Flowise/packages/components/nodes/chains/LLMChain/LLMChain.ts

100 lines
3.1 KiB
TypeScript

import { INode, INodeData, INodeParams } from '../../../src/Interface'
import { getBaseClasses } from '../../../src/utils'
import { LLMChain } from 'langchain/chains'
import { BaseLanguageModel } from 'langchain/base_language'
import { BasePromptTemplate } from 'langchain/prompts'
class LLMChain_Chains implements INode {
label: string
name: string
type: string
icon: string
category: string
baseClasses: string[]
description: string
inputs: INodeParams[]
constructor() {
this.label = 'LLM Chain'
this.name = 'llmChain'
this.type = 'LLMChain'
this.icon = 'chain.svg'
this.category = 'Chains'
this.description = 'Chain to run queries against LLMs'
this.baseClasses = [this.type, ...getBaseClasses(LLMChain)]
this.inputs = [
{
label: 'Language Model',
name: 'model',
type: 'BaseLanguageModel'
},
{
label: 'Prompt',
name: 'prompt',
type: 'BasePromptTemplate'
},
{
label: 'Format Prompt Values',
name: 'promptValues',
type: 'string',
rows: 5,
placeholder: `{
"input_language": "English",
"output_language": "French"
}`,
optional: true
}
]
}
async init(nodeData: INodeData): Promise<any> {
const model = nodeData.inputs?.model as BaseLanguageModel
const prompt = nodeData.inputs?.prompt as BasePromptTemplate
const chain = new LLMChain({ llm: model, prompt })
return chain
}
async run(nodeData: INodeData, input: string): Promise<string> {
const inputVariables = nodeData.instance.prompt.inputVariables as string[] // ["product"]
const chain = nodeData.instance as LLMChain
if (inputVariables.length === 1) {
const res = await chain.run(input)
return res
} else if (inputVariables.length > 1) {
const promptValuesStr = nodeData.inputs?.promptValues as string
if (!promptValuesStr) throw new Error('Please provide Prompt Values')
const promptValues = JSON.parse(promptValuesStr.replace(/\s/g, ''))
let seen: string[] = []
for (const variable of inputVariables) {
seen.push(variable)
if (promptValues[variable]) {
seen.pop()
}
}
if (seen.length === 1) {
const lastValue = seen.pop()
if (!lastValue) throw new Error('Please provide Prompt Values')
const options = {
...promptValues,
[lastValue]: input
}
const res = await chain.call(options)
return res?.text
} else {
throw new Error('Please provide Prompt Values')
}
} else {
const res = await chain.run(input)
return res
}
}
}
module.exports = { nodeClass: LLMChain_Chains }