Bare minimum example of Prismic API exposed as a Nuxt.js plugin

PrismicApi.js

/**
 * Prismic API
 * Creates a prismic api instance on the app, for use in asyncData for loading content.
 */
import Vue from 'vue';
import prismic from 'prismic-javascript';

export default ({ app, env, error }) => {
	const PrismicApi = {
		// use this to access singular api instance in app
		// in vue: this.prismic.api
		// in asyncData/fetch: app.prismic.api
		api: {
			// This default object, prevents failures when calling `this.prismic.api.query` before it
			// has fully initialized. This will be overwritten when its ready.
			// This is mostly to track which pages are causing the call to occur early, for improved debugging
			query(queryPredicates) {
				if (process.client) {
					app.$raven.captureMessage('Prismic Called Before Creation', {
						extra: {
							error: 'prismic.api.query was called before prismic.getApi finished',
							queryPredicates,
						},
					});
				}
				error({ statusCode: 500, message: 'Something went wrong, please refresh and try again.' });
				return new Promise(resolve => resolve({ failed: true, results: [] }));
			},
		},

		// ready is true, when we've loaded the prismic api and not our default above.
		hasApi: false,

		// allows us to build queries via app.prismic.Predicates
		Predicates: prismic.Predicates,

		// returns existing api, or makes a new one for use in app via app.prismic.api
		async getApi() {
			this.api = await prismic.getApi(env.prismicApi, { accessToken: env.prismicToken })
				.catch((err) => {
					if (process.client) {
						app.$raven.captureMessage('Failed loading prismic api', { extra: { error: err } });
					}
					return error({ statusCode: 500, message: 'Something went wrong, please refresh and try again.' });
				});
		},
	};

	app.prismic = PrismicApi;
	Vue.prototype.prismic = PrismicApi;
}

Updated, to remove the preservation of api.

Should be making a new version for each request.