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

# Speech-to-text

> Transcribe audio with Whisper Large V3, Voxtral, and other ASR models. Multipart form upload.



## OpenAPI

````yaml /api-reference/openapi.json post /audio/transcriptions
openapi: 3.1.0
info:
  title: Runcrate API
  version: 1.0.0
  summary: OpenAI-compatible inference API + GPU infrastructure API.
  description: >-
    Runcrate exposes two API surfaces. The inference API at
    `https://api.runcrate.ai/v1` is OpenAI-compatible — it accepts the standard
    OpenAI SDK with the base URL changed. The infrastructure API at
    `https://runcrate.ai/api/v1` manages GPU instances, persistent volumes,
    environments, SSH keys, templates, and billing. Both share a single
    `rc_live_*` API key.


    Pricing is per-token, per-image, per-second, or per-minute on the inference
    API (varies by model; see https://www.runcrate.ai/api/models/catalog for
    live rates) and per-second on GPU rentals (see
    https://www.runcrate.ai/pricing for hourly rates per GPU class).


    All infrastructure API responses are wrapped in `{ "data": ... }`. List
    responses also include a `meta` object with pagination cursors. Error
    responses use `{ "error": { "code": "...", "message": "..." } }`.
  termsOfService: https://www.runcrate.ai/terms
  contact:
    name: Runcrate
    url: https://www.runcrate.ai/contact
  license:
    name: Proprietary
    url: https://www.runcrate.ai/terms
servers:
  - url: https://api.runcrate.ai/v1
    description: Inference API (OpenAI-compatible)
  - url: https://runcrate.ai/api/v1
    description: >-
      Infrastructure API (instances, storage, environments, ssh-keys, templates,
      billing)
security:
  - ApiKeyAuth: []
tags:
  - name: Chat
    description: OpenAI-compatible chat completions.
  - name: Images
    description: Text-to-image generation.
  - name: Videos
    description: Async text-to-video and image-to-video generation.
  - name: Audio
    description: Text-to-speech and speech-to-text.
  - name: Embeddings
    description: Vector embeddings for RAG and search.
  - name: Models
    description: Model catalog discovery.
  - name: Instances
    description: GPU instance lifecycle.
  - name: Storage
    description: Persistent volume management.
  - name: Environments
    description: Resource isolation containers within a workspace.
  - name: SSH Keys
    description: SSH key management for instance access.
  - name: Templates
    description: Pre-built instance images and configurations.
  - name: Billing
    description: Credit balance, transactions, usage metrics.
paths:
  /audio/transcriptions:
    post:
      tags:
        - Audio
      summary: Speech-to-text
      description: >-
        Transcribe audio with Whisper Large V3, Voxtral, and other ASR models.
        Multipart form upload.
      operationId: createTranscription
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              required:
                - file
                - model
              properties:
                file:
                  type: string
                  format: binary
                  description: Audio file (mp3, wav, m4a, flac, webm, mp4).
                model:
                  type: string
                  example: openai/whisper-large-v3
                language:
                  type: string
                  description: Optional ISO-639-1 hint (e.g. 'en').
                response_format:
                  type: string
                  enum:
                    - json
                    - text
                    - srt
                    - vtt
                  default: json
      responses:
        '200':
          description: Transcription text.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TranscriptionResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/PaymentRequired'
components:
  schemas:
    TranscriptionResponse:
      type: object
      properties:
        text:
          type: string
    Error:
      type: object
      required:
        - error
      properties:
        error:
          type: object
          required:
            - code
            - message
          properties:
            code:
              type: string
              description: >-
                Machine-readable error code (e.g. `validation_error`,
                `unauthorized`, `not_found`, `insufficient_credits`,
                `rate_limited`, `internal_error`).
            message:
              type: string
              description: Human-readable error message.
            details:
              type: object
              additionalProperties: true
              description: Optional structured error context.
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    PaymentRequired:
      description: Insufficient credits.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    ApiKeyAuth:
      type: http
      scheme: bearer
      description: >-
        Use a Runcrate API key with the `rc_live_*` prefix as the bearer token.
        Create one at https://www.runcrate.ai/dashboard/api-keys.

````