app.py

import gradio as gr
from transformers import AutoTokenizer, AutoModelForSequenceClassification
import torch

model_path = "modernbert.bin"
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')

tokenizer = AutoTokenizer.from_pretrained("answerdotai/ModernBERT-base")
model = AutoModelForSequenceClassification.from_pretrained("answerdotai/ModernBERT-base", num_labels=41)
model.load_state_dict(torch.load(model_path, map_location=device))
model.to(device).eval()

label_mapping = {
    0: '13B', 1: '30B', 2: '65B', 3: '7B', 4: 'GLM130B', 5: 'bloom_7b',
    6: 'bloomz', 7: 'cohere', 8: 'davinci', 9: 'dolly', 10: 'dolly-v2-12b',
    11: 'flan_t5_base', 12: 'flan_t5_large', 13: 'flan_t5_small', 
    14: 'flan_t5_xl', 15: 'flan_t5_xxl', 16: 'gemma-7b-it', 17: 'gemma2-9b-it',
    18: 'gpt-3.5-turbo', 19: 'gpt-35', 20: 'gpt4', 21: 'gpt4o', 
    22: 'gpt_j', 23: 'gpt_neox', 24: 'human', 25: 'llama3-70b', 26: 'llama3-8b',
    27: 'mixtral-8x7b', 28: 'opt_1.3b', 29: 'opt_125m', 30: 'opt_13b',
    31: 'opt_2.7b', 32: 'opt_30b', 33: 'opt_350m', 34: 'opt_6.7b',
    35: 'opt_iml_30b', 36: 'opt_iml_max_1.3b', 37: 't0_11b', 38: 't0_3b',
    39: 'text-davinci-002', 40: 'text-davinci-003'
}

def classify_text(text):
    if not text.strip():
        return "----"

    inputs = tokenizer(text, return_tensors="pt", truncation=True, padding=True).to(device)

    with torch.no_grad():
        probabilities = torch.softmax(model(**inputs).logits, dim=1)[0]

    ai_probs = probabilities.clone()
    ai_probs[24] = 0
    ai_total_prob = ai_probs.sum().item() * 100
    human_prob = 100 - ai_total_prob

    ai_argmax_index = torch.argmax(ai_probs).item()
    ai_argmax_model = label_mapping[ai_argmax_index]

    if human_prob > ai_total_prob:
        result_message = (
            f"✅ - The text is <span class='highlight-human'>**{human_prob:.2f}%** likely <b>Human written</b>.</span>"
        )
    else:
        result_message = (
            f"🤖 - The text is <span class='highlight-ai'>**{ai_total_prob:.2f}%** likely <b>AI generated</b>.</span>\n\n"
            f"**Identified AI Model:** {ai_argmax_model}"
        )

    return result_message



title = "AI Text Detector"

description = """

This tool uses the **ModernBERT** model to identify whether a given text was written by a human or generated by artificial intelligence (AI).

<br>

<div style="line-height: 1.8;">
✅ <b>Human Verification:</b> Human-written content is clearly marked.<br>
🔍 <b>Model Detection:</b> Can identify content from over 40 AI models.<br>
📈 <b>Accuracy:</b> Works best with longer texts for improved precision.
</div>

<br>

Paste your text below to analyze its origin.
"""
bottom_text = "**Developed by SzegedAI**"

iface = gr.Blocks(css="""
    @import url('https://fonts.googleapis.com/css2?family=Roboto+Mono:wght@400;700&display=swap');

    #text_input_box {
        border-radius: 10px;
        border: 2px solid #4CAF50;
        font-size: 18px;
        padding: 15px;
        margin-bottom: 20px;
        width: 60%;
        box-sizing: border-box;
        margin: auto;
    }
    .form.svelte-633qhp {
        background: none;
        border: none;
        box-shadow: none;
    }

    #result_output_box {
        border-radius: 10px;
        border: 2px solid #4CAF50;
        font-size: 18px;
        padding: 15px;
        margin-top: 20px;
        width: 40%;
        box-sizing: border-box;
        text-align: center;
        margin: auto;
    }

    @media (max-width: 768px) {
        #result_output_box {
            width: 100%;
        }
	#text_input_box{
	    width: 100%;
	}
    }

    body {
        font-family: 'Roboto Mono', sans-serif !important;
        padding: 20px;
        display: block;
        justify-content: center;
        align-items: center;
        height: 100vh;
        overflow-y: auto;
    }

    .gradio-container {
        border: 1px solid #4CAF50;
        border-radius: 15px;
        padding: 30px;
        box-shadow: 0px 0px 10px rgba(0,255,0,0.6);
        max-width: 600px;
        margin: auto;
	overflow-y: auto;
    }

    h1 {
        text-align: center;
        font-size: 32px;
        font-weight: bold;
        margin-bottom: 30px;
    }

    .highlight-human {
        color: #4CAF50;
        font-weight: bold;
        background: rgba(76, 175, 80, 0.2);
        padding: 5px;
        border-radius: 8px;
    }

    .highlight-ai {
        color: #FF5733;
        font-weight: bold;
        background: rgba(255, 87, 51, 0.2);
        padding: 5px;
        border-radius: 8px;
    }
    #bottom_text {
        text-align: center;
        margin-top: 50px;
        font-weight: bold;
        font-size: 20px;
    }
    .block.svelte-11xb1hd{
	background: none !important;
    }
""")

with iface:
    gr.Markdown(f"# {title}")
    gr.Markdown(description)
    text_input = gr.Textbox(label="", placeholder="Type or paste your content here...", elem_id="text_input_box", lines=5)
    result_output = gr.Markdown("**Results will appear here...**", elem_id="result_output_box")
    text_input.change(classify_text, inputs=text_input, outputs=result_output)
    gr.Markdown(bottom_text, elem_id="bottom_text")

iface.launch(share=True)