CAMERA: Adapting to Semantic Camouflage in Unsupervised Text Attributed Graph Fraud Detection

May 19, 2026 ยท View on GitHub

This is the official implementation of the following paper: CAMERA: Adapting to Semantic Camouflage in Unsupervised Text Attributed Graph Fraud Detection, Accepted by IJCAI 2026

CAMERA employs a mixture of expert architectures to disentangle structural, statistical, and semantic signals, enabling robust anomaly detection under distribution shift without relying on labeled data.

Environment

Python 3.11

  • torch==2.5.1+cu121
  • torch-sparse==0.6.18+pt25cu121
  • numpy==1.26.4
  • scikit-learn==1.6.1
  • pickle
  • sentence-transformers==3.3.1
  • torch-geometric==2.6.1

Usage

Step 0: Set up the dataset

You can download the dataset points from: https://drive.google.com/file/d/1z75C7Cul7z4SYNhyZn6Jit7cY18xFbEA/view?usp=sharing

To make experimentation easier and reduce reproduction costs, we also provide text encodings generated using the OpenAI encoding model, available at: https://drive.google.com/file/d/1PqaIm_m3DVZbjdoe8NIuMupik3rtJO42/view?usp=sharing

Step 1 Text Encoding

First, generate text embeddings for each dataset.

python text_encoder.py

Step 2 Run CAMERA

After text embeddings are prepared, run the main training and evaluation script with dataset specific hyperparameters.

Below are the hyperparameter settings used in our experiments.

Reddit

python run.py --dataset_name reddit --epochs 1200 --alpha 5.0 --beta 0.1 --lr 1e-3

Instagram

python run.py --dataset_name instagram --epochs 15 --alpha 10.0 --beta 10.0 --lr 5e-5

Amazon

python run.py --dataset_name amazon --epochs 15 --alpha 0.1 --beta 1.0 --lr 5e-5

YelpChi

python run.py --dataset_name yelpchi --epochs 450 --alpha 0.1 --beta 10.0 --lr 1e-3

Citation

If you find our repository useful for your research, please consider citing our paper:

@inproceedings{pan2026CAMERA,
  title={CAMERA: Adapting to Semantic Camouflage in Unsupervised Text-Attributed Graph Fraud Detection},
  author={Pan, Junjun and Liu, Yixin and Zheng, Yu and Chi, Lianhua and Liew, Alan Wee-Chung and Pan, Shirui},
  booktitle={International Joint Conference on Artificial Intelligence},
  year={2026}
}