openapi.yaml

openapi: 3.0.0
info:
  title: OneLLM.dev API
  version: 1.0.0
  description: This is the official API documentation for OneLLM.dev.
servers:
  - url: https://onellm.dev
    description: Main API server
paths:
  /v1/chat/completions:
    post:
      summary: Send a chat request to a large language model.
      description: Send a chat request to one of the supported large language models.
      operationId: chatCompletions
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                endpoint:
                  type: string
                  example: /v1/chat/completions
                model:
                  type: string
                  enum:
                    - GPT-4.1
                    - GPT-4.1-Mini
                    - GPT-4.1-Nano
                    - GPT-o3
                    - GPT-o4-mini
                    - Opus-4
                    - Sonnet-4
                    - Haiku-3.5
                    - Opus-3
                    - Sonnet-3.7
                    - Haiku-3
                    - DeepSeek-Reasoner
                    - DeepSeek-Chat
                    - 2.5-Flash-preview
                    - 2.5-Pro-preview
                    - 2.0-Flash
                    - 2.0-Flash-lite
                    - 1.5-Flash
                    - 1.5-Flash-8B
                    - 1.5-Pro
                temperature:
                  type: number
                  format: float
                  example: 0.7
                stream:
                  type: boolean
                  example: true
                messages:
                  type: array
                  items:
                    type: object
                    properties:
                      role:
                        type: string
                        enum: [user, assistant]
                      content:
                        type: string
                max_tokens:
                  type: integer
                  example: 256
                top_p:
                  type: number
                  format: float
                  example: 0.95
                stop_sequences:
                  type: array
                  items:
                    type: string
                  example: ["\nUser:", "\nAssistant:"]
                tools:
                  type: array
                  items:
                    type: object
                    properties:
                      type:
                        type: string
                        example: function
                      function:
                        type: object
                        properties:
                          name:
                            type: string
                            example: getWeather
                          description:
                            type: string
                            example: Gets the current weather for a given city.
                          parameters:
                            type: object
                            properties:
                              type:
                                type: string
                                example: object
                              properties:
                                type: object
                                properties:
                                  city:
                                    type: object
                                    properties:
                                      type:
                                        type: string
                                        example: string
                                      description:
                                        type: string
                                        example: The name of the city
                              required:
                                type: array
                                items:
                                  type: string
                                  example: city
                contents:
                  type: array
                  items:
                    type: object
                    properties:
                      role:
                        type: string
                        example: user
                      parts:
                        type: array
                        items:
                          type: object
                          properties:
                            text:
                              type: string
                              example: "What's the weather like in Tokyo?"
                safety_settings:
                  type: array
                  items:
                    type: object
                    properties:
                      category:
                        type: string
                        example: harm
                      threshold:
                        type: string
                        example: block_low
                generation_config:
                  type: object
                  properties:
                    temperature:
                      type: number
                      format: float
                      example: 0.8
                    top_p:
                      type: number
                      format: float
                      example: 0.9
                    top_k:
                      type: integer
                      example: 40
                    candidate_count:
                      type: integer
                      example: 1
                    max_output_tokens:
                      type: integer
                      example: 512
                    stop_sequences:
                      type: array
                      items:
                        type: string
                        example: ["\n"]
                frequency_penalty:
                  type: number
                  format: float
                  example: 0.1
                presence_penalty:
                  type: number
                  format: float
                  example: 0.3
                n:
                  type: integer
                  example: 1
                response_format:
                  type: object
                  properties:
                    type:
                      type: string
                      example: json
                seed:
                  type: integer
                  example: 42
                tool_choice:
                  type: string
                  example: auto
                user:
                  type: string
                  example: user-1234
                logprobs:
                  type: boolean
                  example: false
                top_logprobs:
                  type: integer
                  example: 5
                system:
                  type: string
                  example: You are a helpful assistant.
                top_k:
                  type: integer
                  example: 50
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
                properties:
                  provider:
                    type: string
                    example: openai
                  model:
                    type: string
                    example: GPT-4.1
                  role:
                    type: string
                    example: assistant
                  content:
                    type: string
                    example: The weather in Tokyo is currently sunny with a high of 28°C and a low of 21°C.
                  usage:
                    type: object
                    properties:
                      input_tokens:
                        type: integer
                        example: 42
                      output_tokens:
                        type: integer
                        example: 57
                      total_tokens:
                        type: integer
                        example: 99
                  finish_reason:
                    type: string
                    example: stop
      security:
        - BearerAuth: []
components:
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer