Flowise/packages/components/nodes/engine/ChatEngine/SimpleChatEngine.ts

126 lines
3.9 KiB
TypeScript

import { FlowiseMemory, ICommonObject, IMessage, INode, INodeData, INodeOutputsValue, INodeParams } from '../../../src/Interface'
import { LLM, ChatMessage, SimpleChatEngine } from 'llamaindex'
class SimpleChatEngine_LlamaIndex implements INode {
label: string
name: string
version: number
description: string
type: string
icon: string
category: string
baseClasses: string[]
tags: string[]
inputs: INodeParams[]
outputs: INodeOutputsValue[]
sessionId?: string
constructor(fields?: { sessionId?: string }) {
this.label = 'Simple Chat Engine'
this.name = 'simpleChatEngine'
this.version = 1.0
this.type = 'SimpleChatEngine'
this.icon = 'chat-engine.png'
this.category = 'Engine'
this.description = 'Simple engine to handle back and forth conversations'
this.baseClasses = [this.type]
this.tags = ['LlamaIndex']
this.inputs = [
{
label: 'Chat Model',
name: 'model',
type: 'BaseChatModel_LlamaIndex'
},
{
label: 'Memory',
name: 'memory',
type: 'BaseChatMemory'
},
{
label: 'System Message',
name: 'systemMessagePrompt',
type: 'string',
rows: 4,
optional: true,
placeholder: 'You are a helpful assistant'
}
]
this.sessionId = fields?.sessionId
}
async init(): Promise<any> {
return null
}
async run(nodeData: INodeData, input: string, options: ICommonObject): Promise<string> {
const model = nodeData.inputs?.model as LLM
const systemMessagePrompt = nodeData.inputs?.systemMessagePrompt as string
const memory = nodeData.inputs?.memory as FlowiseMemory
const prependMessages = options?.prependMessages
const chatHistory = [] as ChatMessage[]
if (systemMessagePrompt) {
chatHistory.push({
content: systemMessagePrompt,
role: 'user'
})
}
const chatEngine = new SimpleChatEngine({ llm: model })
const msgs = (await memory.getChatMessages(this.sessionId, false, prependMessages)) as IMessage[]
for (const message of msgs) {
if (message.type === 'apiMessage') {
chatHistory.push({
content: message.message,
role: 'assistant'
})
} else if (message.type === 'userMessage') {
chatHistory.push({
content: message.message,
role: 'user'
})
}
}
let text = ''
let isStreamingStarted = false
const isStreamingEnabled = options.socketIO && options.socketIOClientId
if (isStreamingEnabled) {
const stream = await chatEngine.chat({ message: input, chatHistory, stream: true })
for await (const chunk of stream) {
text += chunk.response
if (!isStreamingStarted) {
isStreamingStarted = true
options.socketIO.to(options.socketIOClientId).emit('start', chunk.response)
}
options.socketIO.to(options.socketIOClientId).emit('token', chunk.response)
}
} else {
const response = await chatEngine.chat({ message: input, chatHistory })
text = response?.response
}
await memory.addChatMessages(
[
{
text: input,
type: 'userMessage'
},
{
text: text,
type: 'apiMessage'
}
],
this.sessionId
)
return text
}
}
module.exports = { nodeClass: SimpleChatEngine_LlamaIndex }