https://lihbr.com/blog/adding-algolia-search-to-your-jamstack-website

buildIndices.js

/**
 * Import
 */
require("dotenv").config();
const algoliasearch = require("algoliasearch");
const cheerio = require("cheerio");

/**
 * Check for environmnent variables
 */
for (key of ["ALGOLIA_APP_ID", "ALGOLIA_SEARCH_KEY", "ALGOLIA_ADMIN_KEY"]) {
  if (typeof process.env[key] === "undefined") {
    console.warn(
      `Algolia require ${key} env variable in order to build index, disabling search engine...`
    );
    process.exit(0);
  }
}

/**
 * Functions
 */

/**
 * Get posts content from API
 * @param {String} locale - locale to get posts in
 * @return {Array} - retrieved posts
 */
const getPosts = (locale) => {
  // Depends on your API reference ;)
};

/**
 * Get search records for a given post
 * @param {Object} post - a blog post
 * @return {Array} - an array of records for that blog post
 */
const getRecordsForPost = post => {
  const records = [];

  // 1. Define tag importance
  const importanceRanking = {
    title: 0,
    lead: 1,
    h2: 2,
    h3: 3,
    h4: 4,
    default: 5
  };

  // Create a standardized record function helper
  const createRecord = (key, importance, content) => ({
    objectID: `${post.uuid}-${key}`,
    slug: post.slug,
    title: post.title,
    importance,
    content
  });

  // 2. Add title and lead to records
  records.push(createRecord("title", importanceRanking.title, post.title));
  records.push(createRecord("lead", importanceRanking.lead, post.lead));

  // 3. Split post body by tag and add them to records
  const $ = cheerio.load(post.body);
  $("body")
    .children()
    .each((i, el) => {
      const key = `${el.name}-${i}`;
      const importance =
        importanceRanking[el.name] || importanceRanking.default;
      records.push(createRecord(key, importance, $(el).text().slice(0, 5000)));
    });

  // 4. Return only records with a non null content
  return records.filter(record => !!record.content.trim());
};

/**
 * Scripting
 */

// Init Algolia client
const client = algoliasearch(
  process.env.ALGOLIA_APP_ID,
  process.env.ALGOLIA_ADMIN_KEY
);

// Loop through locales to build an index for each of those
for (const locale of ["en", "fr", "de"]) {
  // 1. Getting posts from your API
  let posts = getPosts(locale);

  // 2. Creating records
  const records = [];
  for (const post of posts) {
    records.push(...getRecordsForPost(post));
  }

  // 3. Sending records to Algolia
  const index = client.initIndex(`blogPost-${locale}`);
  index.replaceAllObjects(records, {}).then(() => {
    console.info(
      `Algolia Search: Successfully saved ${records.length} objects to index "blogPost-${locale}"`
    );
  });
}