# What is an AI gateway?

> An AI gateway is a service between your application and AI model providers. Your code calls one API with one key; the gateway chooses the model and provider, retries elsewhere when a provider fails, applies your budgets and rules, and records what each request cost.

Source: https://digitspace.ai/learn/what-is-an-ai-gateway · Last checked: 2026-10-30

## Without and with a gateway

**Calling providers directly:**
- A key, an SDK and a bill per provider
- Fallback code written by you
- Spend spread across dashboards
- Rules enforced in your app

**Through a gateway:**
- One key, one API, one bill
- Failover handled for you
- Every request costed in one place
- Budgets and rules per key

## What a gateway usually does

- **Unified API:** One request format for every model, usually OpenAI's Chat Completions.
- **Routing:** Choosing the model, or the provider for a model, for each request.
- **Failover:** Moving a request to another provider when one times out or errors.
- **Cost and usage tracking:** Tokens, price and latency for every request.
- **Governance:** Budgets, allowed models, guardrails, roles and audit logs.

## Hosted or self-hosted

|  | Hosted (like DigitSpace) | Self-hosted proxy |
| --- | --- | --- |
| Set-up | Sign up and change a URL | Deploy and run a service |
| Provider keys | The gateway's credits, or your own | Your own |
| Upgrades and uptime | The gateway's job | Yours |
| Data path | Through the gateway's servers | Through yours |

## When you need one

You probably don't need a gateway for one prototype on one model. You start to need one when you use more than one provider, when an outage would hurt, when several people or features share a bill, or when you have to prove where requests went.

## Questions

### Is an AI gateway the same as an API gateway?

It's a specialised one: on top of routing traffic it understands models, tokens, prices and provider health.

### Does a gateway add latency?

A well-built one adds very little, since routing is decided in memory before the call. Most time is the model generating its answer.

### Does it change model output?

No. The model's answer is passed back as it is; the gateway only changes which model or provider answers.

## Related

- [How it works](https://digitspace.ai/how-it-works)
- [LLM routing, explained](https://digitspace.ai/learn/llm-routing)
- [LLM API failover](https://digitspace.ai/learn/llm-failover)
- [Comparisons](https://digitspace.ai/compare)

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