Mistral AI FIM API

openapi: 3.1.0
info:
  title: Mistral AI FIM API
  description: >-
    Fill-in-the-Middle code completion API powered by Codestral. Generates
    code between a given prompt prefix and optional suffix, supporting over
    80 programming languages for inline code completion and code generation.
  version: '1.0'
  contact:
    name: Mistral AI Support
    url: https://docs.mistral.ai/
    email: support@mistral.ai
  termsOfService: https://mistral.ai/terms/
externalDocs:
  description: Mistral AI FIM API Documentation
  url: https://docs.mistral.ai/api/endpoint/fim
servers:
  - url: https://api.mistral.ai/v1
    description: Mistral AI Production
  - url: https://codestral.mistral.ai/v1
    description: Codestral Dedicated Endpoint
tags:
  - name: FIM
    description: Fill-in-the-Middle code completion operations
security:
  - bearerAuth: []
paths:
  /fim/completions:
    post:
      operationId: createFimCompletion
      summary: Mistral AI Create a FIM completion
      description: >-
        Generate code to fill in between a given prompt prefix and optional
        suffix. Powered by Codestral for high-quality code completions across
        80+ programming languages.
      tags:
        - FIM
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/FimCompletionRequest'
      responses:
        '200':
          description: FIM completion response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FimCompletionResponse'
            text/event-stream:
              schema:
                $ref: '#/components/schemas/FimCompletionStreamResponse'
        '400':
          description: Bad request
        '401':
          description: Unauthorized
        '429':
          description: Rate limit exceeded
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: Mistral AI API key or Codestral API key
  schemas:
    FimCompletionRequest:
      type: object
      required:
        - model
        - prompt
      properties:
        model:
          type: string
          description: ID of the model to use
          examples:
            - codestral-latest
        prompt:
          type: string
          description: The text before the code to complete (prefix)
        suffix:
          type: string
          description: The text after the code to complete (optional suffix)
        temperature:
          type: number
          minimum: 0
          maximum: 2
          default: 0.7
          description: Sampling temperature
        top_p:
          type: number
          minimum: 0
          maximum: 1
          default: 1
          description: Nucleus sampling parameter
        max_tokens:
          type: integer
          minimum: 1
          description: Maximum number of tokens to generate
        stream:
          type: boolean
          default: false
          description: Whether to stream partial completions
        stop:
          oneOf:
            - type: string
            - type: array
              items:
                type: string
          description: Stop sequences
        random_seed:
          type: integer
          description: Random seed for deterministic generation
        min_tokens:
          type: integer
          minimum: 0
          description: Minimum number of tokens to generate
    FimCompletionResponse:
      type: object
      properties:
        id:
          type: string
        object:
          type: string
          enum:
            - chat.completion
        created:
          type: integer
        model:
          type: string
        choices:
          type: array
          items:
            type: object
            properties:
              index:
                type: integer
              message:
                type: object
                properties:
                  role:
                    type: string
                  content:
                    type: string
              finish_reason:
                type: string
                enum:
                  - stop
                  - length
        usage:
          type: object
          properties:
            prompt_tokens:
              type: integer
            completion_tokens:
              type: integer
            total_tokens:
              type: integer
    FimCompletionStreamResponse:
      type: object
      properties:
        id:
          type: string
        object:
          type: string
          enum:
            - chat.completion.chunk
        created:
          type: integer
        model:
          type: string
        choices:
          type: array
          items:
            type: object
            properties:
              index:
                type: integer
              delta:
                type: object
                properties:
                  role:
                    type: string
                  content:
                    type: string
              finish_reason:
                type:
                  - string
                  - 'null'