nuxt.generate.js

const axios = require('axios');

// From: https://www.storyblok.com/faq/how-to-generate-routes-for-nuxt-js-using-storyblok
module.exports = function generateStoryblokUrls(token) {
  return {
    routes: function(callback) {
      const per_page = 10;
      const version = 'published';
      let cache_version = 0;

      let page = 1;

      // other routes that are not in Storyblok with their slug.
      let routes = ['/']; // adds home directly but with / instead of /home

      // Load space and receive latest cache version key to improve performance
      axios.get(`https://api.storyblok.com/v1/cdn/spaces/me?token=${token}`).then(space_res => {
        // timestamp of latest publish
        cache_version = space_res.data.space.version;

        // Call first Page of the Stories
        axios
          .get(
            `https://api.storyblok.com/v1/cdn/stories?token=${token}&version=${version}&per_page=${per_page}&page=${page}&cv=${cache_version}`
          )
          .then(res => {
            res.data.stories.forEach(story => {
              if (story.full_slug != 'home') {
                routes.push('/' + story.full_slug);
              }
            });

            // Check if there are more pages available otherwise execute callback with current routes.
            const total = res.headers.total;
            const maxPage = Math.ceil(total / per_page);
            if (maxPage <= 1) {
              callback(null, routes);
              return;
            }

            // Since we know the total we now can pregenerate all requests we need to get all stories
            let contentRequests = [];
            for (let page = 2; page <= maxPage; page++) {
              contentRequests.push(
                axios.get(
                  `https://api.storyblok.com/v1/cdn/stories?token=${token}&version=${version}&per_page=${per_page}&page=${page}`
                )
              );
            }

            // Axios allows us to exectue all requests using axios.spread we will than generate our routes and execute the callback
            axios
              .all(contentRequests)
              .then(
                axios.spread((...responses) => {
                  responses.forEach(response => {
                    response.data.stories.forEach(story => {
                      if (story.full_slug != 'home') {
                        routes.push('/' + story.full_slug);
                      }
                    });
                  });

                  callback(null, routes);
                })
              )
              .catch(callback);
          });
      });
    }
  };
};