sasy-guard

The SASY policy-enforcement runtime for Claude Code, distributed as a platform-specific wheel. uv tool install sasy-guard puts the prebuilt binaries on your machine — no need to clone the SASY repo or install a build toolchain.

This is the runtime (the binaries you run), distinct from the sasy package, which is the pure-Python SDK (a client library you import).

What's inside

The wheel for your OS/arch vendors three binaries:

• sasy — the (restricted) policy engine
• sasy-watch — the enforcement daemon: reconstructs the message-dependency graph from Claude Code's transcript and runs the policy check
• sasy-hook — the native, fail-closed PreToolUse hook (~2 ms)

plus the policy profiles and the SessionStart/PostToolUse/SessionEnd scripts.

Install & enable

uv tool install sasy-guard                          # 1. the runtime (binaries vendored)
sasy-guard install                                  # 2. binaries → ~/.sasy/bin + policy config
claude plugin marketplace add sasy-labs/sasy-demo   # 3. add the marketplace
claude plugin install sasy-guard                    #    install the hooks (standard way)

Then run claude — every tool call is checked against the security policy; denials surface a [SASY] … reason the agent relays.

• Select rule groups: sasy-guard install --rule-off a,b (drop) / --rule-on a,b (opt-in).
• Inspect the install: sasy-guard doctor.
• No-marketplace alternative: sasy-guard enable [project] writes the hooks straight into <project>/.claude/settings.json instead.

Building (maintainers)

Wheels are built per platform by CI and assembled with build-wheel.sh, which injects the binaries, syncs the profiles/scripts from plugins/sasy-guard, and retags the wheel for the current platform. See make sasy-guard-wheel and make sasy-guard-publish.