> ## Documentation Index
> Fetch the complete documentation index at: https://neuraltrust-92b43583-develop.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Fallback

> Retry across registries when an upstream fails — configure the ordered chain and triggers on the consumer Routing tab.

**Fallback** turns a single upstream failure into a retry on the next registry instead of
an error to the client. Configure it per [consumer](/trustgate/concepts/consumers) on the
**Routing** tab when **Strategy** is **Fallback** (or when fallback is enabled alongside
your routing setup).

## Configure fallback in the UI

1. Open **Consumers** → select a consumer → **Routing**.
2. Set **Strategy** to **Fallback** (under **Direct**).
3. Build the **chain** — the ordered list of registries to try.
4. Choose **triggers** (which failures start a retry) and optional **budget** (max attempts
   / total latency).
5. Save.

## Triggers

A retry only happens when the failure matches a configured trigger:

| Trigger          | Fires on                       |
| ---------------- | ------------------------------ |
| HTTP 5xx         | Upstream 5xx responses.        |
| HTTP 429         | Upstream rate-limit responses. |
| Timeout          | Upstream timeouts.             |
| Provider error   | Provider-reported errors.      |
| Plugin rejection | A policy rejected the request. |

## Budget

The budget caps how hard TrustGate tries:

* **Max attempts** — total forward attempts (including the first).
* **Max total latency** — wall-clock ceiling across all attempts.

When either limit is reached, the last error is returned to the client.

## The chain

The chain is the ordered list of registries to try. On each failure TrustGate moves to the
next entry and does not re-pick an already-failed registry within the same request.

> Use fallback to span providers (for example OpenAI → Azure OpenAI → Bedrock) for
> resilience, or to degrade from a premium model to a cheaper one under load.

See also [Load balancing](/trustgate/routing/load-balancing),
[Smart routing](/trustgate/routing/smart-routing), and
[Model resolution](/trustgate/routing/model-resolution).