# Faults and proxying

> Mock selected behavior, proxy unmatched traffic, and make latency or upstream failures explicit.

- Canonical URL: https://dotmock.com/docs/features/proxy-mode
- Capability status: Available
- Last verified: 2026-07-24

## Prerequisites
- A DotMock workspace you can access
- The API ID in $API_ID and its published runtime URL in $MOCK_URL when the example calls the mock

## In this guide
- Understand the routing decision
- Set one trusted upstream
- Know what is forwarded
- Make proxy failure explicit in tests
- Dry-run never contacts the upstream

## Verified boundaries
- Dry-runs never contact the upstream. Live proxying requires an explicitly configured trusted target.

Read the canonical guide for its complete examples and expected results: https://dotmock.com/docs/features/proxy-mode