Nscale

Nscale Chat Completions API

OpenAI-compatible chat completions.

Documentation GitHub OpenAPI

Operations 1

POST /chat/completions Create a chat completion #

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this

find_apisBrowse and filter every API in the catalog.
get_api_artifactsOne API's artifacts, grouped by type.
get_openapiThe primary OpenAPI for this API.
find_similar_apisAPIs that look like this one.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This API

curl "https://apis.io/api/v1/apis/nscale:nscale-chat-completions-api"

All apis

curl "https://apis.io/api/v1/apis?limit=25"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

openapi: 3.2.0
info:
  title: Nscale Serverless Inference Chat API
  description: OpenAI-compatible serverless inference API for Nscale. Provides chat completions, text completions, embeddings, image generation, and model discovery against open models (Llama, Qwen, DeepSeek, GPT OSS, Mistral, Flux) served on Nscale GPU infrastructure. Authenticate with a Bearer API key issued from the Nscale console.
  termsOfService: https://www.nscale.com/legal/terms-of-service
  contact:
    name: Nscale Support
    url: https://docs.nscale.com
  version: '1.0'
servers:
- url: https://inference.api.nscale.com/v1
  description: Serverless Inference API
security:
- bearerAuth: []
tags:
- name: Chat Completions
  description: OpenAI-compatible chat completions.
paths:
  /chat/completions:
    post:
      operationId: createChatCompletion
      tags:
      - Chat Completions
      summary: Create a chat completion
      description: Generates a chat completion response for the provided model and chat history. Supports streaming via Server-Sent Events when stream is true.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ChatCompletionRequest'
      responses:
        '200':
          description: A chat completion (or an SSE stream when stream=true).
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ChatCompletionResponse'
            text/event-stream:
              schema:
                type: string
                description: Server-Sent Events stream of ChatCompletionChunk objects.
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
components:
  schemas:
    ChatCompletionResponse:
      type: object
      properties:
        id:
          type: string
        object:
          type: string
          example: chat.completion
        created:
          type: integer
        model:
          type: string
        choices:
          type: array
          items:
            type: object
            properties:
              index:
                type: integer
              message:
                $ref: '#/components/schemas/ChatMessage'
              finish_reason:
                type: string
        usage:
          $ref: '#/components/schemas/Usage'
    ChatMessage:
      type: object
      required:
      - role
      - content
      properties:
        role:
          type: string
          enum:
          - system
          - user
          - assistant
          - tool
        content:
          description: Text content or an array of multimodal content parts.
          oneOf:
          - type: string
          - type: array
            items:
              type: object
        name:
          type: string
    ChatCompletionRequest:
      type: object
      required:
      - model
      - messages
      properties:
        model:
          type: string
          description: Model identifier, e.g. meta-llama/Llama-4-Scout-17B-16E-Instruct.
        messages:
          type: array
          items:
            $ref: '#/components/schemas/ChatMessage'
        temperature:
          type: number
          format: float
          minimum: 0
          maximum: 2
          default: 1
        top_p:
          type: number
          format: float
          minimum: 0
          maximum: 1
          default: 1
        max_tokens:
          type: integer
          description: Maximum number of tokens to generate.
        stream:
          type: boolean
          default: false
          description: If true, partial deltas are sent as Server-Sent Events.
        stop:
          oneOf:
          - type: string
          - type: array
            items:
              type: string
        frequency_penalty:
          type: number
          format: float
          minimum: -2
          maximum: 2
          default: 0
        presence_penalty:
          type: number
          format: float
          minimum: -2
          maximum: 2
          default: 0
        tools:
          type: array
          items:
            type: object
        tool_choice:
          oneOf:
          - type: string
          - type: object
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
            type:
              type: string
            code:
              type: string
    Usage:
      type: object
      properties:
        prompt_tokens:
          type: integer
        completion_tokens:
          type: integer
        total_tokens:
          type: integer
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    RateLimited:
      description: Too many requests; back off and retry.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'Nscale API key issued from the console, sent as `Authorization: Bearer $NSCALE_API_KEY`.'