# Modes of Operation

The Lineaje GOS Artifactory Proxy ships with two operating modes, allowing teams to adopt it incrementally without disrupting existing delivery pipelines. 

## Enforce Mode 

In Enforce mode, the proxy strictly blocks the download of any package that does not meet the GOS criteria or fails a custom policy check. The build receives an HTTP 4XX error response and the download is stopped. This is the recommended steady-state operating mode for production build pipelines where supply chain integrity is non-negotiable. 

* Build fails fast when a non-gold dependency is requested 
* Stops unsafe code before it can be compiled, tested, or deployed 
* Provides an immutable audit trail of every blocked attempt 
* Policy violation details are logged to the Lineaje platform and surfaced in build output 

## Observe Mode 

In Observe mode, all artifact downloads are permitted regardless of GOS status or policy violations. However, every non-compliant download is recorded, classified, and reported on the Lineaje GOS dashboard. Observe mode is ideal for: 

* Initial onboarding and baselining — understand your current open source risk posture before enforcing 
* Teams that need visibility without yet committing to hard enforcement 
* Audit and compliance reporting without disrupting existing build pipelines 
* Gradually building the organizational muscle to move toward Enforce mode 

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Observe mode does not prevent unsafe packages from entering your build. It is a transitional tool. Lineaje recommends transitioning to Enforce mode within 90 days of initial deployment. 
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