---
language:
  - en
license: llama2
base_model: codellama/CodeLlama-7b-instruct-hf
tags:
  - code
  - security
  - peft
  - lora
  - qlora
  - vulnerability-detection
  - api-security
  - causal-lm
datasets:
  - custom
pipeline_tag: text-generation
---

# API Security QLoRA — Code Llama 7B

A QLoRA fine-tuned adapter on top of **CodeLlama-7b-instruct-hf**, trained to detect security vulnerabilities in API endpoint source code. Given a raw code snippet, the model produces a structured analysis identifying vulnerability type, severity, CWE, and a remediated version of the code.

---

## Model Details

| Property | Value |
|---|---|
| **Base Model** | `codellama/CodeLlama-7b-instruct-hf` |
| **Fine-tuning Method** | QLoRA (4-bit NF4 quantization) |
| **LoRA Rank (r)** | 16 |
| **LoRA Alpha** | 32 |
| **LoRA Dropout** | 0.05 |
| **Target Modules** | `q_proj`, `k_proj`, `v_proj`, `o_proj` |
| **Task** | Causal LM / Code Security Analysis |
| **Training Steps** | 531 |
| **Training Hardware** | Google Colab T4 (16GB VRAM) |

---

## Training Data

Fine-tuned on a custom dataset of **10,000 API-specific vulnerability samples** (synthetic + augmented) covering 19 vulnerability types mapped to OWASP API Top 10.

### Language Distribution

| Language | Share | Frameworks |
|---|---|---|
| Python | 46% | Flask, FastAPI, Django |
| JavaScript | 25% | Express.js, NestJS |
| Java | 15% | Spring Boot |
| PHP / Go / Ruby / C# | 14% | Laravel, Gin, Rails, ASP.NET |

### Vulnerability Distribution

| Vulnerability | Samples | CWE |
|---|---|---|
| SQL Injection | 2,425 | CWE-89 |
| Mass Assignment | 1,307 | CWE-915 |
| Path Traversal | 943 | CWE-22 |
| IDOR | 860 | CWE-639 |
| Broken Authorization | 792 | CWE-285 |
| Command Injection | 600 | CWE-78 |

### Severity Breakdown

- **Critical (43%)**: RCE, SQLi, unauthorized admin access
- **High (41%)**: Data leaks, IDOR, authorization bypass
- **Medium / Clean (16%)**: XSS, input validation warnings, baseline clean samples

---

## Usage

```python
from transformers import AutoTokenizer, AutoModelForCausalLM
from peft import PeftModel
import torch

base_model_id = "codellama/CodeLlama-7b-instruct-hf"
adapter_id    = "harsharajkumar273/api-security-qlora"

tokenizer = AutoTokenizer.from_pretrained(adapter_id, use_fast=False)

base = AutoModelForCausalLM.from_pretrained(
    base_model_id,
    torch_dtype=torch.float16,
    device_map="auto",
)
model = PeftModel.from_pretrained(base, adapter_id)
model.eval()

code_snippet = """
@app.route('/user/<int:user_id>')
def get_user(user_id):
    query = f"SELECT * FROM users WHERE id = {user_id}"
    result = db.execute(query)
    return jsonify(result)
"""

prompt = f"[INST] Analyze this API endpoint for security vulnerabilities:\n\n{code_snippet} [/INST]"
inputs = tokenizer(prompt, return_tensors="pt").to(model.device)

with torch.no_grad():
    outputs = model.generate(**inputs, max_new_tokens=512, temperature=0.1)

print(tokenizer.decode(outputs[0], skip_special_tokens=True))
```

---

## Integration with API Security Scanner

This adapter is the default model in the [API Security Scanner](https://github.com/harsharajkumar/api-security) project. It is loaded automatically — no manual path configuration needed:

```bash
git clone https://github.com/harsharajkumar/api-security
cd api-security
pip install -r requirements.txt
streamlit run app.py
```

The scanner will download this adapter from the Hub on first run and cache it locally.

---

## Intended Use

- Automated API security auditing in CI/CD pipelines
- Developer tooling for identifying vulnerable endpoint patterns
- Security research and OWASP API Top 10 education

## Out of Scope

- General-purpose code generation
- Non-API code (UI components, data processing scripts, etc.)
- Production security decisions without human review

---

## Credits

Developed as part of **CS6380 — API Security Project**

**Authors:** Siddhanth Nilesh Jagtap · Tanuj Kenchannavar · Harsha Raj Kumar