Claude Code Security Plugin Sasy-Guard Released

The existing Claude Code security approach, PreToolUse hook, has a limitation in that its stateless nature prevents it from tracking the provenance of data. For example, it is difficult to block an attempt where an agent reads a .env file and then tries to leak that information to an external network.

The newly released Sasy-Guard provides the following technical features to solve this problem:

• Datalog-based policy engine: Compiles security policies written in natural language into Soufflé Datalog rules to perform deterministic and fast verification.
• Session dependency graph: Reconstructs the agent's entire session as a dependency graph to determine the provenance of the data each tool call originated from.
• State-based security: Beyond simply inspecting the current action, it logically infers and blocks security threats (e.g., unreviewed large-scale code pushes, sensitive information leaks) based on the history of previous operations.

Sasy-Guard is an open-source plugin that can be easily installed via the uv tool install sasy-guard command.