## Vercel AI Gateway

[Vercel AI Gateway](/content/docs/ai-gateway/index.html) now supports [routing rules](/content/docs/ai-gateway/models-and-providers/routing-rules/index.html).

Routing rules are firewall-style rules that control which models your team can use, applied at the gateway level instead of in your application code.

When a model goes down or gets retired, you usually have to ship a code change to move off it. With routing rules, you push one rule and every request reroutes instantly. There are two types:

|     |     |     |
| --- | --- | --- |
| **Type** | **What it does** | **Use it to** |
| **Rewrite** | Serves a request for one model using another | Keep traffic flowing when a model is unavailable, migrate off a retired model, standardize on one model, or route an expensive model to a cheaper one |
| **Deny** | Blocks requests for a model | Keep your team off models you haven’t approved |

Rules apply to every request made with your team's AI Gateway credentials. You manage them with the [Vercel CLI](/content/docs/ai-gateway/models-and-providers/routing-rules#manage-rules-with-the-cli/index.html).

### Rewrite

Create a rewrite with a source and a destination model. The Gateway swaps in the destination transparently, so your application keeps requesting the source model:

```bash
vercel ai-gateway rules add --type rewrite \
  
  --source anthropic/claude-opus-4.8 \
  
  --destination anthropic/claude-haiku-4.5
```

### Deny

Create a deny rule to block a model. Requests for it return a `403`:

```bash
vercel ai-gateway rules add --type deny --source openai/gpt-5.5
```

Rules only change which model serves a request. Everything else you’ve configured still applies to the destination model, including:

- **Request-level**: [BYOK](/content/docs/ai-gateway/authentication-and-byok/byok/index.html), [model fallbacks](/content/docs/ai-gateway/models-and-providers/model-fallbacks/index.html), [sorting](/content/docs/ai-gateway/models-and-providers/provider-filtering-and-ordering/index.html), the `only` [filter](/content/docs/ai-gateway/models-and-providers/provider-filtering-and-ordering/index.html), and [provider options](/content/docs/ai-gateway/models-and-providers/provider-options/index.html).

- **Team-level**: [Zero Data Retention](/content/docs/ai-gateway/security-and-compliance/zdr/index.html) and the [provider allowlist](/content/docs/ai-gateway/security-and-compliance/provider-allowlist/index.html).

Routing rules are in beta. For more information, read the [routing rules docs](/content/docs/ai-gateway/models-and-providers/routing-rules/index.html).