# Service tiers now available on AI Gateway

**Published:** July 21, 2026 | **Authors:** Walter Korman, Rohan Taneja, Jerilyn Zheng

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AI Gateway now supports service tiering. Service tiers let you optimize for latency, throughput, and cost per request to match your use case. Pick a faster tier for interactive workloads (less queueing, higher token throughput), or a lower cost tier for background jobs that can tolerate more latency.

At launch, service tiering is available for OpenAI and Gemini models.

[Service tiers](https://vercel.com/docs/ai-gateway/models-and-providers/service-tiers) work across every AI Gateway API format: [AI SDK](https://ai-sdk.dev), [Chat Completions API](https://vercel.com/docs/ai-gateway/sdks-and-apis/openai-chat-completions), [Anthropic Messages API](https://vercel.com/docs/ai-gateway/sdks-and-apis/anthropic-messages-api), [OpenAI Responses API](https://vercel.com/docs/ai-gateway/sdks-and-apis/responses), and [OpenResponses API](https://vercel.com/docs/ai-gateway/sdks-and-apis/openresponses). AI Gateway adjusts billing based on the tier each request used.

## Tiers

- `default`: Standard processing
- `priority`: Faster processing at increased cost
- `flex`: Lower cost with potentially higher latency

If a service tier is not specified, requests run on the default tier.

## Basic usage

Set `serviceTier` under `providerOptions.gateway`. The same option works across all models and providers that support service tiers, so you can swap the model without restructuring provider-specific options:

```tsx
import { generateText } from 'ai';

const { text, providerMetadata } = await generateText({
  model: 'openai/gpt-5.6-sol',
  prompt,
  providerOptions: {
    gateway: {
      serviceTier: 'priority',
    },
  },
});
```

The applied tier is returned in the provider metadata so you can confirm which tier served the request. This is useful when a priority request falls back to default capacity, or when comparing observed latency across tiers.

Service tier is serviced on a best-effort basis: if a tier can't be applied, the request runs on the default tier at the default rate, and only an invalid service tier value fails the request.

### Per-provider control

If a model can be served by multiple providers and you only want a service tier on some of them or to configure different service tiers across each, set the tier on the provider's own namespace instead.

```typescript
import { generateText } from 'ai';

const { text } = await generateText({
  model: 'google/gemini-3.6-flash',
  prompt,
  providerOptions: {
    vertex: {
      serviceTier: 'priority',
    }, // Other providers serving this model fall back to their default tier.
  },
});
```

## Pricing

AI Gateway applies per-tier rates automatically based on the tier each request actually used. If a `priority` request gets downgraded to default capacity, billing reflects the default rate, not the priority rate.

| **Tier** | `default` | `priority` | `flex` |
| **Cost relative to default** | Baseline | ~1.8-2x default pricing | ~0.5x default pricing |

More details about providers and tiering are in the [service tiers reference](https://vercel.com/docs/ai-gateway/models-and-providers/service-tiers).

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📚 **More updates:** [View all changelog entries](/changelog/sitemap.md) | [Blog](/blog/sitemap.md)