API reference

All endpoints under https://api.nxioai.com/api/v1. The machine-readable OpenAPI 3.1 document is at https://platform.nxioai.com/openapi.json.

Endpoints

Method	Path	Auth	Description
POST	/chat/completions	key	OpenAI-compatible chat completion; stream: true for SSE.
GET	/models	—	Public model catalog with prices.
GET	/key	key	Current key: label, limit, usage, remaining.
GET	/credits	key	Account balance.
GET	/generation?id=	key	Stored usage and cost of one request.
POST	/messages	key	Anthropic Messages format is not supported. Call Claude models through POST /chat/completions with the same model ids.
POST	/responses	key	OpenAI Responses API pass-through (models tagged openai-response). Upstream id kept for previous_response_id; our id in X-Request-Id / nxio_request_id; usage gains cost.
POST	/embeddings	key	OpenAI-compatible embeddings: {model, input}. Billed on prompt_tokens at the model's input price; usage.cost in USD.

Header	Direction	Meaning
Authorization: Bearer <key>	request	Required on authenticated routes.
X-Title / X-NXIO-Title	request	Optional app name for analytics.
HTTP-Referer	request	Optional app URL for analytics.
X-Request-Id	response	NXIO request id; equals the response id.
Retry-After	response	Seconds to wait on 402 (in-flight budget) and 429.