watchlight-engine

The in-process authorization engine behind Watchlight Developer Edition.

watchlight-engine lets a Python agent make a real authorization decision — ALLOW / DENY — for a tool call, in-process, with zero infrastructure: no database, no network, no sidecar. It ships as a prebuilt, self-contained compiled wheel.

Most developers want the watchlight package, the Developer Edition with an ergonomic decorator API. This watchlight-engine package is the lower-level engine it embeds — install it directly only if you are building on the engine yourself.

Install

pip install watchlight-engine

Prebuilt wheels are provided for Linux (x86_64, aarch64), macOS (Apple Silicon and Intel), and Windows (x64), for CPython 3.9 and newer. No Rust toolchain is required.

Quickstart

import watchlight_engine

engine = watchlight_engine.PolicyEngine()
assert engine.ready()

# Load a policy, then authorize a request — a real decision, in-process.
engine.add_policy(policy_json)
decision = engine.authorize(request_json)
print(decision)   # -> Allow / Deny with the governing reason

See the Watchlight documentation for policy and request shapes, and the Developer Edition guide for the full workflow.

What you get

• A real, in-process policy decision — the same authorization engine that powers the Watchlight platform, embedded so you can enforce governance without standing up any services.
• Fail-closed by design: ambiguity denies.
• A single prebuilt wheel per platform — install and go.

Developer Edition vs. Enterprise

The Developer Edition is for building and evaluating locally. The full Watchlight platform adds the governed control plane — centralized policy, tamper-evident lineage and audit, runtime enforcement across your fleet, drift and anomaly detection, secrets brokering, and the operator dashboard. See watchlight.ai to learn more.

License

Proprietary — licensed software, not open source. Copyright © Watchlight AI, LLC. All rights reserved.

The Developer Edition license lets you install and use watchlight-engine free of charge, including in production and commercially. A commercial license is required only to provide the engine itself to third parties as a hosted, managed, or embedded authorization service — contact legal@watchlight.ai. Redistribution, reverse-engineering, and sublicensing are not permitted. See the bundled LICENSE for the full terms.