> ## Documentation Index
> Fetch the complete documentation index at: https://docs.costa.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Create chat completion

> Send a chat completion request to a selected model.
The request must contain a "messages" array.




## OpenAPI

````yaml https://raw.githubusercontent.com/costa-security/openapi/refs/heads/main/openapi.yaml post /chat/completions
openapi: 3.1.0
info:
  title: Costa Code API
  version: 0.0.1-rc.1
servers:
  - url: https://{defaultHost}
    variables:
      defaultHost:
        default: ai.costa.app/api/v1
security: []
paths:
  /chat/completions:
    post:
      tags:
        - Chat Completions
      summary: Create chat completion
      description: |
        Send a chat completion request to a selected model.
        The request must contain a "messages" array.
      parameters: []
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                model:
                  type: string
                prompt:
                  type: string
                messages:
                  type: array
                  items:
                    type: object
                    properties:
                      role:
                        type: string
                        enum:
                          - system
                          - user
                          - assistant
                          - tool
                      content:
                        type: string
                    required:
                      - role
                      - content
              required:
                - model
                - messages
                - prompt
      responses:
        '200':
          description: service is up
      security:
        - bearerAuth: []
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: APIKey

````