WanAPIs Completions API

openapi: 3.2.0
info:
  title: WanAPIs Unified AI Completions API
  version: '2026-05-27'
  summary: OpenAI-compatible AI gateway aggregating GPT, Claude, Gemini, DeepSeek and other LLM, image, video, and audio model providers behind a single key.
  description: 'WanAPIs (https://wanapis.com) is a developer-focused AI API gateway. Clients

    issue OpenAI-style requests against `https://api.wanapis.com/v1`; the

    platform routes them to the appropriate upstream model provider (OpenAI,

    Anthropic, Google, DeepSeek, Moonshot, Alibaba, xAI, Mistral, Stability,

    Midjourney, etc.) and applies per-project quota, metering, channel

    routing, and failover.


    This OpenAPI is **hand-authored** by API Evangelist. WanAPIs publishes no

    machine-readable spec — `https://api.wanapis.com/openapi.json` returns the

    admin dashboard. Operations included here are taken from

    https://wanapis.com/docs and https://wanapis.com/pricing and reflect the

    OpenAI-compatible surface plus the documented WanAPIs `/responses` and

    async task patterns. Request and response schemas mirror the OpenAI HTTP

    API by convention; consult the upstream OpenAI reference for full field

    semantics.

    '
  termsOfService: https://wanapis.com/
  contact:
    name: WanAPIs Support
    email: support@wanapis.com
    url: https://wanapis.com/
  license:
    name: Proprietary
    url: https://wanapis.com/
servers:
- url: https://api.wanapis.com/v1
  description: WanAPIs production OpenAI-compatible base URL.
security:
- bearerAuth: []
tags:
- name: Completions
  description: Legacy text completions (OpenAI compatible).
paths:
  /completions:
    post:
      tags:
      - Completions
      operationId: createCompletion
      summary: Create a (legacy) text completion
      description: OpenAI-compatible legacy completions endpoint. Prefer `/chat/completions` for new development.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CompletionRequest'
      responses:
        '200':
          description: Completion result.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CompletionResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
        '500':
          $ref: '#/components/responses/UpstreamFailure'
components:
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    RateLimited:
      description: Rate limit or quota exceeded.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    UpstreamFailure:
      description: Upstream provider failure (500–504). Retry with exponential backoff; WanAPIs may auto-failover to a configured channel.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    CompletionResponse:
      type: object
      properties:
        id:
          type: string
        object:
          type: string
          const: text_completion
        created:
          type: integer
        model:
          type: string
        choices:
          type: array
          items:
            type: object
            properties:
              text:
                type: string
              index:
                type: integer
              finish_reason:
                type: string
        usage:
          $ref: '#/components/schemas/Usage'
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
            type:
              type: string
            code:
              type: string
            param:
              type: string
              nullable: true
    CompletionRequest:
      type: object
      required:
      - model
      - prompt
      properties:
        model:
          type: string
        prompt:
          oneOf:
          - type: string
          - type: array
            items:
              type: string
        max_tokens:
          type: integer
        temperature:
          type: number
        top_p:
          type: number
        n:
          type: integer
        stream:
          type: boolean
        stop:
          oneOf:
          - type: string
          - type: array
            items:
              type: string
    Usage:
      type: object
      properties:
        prompt_tokens:
          type: integer
        completion_tokens:
          type: integer
        total_tokens:
          type: integer
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API Key
      description: 'Authenticate every request with `Authorization: Bearer <wanapis_api_key>`.

        Keys are issued per project in the WanAPIs dashboard and may be scoped

        with quota and model availability.

        '