add conversation chain

2026-06-28 13:00:56 +03:00 · 2023-05-22 13:38:31 +01:00
parent 913eebab4f
commit de4e4a63de
4 changed files with 386 additions and 1 deletions
@@ -0,0 +1,97 @@
+import { ICommonObject, IMessage, INode, INodeData, INodeParams } from '../../../src/Interface'
+import { ConversationChain } from 'langchain/chains'
+import { getBaseClasses } from '../../../src/utils'
+import { ChatPromptTemplate, HumanMessagePromptTemplate, MessagesPlaceholder, SystemMessagePromptTemplate } from 'langchain/prompts'
+import { BufferMemory, ChatMessageHistory } from 'langchain/memory'
+import { BaseChatModel } from 'langchain/chat_models/base'
+import { AIChatMessage, HumanChatMessage } from 'langchain/schema'
+
+const systemMessage = `The following is a friendly conversation between a human and an AI. The AI is talkative and provides lots of specific details from its context. If the AI does not know the answer to a question, it truthfully says it does not know.`
+
+class ConversationChain_Chains implements INode {
+    label: string
+    name: string
+    type: string
+    icon: string
+    category: string
+    baseClasses: string[]
+    description: string
+    inputs: INodeParams[]
+
+    constructor() {
+        this.label = 'Conversation Chain'
+        this.name = 'conversationChain'
+        this.type = 'ConversationChain'
+        this.icon = 'chain.svg'
+        this.category = 'Chains'
+        this.description = 'Chat models specific conversational chain with memory'
+        this.baseClasses = [this.type, ...getBaseClasses(ConversationChain)]
+        this.inputs = [
+            {
+                label: 'Language Model',
+                name: 'model',
+                type: 'BaseChatModel'
+            },
+            {
+                label: 'Memory',
+                name: 'memory',
+                type: 'BaseMemory'
+            },
+            {
+                label: 'System Message',
+                name: 'systemMessagePrompt',
+                type: 'string',
+                rows: 4,
+                additionalParams: true,
+                optional: true,
+                placeholder: 'You are a helpful assistant that write codes'
+            }
+        ]
+    }
+
+    async init(nodeData: INodeData): Promise<any> {
+        const model = nodeData.inputs?.model as BaseChatModel
+        const memory = nodeData.inputs?.memory as BufferMemory
+        const prompt = nodeData.inputs?.systemMessagePrompt as string
+
+        const obj: any = {
+            llm: model,
+            memory
+        }
+
+        const chatPrompt = ChatPromptTemplate.fromPromptMessages([
+            SystemMessagePromptTemplate.fromTemplate(prompt ? `${prompt}\n${systemMessage}` : systemMessage),
+            new MessagesPlaceholder(memory.memoryKey ?? 'chat_history'),
+            HumanMessagePromptTemplate.fromTemplate('{input}')
+        ])
+        obj.prompt = chatPrompt
+
+        const chain = new ConversationChain(obj)
+        return chain
+    }
+
+    async run(nodeData: INodeData, input: string, options: ICommonObject): Promise<string> {
+        const chain = nodeData.instance as ConversationChain
+        const memory = nodeData.inputs?.memory as BufferMemory
+
+        if (options && options.chatHistory) {
+            const chatHistory = []
+            const histories: IMessage[] = options.chatHistory
+
+            for (const message of histories) {
+                if (message.type === 'apiMessage') {
+                    chatHistory.push(new AIChatMessage(message.message))
+                } else if (message.type === 'userMessage') {
+                    chatHistory.push(new HumanChatMessage(message.message))
+                }
+            }
+            memory.chatHistory = new ChatMessageHistory(chatHistory)
+            chain.memory = memory
+        }
+
+        const res = await chain.call({ input })
+        return res?.response
+    }
+}
+
+module.exports = { nodeClass: ConversationChain_Chains }
@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" class="icon icon-tabler icon-tabler-dna" width="24" height="24" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" fill="none" stroke-linecap="round" stroke-linejoin="round">
+   <path stroke="none" d="M0 0h24v24H0z" fill="none"></path>
+   <path d="M14.828 14.828a4 4 0 1 0 -5.656 -5.656a4 4 0 0 0 5.656 5.656z"></path>
+   <path d="M9.172 20.485a4 4 0 1 0 -5.657 -5.657"></path>
+   <path d="M14.828 3.515a4 4 0 0 0 5.657 5.657"></path>
+</svg>