OpenAI Responses API subset on a PopNow text model

Accepts the stateless subset of the OpenAI Responses API: model, input (string or item array with message, function_call and function_call_output items), instructions, max_output_tokens, temperature, top_p, tools (function tools), tool_choice, text.format, reasoning.effort and stream. The request is translated to a chat completion internally. previous_response_id is rejected with 400; send the full history in input instead. As on Chat Completions, sampling parameters the model does not declare are ignored and listed in the X-PopNow-Ignored-Params response header, and values outside the model's range or levels are changed to the nearest accepted value and listed in X-PopNow-Adjusted-Params.

Non-streaming calls return a response object with output[] (message and function_call items) and usage. Streaming calls emit response.created, response.output_text.delta and response.completed events.

Billing: chat models are priced per token in credits (1 credit = $0.001), listed per 1M input and output tokens in credits on GET /api/v1/models and GET /v1/models. When the request is accepted, the most it can cost is held from your balance, computed from the input and max_tokens (the model's maximum output when you omit it, so set max_tokens to keep holds small). When the reply ends you are charged its actual usage in fractional credits, with no per-request minimum, and the rest of the hold is released. A balance below the hold, or a key spend limit that would be exceeded, returns 402 before anything is sent to the model. A request that fails or that the model refuses is refunded in full. The X-PopNow-Task-Id response header names the task; GET /api/v1/jobs/recordInfo shows the final charge in cost (USD) and exactCredits. Message text is not kept after the charge settles. Requests are forwarded to the model as sent and each model's own usage policy applies.