Text and conversations
For Gemini-native streaming, use
:streamGenerateContent. For the other text endpoints, set stream: true.
Use full creator-prefixed IDs such as anthropic/claude-sonnet-4-5 across formats. Messages also accepts bare Anthropic IDs; Gemini-native accepts bare Google IDs. Those conveniences do not add models outside the catalog.
The OpenAI SDK appends the endpoint to a base URL ending in
/v1. The Anthropic SDK appends /v1/messages itself, so its base URL must end at the hostname. See SDK configuration.Other inputs and outputs
Use
output_modality, input_modalities, and endpoints in model discovery. Sending an image-output model to Chat Completions does not generate an image; use its dedicated endpoint.
Conversation state and tools
Keep conversation history in your application and resend the relevant turns with each request. The gateway’s Responses endpoint does not implement stored-response retrieval orprevious_response_id chaining. Do not rely on store to persist a conversation. Request logs are observability records, not conversation state.
Function tools are relayed to your application for execution. Tool schemas and result formats differ between Chat Completions, Responses, and Messages. A tool result may carry an image on all three surfaces, as an inline data: base64 URI — see images in tool results. Responses also supports provider-executed search for supported xAI models; see provider-executed search.
Parameters and portability
- Reasoning controls translate to the selected model’s supported controls. Their effect varies by model.
- Prompt caching depends on the provider and prefix. A cacheable request is not a guaranteed hit.
- Models may reject sampling settings such as
temperatureor unsupported tool and input types. Test the exact model and request you intend to ship. - Do not assume OpenAI
response_formator Responsestext.formatprovides structured-output enforcement here; those controls are not part of the documented gateway contract. Validate generated data in your application. - Gateway-specific routing parameters from other services are not portable. Follow routing and failover for this gateway’s behavior.

