OpenAI

Official positioning

OpenAI's developer platform spans general text and reasoning, code, vision, image generation, video, speech and realtime interaction, embeddings, and moderation. The official model catalog is the authoritative source for model IDs, modalities, and lifecycle status; resources from the same provider do not automatically share request fields.

Prefer Responses for new projects

OpenAI recommends Responses API for all new projects. Chat Completions remains supported for existing messages and choices integrations. Responses uses input and typed output items, so a migration must update response parsing rather than changing only the URL.

Direct versus gateway authentication

Direct OpenAI calls use the OpenAI base URL, an OpenAI-issued API key, and Authorization: Bearer. This site also recommends a Bearer header, but requires this site's base URL, a site-issued key, and the exact marketplace model ID. The credentials are not interchangeable, and the gateway guarantees only endpoints explicitly listed by its protocol guide and marketplace.

Tools, streaming, and response reading

A custom-function loop requires the application to validate arguments, execute the tool, return its result, and continue the model call. Responses and Chat use different SSE event shapes; parse complete typed events rather than arbitrary network chunks. Whether streaming usage appears or needs an explicit option must be verified per endpoint and channel.

Workloads and production checks

OpenAI models fit structured output, advanced reasoning, code generation, multimodal understanding, tool workflows, and realtime voice. Evaluate quality, latency, and cost on real tasks, then verify snapshots, context, output limits, tools, rate limits, geography, data controls, and deprecation dates before production.