@beparallel/langchain-ts/src/parser.ts

Extracts Langchain prompts and generates TypeScript types.

import { ChatPromptTemplate } from '@langchain/core/prompts';
import console from 'console';
import * as hub from 'langchain/hub';

import { Client } from 'langsmith';

export async function extractPrompts({
  langchainApiKey,
  langchainTag,
}: {
  langchainApiKey: string;
  langchainTag: string;
}): Promise<ChatPromptTemplate[]> {
  const client = new Client({ apiKey: langchainApiKey });

  const prompts = await client.listPrompts({
    isPublic: false,
    isArchived: false,
    sortField: 'updated_at',
  });
  const result: ChatPromptTemplate[] = [];

  for await (const prompt of prompts) {
    console.debug(`Generating prompt ${prompt.repo_handle}`);
    try {
      const chatPromptTemplate = await hub.pull<ChatPromptTemplate>(
        `${prompt.repo_handle}:${langchainTag}`,
      );
      result.push(chatPromptTemplate);
    } catch (error) {
      console.error(error);
    }
  }

  return result;
}