Function prepareAgent

packages/components/nodes/agents/XMLAgent/XMLAgent.ts:218–289

(
    nodeData: INodeData,
    options: ICommonObject,
    flowObj: { sessionId?: string; chatId?: string; input?: string }
)

}

const prepareAgent = async (
    nodeData: INodeData,
    options: ICommonObject,
    flowObj: { sessionId?: string; chatId?: string; input?: string }
) => {
    const model = nodeData.inputs?.model as BaseChatModel
    const maxIterations = nodeData.inputs?.maxIterations as string
    const memory = nodeData.inputs?.memory as FlowiseMemory
    let systemMessage = nodeData.inputs?.systemMessage as string
    let tools = nodeData.inputs?.tools
    tools = flatten(tools)
    const inputKey = memory.inputKey ? memory.inputKey : 'input'
    const memoryKey = memory.memoryKey ? memory.memoryKey : 'chat_history'
    const prependMessages = options?.prependMessages

    systemMessage = transformBracesWithColon(systemMessage)

    let promptMessage = systemMessage ? systemMessage : defaultSystemMessage
    if (memory.memoryKey) promptMessage = promptMessage.replaceAll('{chat_history}', `{${memory.memoryKey}}`)
    if (memory.inputKey) promptMessage = promptMessage.replaceAll('{input}', `{${memory.inputKey}}`)

    const prompt = ChatPromptTemplate.fromMessages([
        HumanMessagePromptTemplate.fromTemplate(promptMessage),
        new MessagesPlaceholder('agent_scratchpad')
    ])

    const missingVariables = ['tools', 'agent_scratchpad'].filter((v) => !prompt.inputVariables.includes(v))

    if (missingVariables.length > 0) {
        throw new Error(`Provided prompt is missing required input variables: ${JSON.stringify(missingVariables)}`)
    }

    const llmWithStop = (model as BaseLanguageModel).withConfig({
        stop: ['</tool_input>', '</final_answer>']
    })

    const messages = (await memory.getChatMessages(flowObj.sessionId, false, prependMessages)) as IMessage[]
    let chatHistoryMsgTxt = ''
    for (const message of messages) {
        if (message.type === 'apiMessage') {
            chatHistoryMsgTxt += `\\nAI:${message.message}`
        } else if (message.type === 'userMessage') {
            chatHistoryMsgTxt += `\\nHuman:${message.message}`
        }
    }

    const runnableAgent = RunnableSequence.from([
        {
            [inputKey]: (i: { input: string; tools: Tool[]; steps: AgentStep[] }) => i.input,
            agent_scratchpad: (i: { input: string; tools: Tool[]; steps: AgentStep[] }) => formatLogToMessage(i.steps),
            tools: (_: { input: string; tools: Tool[]; steps: AgentStep[] }) =>
                tools.map((tool: Tool) => `${tool.name}: ${tool.description}`),
            [memoryKey]: (_: { input: string; tools: Tool[]; steps: AgentStep[] }) => chatHistoryMsgTxt
        },
        prompt,
        llmWithStop,
        new XMLAgentOutputParser()
    ])