OpenAI Responses

GPT models support the OpenAI-compatible Responses API at POST /v1/responses. Use input for prompts or structured content and read generated items from output.

curl https://api.sandbase.ai/v1/responses \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/<gpt-model>",
    "input": "Explain immutable infrastructure in one sentence."
  }'

Chat Completions compatibility

The same GPT models also support POST /v1/chat/completions. That protocol uses messages in the request and choices in the response, while Responses uses input and output. The parameter envelopes are not interchangeable; choose the endpoint that matches your SDK.

See Chat Completions for the compatible request format and GPT model references for model-specific fields and limits.

Next steps

• Responses API reference
• Chat Completions API reference
• Supported Models