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README.md

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+# AI Text Detector — FastAPI App Documentation
 
-Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
+## 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](https://can-org-canspace.hf.space)**
+
+---
+
+## API Endpoints
+
+### `GET /`
+- **Description**: Welcome route showing basic API information.
+- **Response**:
+  ```json
+  {
+    "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**:
+  ```json
+  {
+    "status": "ok"
+  }
+  ```
+
+### `POST /analyze`
+- **Description**: Analyze input text to determine if it is AI-generated or human-written.
+- **Authorization**: Requires Bearer Token.
+- **Request Body**:
+  ```json
+  {
+    "text": "Enter your text here"
+  }
+  ```
+- **Response**:
+  ```json
+  {
+    "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
+1. Clone the repository:
+   ```bash
+   git clone https://huggingface.co/spaces/can-org/canspace
+   cd canspace
+   ```
+
+2. Install dependencies:
+   ```bash
+   pip install -r requirements.txt
+   ```
+
+3. Start the server:
+   ```bash
+   uvicorn app:app --reload
+   ```
+
+4. Open the API docs at:  
+   [http://localhost:8000/docs](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](https://can-org-canspace.hf.space)