Models

Models are the AI systems that process your requests. You specify the model in each request body, and you can use an access key configuration to restrict which models an access key may call.

Specifying models

Model name only

{
  "model": "gpt-4o",
  "messages": [{"role": "user", "content": "Hello"}]
}

The gateway looks up gpt-4o in the model catalog and routes to OpenAI.

Provider prefix

{
  "model": "anthropic:claude-sonnet-4-6",
  "messages": [{"role": "user", "content": "Hello"}]
}

Use provider:model when you want to force a specific provider or target a model you run yourself.

Multiple models (failover)

List fallback models with the models array:

{
  "model": "gpt-4o",
  "models": ["gpt-4o-mini", "anthropic:claude-sonnet-4-6"],
  "messages": [{"role": "user", "content": "Hello"}]
}

The gateway tries model first, then each entry in models in order, until one succeeds.

Unknown models (pass-through)

If a model is not in the catalog, the gateway still routes it when you include a provider prefix:

{
  "model": "openai:some-new-model",
  "messages": [{"role": "user", "content": "Hello"}]
}

The provider returns an error if the model does not exist. Pass-through models must still be allowed by the access key’s configuration.

Model and provider names

Model names are not case-sensitive: gpt-4o, GPT-4o, and Gpt-4O all resolve to the same model. Provider names are matched exactly, so use the lowercase Provider ID from the model catalog. Name models and providers by their primary catalog ID. The gateway does not resolve alternate names for either.

Model capabilities

Models differ in input/output modalities, context window, and features. See the model catalog for details.

Next steps

Model catalog: Supported models by provider
Choose a model: Model IDs and provider prefixes
Configure fallback models: Try another model when the first one fails
Restrict providers and models: Limit models per key

Concepts

Getting Started With

SDKs

Guides

Observability

Examples

Reference

API Reference

Specifying models

Model name only

Provider prefix

Multiple models (failover)

Unknown models (pass-through)

Model and provider names

Model capabilities

Next steps

​Specifying models

​Model name only

​Provider prefix

​Multiple models (failover)

​Unknown models (pass-through)

​Model and provider names

​Model capabilities

​Next steps

Specifying models

Model name only

Provider prefix

Multiple models (failover)

Unknown models (pass-through)

Model and provider names

Model capabilities

Next steps