qa_youtube_metal_langchain.tsx

const saveToMetal = async (text, videoId) => {
  const body = {
    index: INDEX_ID,
    text: text,
    metadata: { videoId },
  }

  const options = {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-metal-api-key': API_KEY,
      'x-metal-client-id': CLIENT_ID,
    },
    body: JSON.stringify(body),
  }

  const documents = await fetch('https://api.getmetal.io/v1/index', options)
    .then((response) => response.json())
    .catch((err) => console.error(err))
  return documents
}

/**
 * Fetch transcript and save the embeddings to db
 */
const storeVideo = async () => {
  const transcriptArray = await YoutubeTranscript.fetchTranscript(videoId).catch(
    (error) => { 
      throw new Error(error.message)
    },
  )

  const transcript = reduceTranscript(transcriptArray)

  const textSplitter = new RecursiveCharacterTextSplitter({ chunkSize: 1000 })
  const docs = await textSplitter.createDocuments([transcript])

  // Save chunks to Metal
  for (const doc of docs) {
    await saveToMetal(doc.pageContent, videoId)
  }
}

const getEmbeddings = async (query, videoId) => {
  try {
    const response = await fetch('https://api.getmetal.io/v1/search', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-metal-api-key': API_KEY,
        'x-metal-client-id': CLIENT_ID,
      },
      body: JSON.stringify({
        index: INDEX_ID,
        text: query,
        filters: [
          {
            field: 'videoId',
            value: videoId,
          },
        ],
      }),
    })

    return response.json()
  } catch (error) {
    throw error
  }
}

async function getDocuments(query, videoId) {
  const response = await getEmbeddings(query, videoId)

  return response.data.map(
    ({ text, metadata }) =>
      new Document({
        pageContent: text,
        metadata: metadata,
      }),
  )
}

/**
 * QA Youtube Video
 */
const askVideo = async (message) => {
  const docs = await getRelevantDocuments(message, videoId)
  const llm = new ChatOpenAI({
    temperature: 0.7,
  })

  const chain = loadQAStuffChain(llm)
  const answer = await chain
    .call({
      input_documents: docs,
      question: message,
    })
    .catch((e) => console.error(e))

  console.log(answer)
}