prempti

What it is

Prempti (Falco Security, "experimental preview") is a cooperative policy-and-visibility layer for AI coding agents. The existing summary covers its features; the page's actionable content is its explicit threat model, its install/migration constraints, and platform-specific gotchas.

Trust model — the reason to read before acting

The page is emphatic that this is not a security boundary. Guardrails work because the agent cooperates: on a deny or ask verdict the agent receives an "LLM-friendly explanation" and adapts. Prempti explicitly states it "does not contain a determined adversarial agent" and is "not a sandbox, OS-level security, or a substitute for least-privilege environments or system hardening." It is meant to run alongside sandboxing and containment, not replace them. If your threat model includes a compromised or adversarial agent, this tool does not address it.

Preconditions / migration constraint

• If you already run coding-agents-kit: Prempti does not migrate or remove it. Uninstall coding-agents-kit first, or you get duplicate services and stale Claude Code hooks.
• Cross-platform: Linux, macOS, Windows on x86_64 and aarch64.

What to do

Install per platform. macOS (universal .pkg), scripted/non-interactive:

installer -pkg prempti-<version>-darwin-universal.pkg \
          -target CurrentUserHomeDirectory

Binaries are not code-signed — Gatekeeper may block them on first run. Allow via System Settings > Privacy & Security, or clear quarantine across the whole tree (both bin/ executables and the share/ plugin library can be flagged):

xattr -dr com.apple.quarantine ~/.prempti

Linux (installs to ~/.prempti/, starts a systemd user service, registers the hook):

tar xzf prempti-<version>-linux-x86_64.tar.gz
cd prempti-<version>-linux-x86_64
bash install.sh

Windows: run the MSI matching your CPU — prempti-<version>-windows-x64.msi (Intel/AMD64) or prempti-<version>-windows-arm64.msi (ARM64). The x64 MSI runs under emulation on ARM64 but the native ARM64 build is preferred.

Verify:

~/.prempti/bin/premptictl status
~/.prempti/bin/premptictl hook status
~/.prempti/bin/premptictl health

Switch enforcement level at any time with premptictl mode <guardrails|monitor> — monitor evaluates and logs rules without acting on the agent, useful for rule tuning before enforcing.

Caveats

Early preview: interfaces and behavior may change between releases. Unsigned binaries mean OS integrity/notarization checks will flag it. As above, it is a cooperative layer, not containment.