Text-to-Image API

Basic Example

POST /sdapi/v1/txt2img

{
  "prompt": "Sunset in the mountains, lake in front",
  "negative_prompt": "clouds, people",
  "sampler_name": "Euler",
  "steps": 20,
  "cfg_scale": 7,
  "height": 512,
  "width": 512,
  "seed": -1
}

High Resolution

To increase the resolution of the generated image, add the following params:

{
  "enable_hr": true,
  "hr_scale": 2,
  "denoising_strength": 0.7,
  "hr_second_pass_steps": 10,
  "hr_upscaler": "R-ESRGAN"
}

The hr-scale param multiplies the specified width and height (if the base resolution is 512x512, and the hr_scale is 2, then the output will be 1024x1024)

Response

Your response will contain an array of output images, and the values of all the parameters it used to generate the images:

{
  "images": ["iVBORw0KGgoAAAANSUhEUgAAA..."],
  "parameters": {
    "enable_hr": false,
    "denoising_strength": 0,
    "firstphase_width": 0,
    "firstphase_height": 0,
    "hr_scale": 2.0,
    "hr_upscaler": null,
    "hr_second_pass_steps": 0,
    "hr_resize_x": 0,
    "hr_resize_y": 0,
    "prompt": "Astronaut planting a flag on the moon",
    "styles": null,
    "seed": -1,
    "subseed": -1,
    "subseed_strength": 0,
    "seed_resize_from_h": -1,
    "seed_resize_from_w": -1,
    "sampler_name": null,
    "batch_size": 1,
    "n_iter": 1,
    "steps": 20,
    "cfg_scale": 7.0,
    "width": 512,
    "height": 512,
    "restore_faces": false,
    "tiling": false,
    "do_not_save_samples": false,
    "do_not_save_grid": false,
    "negative_prompt": "",
    "eta": null,
    "s_min_uncond": 0.0,
    "s_churn": 0.0,
    "s_tmax": null,
    "s_tmin": 0.0,
    "s_noise": 1.0,
    "override_settings": null,
    "override_settings_restore_afterwards": true,
    "script_args": [],
    "sampler_index": "Euler",
    "script_name": null,
    "send_images": true,
    "save_images": false,
    "alwayson_scripts": {}
  }
}

The number of images depends on what you specified for a batch size. The images are in base64 format, and therefore need to be decoded and saved to the file system as normal images:

result.images.forEach((img, i) => {
  const buf = Buffer.from(img, 'base64');
  fs.writeFileSync(`image-${i}.png`, buf);
});

Full Example

Here is a full javascript (nodejs) example:

const result = await fetch('[server]:7860/sdapi/v1/txt2img', {
  method: 'POST',
  body: JSON.stringify({
    prompt: "Sunset in the mountains, lake in front",
    negative_prompt: "clouds, people",
    sampler_name: "Euler",
    steps: 20,
    cfg_scale: 7,
    height: 512,
    width: 512
  })
}).then(res => res.json());
result.images.forEach((img, i) => {
  const buf = Buffer.from(img, 'base64');
  fs.writeFileSync(`image-${i}.png`, buf);
});

Control Net

See the ControlNet API guide for sending in a control input image

Full List of params

This is the full list of params that can be used for the txt2img endpoint: