> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vence.one/llms.txt
> Use this file to discover all available pages before exploring further.

# Decision Engine

> Explainable underwrite and access decisions — verdict, limits, reasons, model and policy versions.

# Decision Engine

The Decision Engine turns Trust Graph context + Policy Engine rules into a **reproducible verdict**.

## What you get back

* Verdict (approve / review / decline — program-defined)
* Recommended limit or access tier
* Principal reasons (reason codes)
* Model version and policy version
* Conditions and monitoring hooks

## Design rules

* Same inputs + same policy version → same path
* Sandbox uses deterministic rules for demos and CI
* Live / production keys run decisions under your program’s compliance posture **when Vence enables live** for your org (live financial underwriting is gated)
* AI assists investigation; synchronous auth prefers deterministic policy

Call underwrite via the [API overview](/developers/api-overview) or follow the [underwrite guide](/guides/underwrite).