# Overflow
URL: https://docs.munito.ai/features/overflow

<Callout type="idea">Overflow is off by default, and Munito AI never uses it without your permission.</Callout>

When the capacity for a model is full, Munito AI answers with `503 Service Overloaded`. With overflow, Munito AI can answer the request with the same model at a vetted provider, or with another model.

Opt in for a request with the `munito-overflow` header:

| Value   | What can answer                               |
| ------- | --------------------------------------------- |
| `off`   | Nothing. This is the default.                 |
| `model` | The same model, at a provider in your region. |
| `class` | Also a similar model.                         |
| `any`   | Also any other model.                         |

The request keeps its region, zero data retention, and the price of the model that you asked for. When overflow answers, the response carries the `munito-overflow` header, and its `model` field names the model that answered.

Overflow applies to Chat Completions, Messages and Responses, except on the free tier and for flex and background requests.