@n8n/n8n-nodes-langchain
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JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.processItem = processItem;
const messages_1 = require("@langchain/core/messages");
const prompts_1 = require("@langchain/core/prompts");
const n8n_workflow_1 = require("n8n-workflow");
const tracing_1 = require("../../../utils/tracing");
const constants_1 = require("./constants");
async function processItem(ctx, itemIndex, llm, parser) {
const input = ctx.getNodeParameter('text', itemIndex);
if (!input?.trim()) {
throw new n8n_workflow_1.NodeOperationError(ctx.getNode(), `Text for item ${itemIndex} is not defined`, {
itemIndex,
});
}
const inputPrompt = new messages_1.HumanMessage(input);
const options = ctx.getNodeParameter('options', itemIndex, {});
const escapedTemplate = (options.systemPromptTemplate ?? constants_1.SYSTEM_PROMPT_TEMPLATE).replace(/[{}]/g, (match) => match + match);
const systemPromptTemplate = prompts_1.SystemMessagePromptTemplate.fromTemplate(`${escapedTemplate}
{format_instructions}`);
const messages = [
await systemPromptTemplate.format({
format_instructions: parser.getFormatInstructions(),
}),
inputPrompt,
];
const prompt = prompts_1.ChatPromptTemplate.fromMessages(messages);
const chain = prompt.pipe(llm).pipe(parser).withConfig((0, tracing_1.getTracingConfig)(ctx));
return await chain.invoke(messages);
}
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