routes/prompt/index.js

'use strict'

const nodeCache = require('node-cache');
const dotenv = require('dotenv');
const HfInference = require('@huggingface/inference').HfInference;

dotenv.config();

const inference = new HfInference(process.env.HF_TOKEN);
const cache = new nodeCache(
  {
    stdTTL: 60 * 60 * 24,
    checkperiod: 60 * 60,
    useClones: false
  }
);

const REPO_NAME = "black-forest-labs/FLUX.1-schnell"

module.exports = async function (fastify, opts) {
  fastify.get('/:inputs', async function (request, reply) {
    const { inputs } = request.params;
    const slug = inputs.replace(/[^a-zA-Z0-9]/g, '');

    if (cache.get(slug)) {
      const image = await cache.get(slug);
      console.log("Cache hit")
      return reply
        .header('Content-Type', 'image/jpeg')
        .send(image);
    }

    const hfRequest = await inference.textToImage({
      inputs,
      model: REPO_NAME,
    })

    const buffer = await hfRequest.arrayBuffer();
    const array = new Uint8Array(buffer);

    cache.set(slug, array);

    return reply
      .header('Content-Type', 'image/jpeg')
      .send(array);
  })
}