Hermes Katana is a security toolkit for Large Language Model (LLM) agents, developed by claudlos. The project, written in Python, provides a multi-layered security approach. Key features include character-level taint tracking, which monitors the origin of text throughout an agent's operations, and a proxy secret guard to prevent sensitive information leakage. It also incorporates a policy engine that evaluates tool calls based on defined rules, and a red-team benchmarking suite for testing attack effectiveness.
The toolkit's latest release, v3.0.0, introduces production middleware profiles (`fast_cpu`, `balanced`, `max`) and a fast CPU Scabbard profile utilizing a distilled v15 MiniLM ONNX runtime. The default `ScabbardConfig.block_threshold` has been lowered from 0.7 to 0.5 to improve attack detection. The release also includes significant Windows portability fixes, addressing issues related to encoding, subprocess handling, and file paths, ensuring broader compatibility. Hermes Katana is available via `pip install hermes-katana` and includes a visual manual for setup and operations.