openapi: 3.0.1
info:
  title: Featherless AI Chat Models API
  description: OpenAI-compatible REST API for the Featherless AI serverless inference platform. A single Bearer-authenticated interface serves thousands of open-weight Hugging Face models for chat completions, legacy text completions, embeddings, and model discovery. Pricing is a flat monthly subscription with unlimited tokens rather than per-token billing.
  termsOfService: https://featherless.ai/terms
  contact:
    name: Featherless AI Support
    url: https://featherless.ai
  version: '1.0'
servers:
- url: https://api.featherless.ai/v1
  description: OpenAI-compatible base URL for Featherless AI inference.
security:
- bearerAuth: []
tags:
- name: Models
  description: Model catalog discovery.
paths:
  /models:
    get:
      operationId: listModels
      tags:
      - Models
      summary: List models
      description: Lists the open-weight models available for serverless inference on Featherless AI. OpenAI compatible.
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ListModelsResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    Model:
      type: object
      properties:
        id:
          type: string
          description: Model identifier.
        object:
          type: string
          enum:
          - model
        created:
          type: integer
        owned_by:
          type: string
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
            type:
              type: string
            code:
              type: string
              nullable: true
    ListModelsResponse:
      type: object
      properties:
        object:
          type: string
          enum:
          - list
        data:
          type: array
          items:
            $ref: '#/components/schemas/Model'
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: Featherless API key
      description: 'Set `Authorization: Bearer <FEATHERLESS_API_KEY>`. Keys are created in the Featherless dashboard.'