLMNode_SeqAgents implements INode {
                 optional: true,
                 additionalParams: true
             },
+            {
+                label: 'Prepend Messages History',
+                name: 'messageHistory',
+                description:
+                    'Prepend a list of messages between System Prompt and Human Prompt. This is useful when you want to provide few shot examples',
+                type: 'code',
+                hideCodeExecute: true,
+                codeExample: messageHistoryExample,
+                optional: true,
+                additionalParams: true
+            },
+            {
+                label: 'Conversation History',
+                name: 'conversationHistorySelection',
+                type: 'options',
+                options: [
+                    {
+                        label: 'User Question',
+                        name: 'user_question',
+                        description: 'Use the user question from the historical conversation messages as input.'
+                    },
+                    {
+                        label: 'Last Conversation Message',
+                        name: 'last_message',
+                        description: 'Use the last conversation message from the historical conversation messages as input.'
+                    },
+                    {
+                        label: 'All Conversation Messages',
+                        name: 'all_messages',
+                        description: 'Use all conversation messages from the historical conversation messages as input.'
+                    },
+                    {
+                        label: 'Empty',
+                        name: 'empty',
+                        description:
+                            'Do not use any messages from the conversation history. ' +
+                            'Ensure to use either System Prompt, Human Prompt, or Messages History.'
+                    }
+                ],
+                default: 'all_messages',
+                optional: true,
+                description:
+                    'Select which messages from the conversation history to include in the prompt. ' +
+                    'The selected messages will be inserted between the System Prompt (if defined) and ' +
+                    '[Messages History, Human Prompt].',
+                additionalParams: true
+            },
             {
                 label: 'Human Prompt',
                 name: 'humanMessagePrompt',
@@ -204,17 +253,6 @@ class LLMNode_SeqAgents implements INode {
                 optional: true,
                 additionalParams: true
             },
-            {
-                label: 'Messages History',
-                name: 'messageHistory',
-                description:
-                    'Return a list of messages between System Prompt and Human Prompt. This is useful when you want to provide few shot examples',
-                type: 'code',
-                hideCodeExecute: true,
-                codeExample: messageHistoryExample,
-                optional: true,
-                additionalParams: true
-            },
             {
                 label: 'Start | Agent | Condition | LLM | Tool Node',
                 name: 'sequentialNode',
@@ -534,6 +572,9 @@ async function agentNode(
             throw new Error('Aborted!')
         }
 
+        const historySelection = (nodeData.inputs?.conversationHistorySelection || 'all_messages') as ConversationHistorySelection
+        // @ts-ignore
+        state.messages = filterConversationHistory(historySelection, input, state)
         // @ts-ignore
         state.messages = restructureMessages(llm, state)