metadata

title: Canspace
emoji: 🐨
colorFrom: red
colorTo: purple
sdk: docker
pinned: false

AI Text Detector — FastAPI App Documentation

About

This FastAPI application predicts whether a given text is AI-generated or human-written based on a GPT-2 model.
It measures the perplexity of the input text to make the decision.

You can access the live version here:
Public App Link

API Endpoints

`GET /`

Description: Welcome route showing basic API information.

Response:

{
  "message": "FastAPI API is up.",
  "try": "/docs to test the API.",
  "status": "OK"
}

`GET /health`

Description: Health check to verify if the server is running.
Response:
```
{
  "status": "ok"
}
```

`POST /analyze`

Description: Analyze input text to determine if it is AI-generated or human-written.
Authorization: Requires Bearer Token.
Request Body:
```
{
  "text": "Enter your text here"
}
```

Response:

{
  "result": "AI-generated" | "Probably AI-generated" | "Human-written",
  "perplexity": 47.35
}

Important:
- Input text must contain at least two words.
- Without a valid token, this endpoint will not work.

Authorization Guide

Open /docs (Swagger UI).
Click the "Authorize" button at the top right.
Paste your Bearer Token into the Authorization field.
After authorization, you can use the /analyze endpoint.

Example Authorization header:

Authorization: Bearer YOUR_SECRET_TOKEN

How the AI Detection Works

The app loads a fine-tuned GPT-2 model at startup.
It calculates the perplexity of the input text:
- Perplexity less than 60 → AI-generated
- Perplexity between 60 and 80 → Probably AI-generated
- Perplexity greater than 80 → Human-written

Higher perplexity indicates the text is harder for the model to predict, usually meaning it is human-written.

How to Run Locally

Clone the repository:

git clone https://huggingface.co/spaces/can-org/canspace
cd canspace

Install dependencies:
```
pip install -r requirements.txt
```
Start the server:
```
uvicorn app:app --reload
```
Open the API docs at:
http://localhost:8000/docs

Quick Reminders

Always authorize first in /docs before using /analyze.
Text input must contain more than two words.
Public live app is available at: https://can-org-canspace.hf.space