app.py

import random
import torch
import gradio as gr
import spaces

from huggingface_hub import hf_hub_download
from safetensors.torch import load_file

from diffusers import ZImagePipeline, ZImageTransformer2DModel

BASE_ID = "Tongyi-MAI/Z-Image-Turbo"
CUSTOM_REPO = "MutantSparrow/Ray"
CUSTOM_FILE = "Z-IMAGE-TURBO/Rayzist.v1.0.safetensors"

FIXED_STEPS = 8
GUIDANCE = 1.0

pipe = None

def load_pipe():
    global pipe
    if pipe is not None:
        return pipe

    transformer = ZImageTransformer2DModel.from_pretrained(
        BASE_ID,
        subfolder="transformer",
        torch_dtype=torch.bfloat16,
    )

    pipe = ZImagePipeline.from_pretrained(
        BASE_ID,
        transformer=transformer,
        torch_dtype=torch.bfloat16,
    ).to("cuda")

    ckpt_path = hf_hub_download(CUSTOM_REPO, CUSTOM_FILE)
    state = load_file(ckpt_path)

    missing, unexpected = pipe.transformer.load_state_dict(state, strict=False)
    print("Loaded custom weights.")
    print("Missing keys:", len(missing))
    print("Unexpected keys:", len(unexpected))

    pipe.set_progress_bar_config(disable=True)
    return pipe

@spaces.GPU
def generate(prompt, height, width):
    p = load_pipe()

    # Random seed every run
    seed = random.randint(0, 2**31 - 1)
    g = torch.Generator("cuda").manual_seed(seed)

    img = p(
        prompt=prompt,
        height=int(height),
        width=int(width),
        num_inference_steps=FIXED_STEPS,
        guidance_scale=GUIDANCE,
        generator=g,
    ).images[0]

    return img, seed

with gr.Blocks() as demo:
    gr.Markdown("Ray's Z-Image Turbo finetune: RAYZIST!")

    prompt = gr.Textbox(label="Prompt", lines=3)
    width  = gr.Dropdown([512, 768, 1024, 1280, 1344], value=1024, label="Width")
    height = gr.Dropdown([512, 768, 1024, 1280, 1344], value=1024, label="Height")

    # Button ABOVE output
    btn = gr.Button("GO>")
    out = gr.Image(label="Your image")
    seed_info = gr.Markdown()

    def _run(prompt, height, width):
        img, seed = generate(prompt, height, width)
        return img, f"Seed: `{seed}`"

    btn.click(_run, [prompt, height, width], [out, seed_info])

demo.queue()
demo.launch()