ChatGPT-Next-Web/app/api/langchain-tools/stable_diffusion_image_generator.ts

import { Tool } from "@langchain/core/tools";
import S3FileStorage from "../../utils/s3_file_storage";

export class StableDiffusionWrapper extends Tool {
  name = "stable_diffusion_image_generator";

  constructor() {
    super();
  }

  async saveImage(imageBase64: string) {
    const buffer = Buffer.from(imageBase64, "base64");
    var fileName = `${Date.now()}.png`;
    const filePath = await S3FileStorage.put(fileName, buffer);
    return filePath;
  }

  /** @ignore */
  async _call(prompt: string) {
    let url = process.env.STABLE_DIFFUSION_API_URL;
    const data = {
      prompt: prompt,
      negative_prompt:
        process.env.STABLE_DIFFUSION_NEGATIVE_PROMPT ??
        "longbody, lowres, bad anatomy, bad hands, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality",
      seed: -1,
      subseed: -1,
      subseed_strength: 0,
      batch_size: 1,
      n_iter: 1,
      steps: process.env.STABLE_DIFFUSION_STEPS ?? 20,
      cfg_scale: process.env.STABLE_DIFFUSION_CFG_SCALE ?? 7,
      width: process.env.STABLE_DIFFUSION_WIDTH ?? 720,
      height: process.env.STABLE_DIFFUSION_HEIGHT ?? 720,
      restore_faces: process.env.STABLE_DIFFUSION_RESTORE_FACES ?? false,
      eta: 0,
      sampler_index: process.env.STABLE_DIFFUSION_SAMPLER_INDEX ?? "Euler a",
    };
    console.log(`[${this.name}]`, data);
    const response = await fetch(`${url}/sdapi/v1/txt2img`, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify(data),
    });
    const json = await response.json();
    let imageBase64 = json.images[0];
    if (!imageBase64) return "No image was generated";
    const filePath = await this.saveImage(imageBase64);
    console.log(`[${this.name}]`, filePath);
    return filePath;
  }

  description = `stable diffusion is an ai art generation model similar to dalle-2.
    input requires english.
    output will be the image link url.
    use markdown to display images. like: ![img](/api/file/xxx.png)`;
}