> ## Documentation Index
> Fetch the complete documentation index at: https://ngrok.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Choose how to reach providers

> Decide whether to use credits, bring your own provider key, or connect a model you run yourself.

The AI Gateway can reach providers in three ways. Pick the path that matches what you're trying to do.

## Use OpenAI or Anthropic without a provider account

Use [credits](/ai-gateway/concepts/credits) when you want the fastest path to OpenAI or Anthropic. The gateway supplies upstream credentials and bills model usage through your credit balance.

Start here: [Use ngrok.ai inference](/ai-gateway/guides/use-ngrok-ai-inference).

## Bring your own provider key

Bring your own key when you want upstream usage billed to your provider account, need a provider that requires your own credentials, or want to use your own OpenAI or Anthropic account.

Start here: [Bring your own provider key](/ai-gateway/guides/attaching-provider-keys).

## Use a model you run yourself

Use a custom provider when your model runs on your machine, private network, cloud GPU, or another OpenAI- or Anthropic-compatible endpoint outside the built-in catalog.

Start here: [Use a model you run yourself](/ai-gateway/guides/use-a-model-you-run-yourself).

## Make the provider usable from a request

Adding a provider or provider key doesn't route traffic by itself. A working request needs:

1. A provider: built-in or custom.
2. A credential source: credits or a provider key, when required.
3. An [access key configuration](/ai-gateway/guides/access-key-configurations) that allows the provider and model.
4. An [access key](/ai-gateway/concepts/access-keys) assigned to that configuration.
5. A request with a matching `model` or `provider:model`.

If requests are rejected before they reach the provider, check [Restrict providers and models](/ai-gateway/guides/restrict-providers-and-models).

## Next steps

* [Choose a model](/ai-gateway/guides/model-selection-strategies): Use model IDs in requests
* [Access key configurations](/ai-gateway/guides/access-key-configurations): Scope access and choose credentials
* [Model catalog](/ai-gateway/reference/model-catalog): Check providers, models, aliases, and key requirements