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

# Nova 3 (English)

> Transcribe English audio using SLNG-hosted Deepgram Nova 3.

export const HostingBanner = ({type = "slng", provider, regions = []}) => {
  const isSlng = type === "slng";
  const regionLabel = regions.map(r => r.toUpperCase()).join(", ");
  return <div className={`hosting-banner ${isSlng ? "hosting-banner--slng" : "hosting-banner--thirdparty"}`}>
      <span className="hosting-banner__label">
        {isSlng ? "SLNG Sovereign Hosting" : `3rd Party API Hosted by ${provider}`}
      </span>
      <span className="hosting-banner__text">
        {isSlng ? <>
            On demand in: {regionLabel}.{" "}
            <a href="mailto:support@slng.ai">Request here</a> if you want access
            in any other of our 11 regions.
          </> : <>
            For SLNG Sovereign Hosting in any of our 11 regions{" "}
            <a href="mailto:support@slng.ai">contact us</a>.
          </>}
      </span>
    </div>;
};

<HostingBanner type="slng" regions={["ASIA-SOUTH1","AUSTRALIA-SOUTHEAST1","US"]} />


## OpenAPI

````yaml POST /v1/stt/slng/deepgram/nova:3-en
openapi: 3.0.3
info:
  title: SLNG Gateway API - SLNG STT
  version: 0.1.0
  description: Unified API for speech-to-text and text-to-speech services.
  contact:
    name: SLNG Support
    email: support@slng.ai
servers:
  - url: https://api.slng.ai
    description: Production
  - url: https://stageapi.slng.ai
    description: Staging
security:
  - BearerAuth: []
tags:
  - name: Whisper Large v3 (Compressed)
    description: Compressed Whisper Large v3 for faster processing.
  - name: Deepgram Nova 3
    description: Deepgram Nova 3 with VAD and speaker diarization.
  - name: Whisper Large v3
    description: Whisper Large v3 with 99+ language support.
paths:
  /v1/stt/slng/deepgram/nova:3-en:
    post:
      tags:
        - Deepgram Nova 3
      summary: Nova 3 (English)
      description: Transcribe English audio using SLNG-hosted Deepgram Nova 3.
      operationId: slng/deepgram/nova:3-en
      parameters:
        - $ref: '#/components/parameters/XRegionSlngNovaEn'
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              $ref: '#/components/schemas/SlngDeepgramNova3EnRequest'
            examples:
              binary:
                summary: Binary audio upload
                value:
                  audio: <binary>
                  language: en
          application/json:
            schema:
              $ref: '#/components/schemas/SlngDeepgramNova3EnRequest'
            examples:
              url:
                summary: URL-based transcription
                value:
                  url: https://docs.slng.ai/audio/hello.wav
                  language: en
      responses:
        '200':
          $ref: '#/components/responses/SlngDeepgramSttSuccess'
        '400':
          $ref: '#/components/responses/ProviderBadRequest'
        '401':
          $ref: '#/components/responses/ProviderUnauthorized'
        '413':
          $ref: '#/components/responses/ProviderPayloadTooLarge'
        '500':
          $ref: '#/components/responses/ProviderInternalServerError'
        '503':
          $ref: '#/components/responses/ProviderServiceUnavailable'
components:
  parameters:
    XRegionSlngNovaEn:
      name: X-Region-Override
      in: header
      required: false
      description: Target region override. Auto-selected if not provided.
      schema:
        type: string
        enum:
          - asia-south1
          - australia-southeast1
          - us-east-1
  schemas:
    SlngDeepgramNova3EnRequest:
      allOf:
        - $ref: '#/components/schemas/SttAudioRequestBase'
        - $ref: '#/components/schemas/SlngDeepgramSttOptionsBase'
        - type: object
          properties:
            language:
              $ref: '#/components/schemas/SlngDeepgramNova3EnLanguage'
    SttAudioRequestBase:
      type: object
      properties:
        audio:
          type: string
          format: binary
          description: Audio file (multipart) or base64-encoded audio (JSON).
        url:
          type: string
          description: Publicly accessible audio URL.
          example: https://docs.slng.ai/audio/hello.wav
    SlngDeepgramSttOptionsBase:
      type: object
      description: SLNG-hosted Deepgram STT processing options.
      properties:
        model:
          type: string
          description: Model name override.
          default: nova-3
        enable_partials:
          type: boolean
          description: Enable partial/interim transcription results for streaming.
          default: true
        punctuate:
          type: boolean
          description: Add punctuation and capitalization.
          default: false
        smart_format:
          type: boolean
          description: >-
            Apply formatting to improve readability (dates, times, numbers,
            etc.).
          default: false
        utterances:
          type: boolean
          description: Segment transcript into utterances.
          default: false
        paragraphs:
          type: boolean
          description: Add paragraph formatting.
          default: false
        numerals:
          type: boolean
          description: Convert spoken numbers to digits.
          default: false
        profanity_filter:
          type: boolean
          description: Filter profanity from transcript.
          default: false
        redact:
          type: array
          description: Redact sensitive information (pci, ssn, numbers).
          items:
            type: string
            enum:
              - pci
              - ssn
              - numbers
        detect_language:
          type: boolean
          description: Auto-detect spoken language.
          default: false
        filler_words:
          type: boolean
          description: Include filler words (uh, um) in transcript.
          default: false
        multichannel:
          type: boolean
          description: Enable multi-channel audio processing.
          default: false
        keywords:
          type: array
          description: Keywords to boost recognition accuracy.
          items:
            type: string
        encoding:
          type: string
          description: Input audio encoding.
          default: linear16
          enum:
            - linear16
            - flac
            - mulaw
            - amr-nb
            - amr-wb
            - opus
            - speex
            - mp3
            - mp4
            - webm
            - aac
            - ogg
        sample_rate:
          type: integer
          description: Input audio sample rate in Hz.
          default: 16000
        channels:
          type: integer
          description: Number of audio channels.
          minimum: 1
        endpointing:
          oneOf:
            - type: integer
              minimum: 0
            - type: boolean
          default: 10
          description: >-
            Time in milliseconds of silence before finalizing speech. Enabled by
            default at 10ms on Deepgram's side. Set to false to disable
            endpointing entirely.
        utterance_end_ms:
          type: integer
          minimum: 200
          maximum: 5000
          default: 1000
          description: >-
            Time in milliseconds of silence between words before sending an
            UtteranceEnd message. Default is 1000ms, minimum 200ms, maximum
            5000ms. Requires interim_results (enable_partials) to be true.
        tag:
          type: string
          description: Tag for request tracking.
    SlngDeepgramNova3EnLanguage:
      type: string
      description: Supported English language code.
      example: en
      enum:
        - en
        - en-au
        - en-us
        - en-nz
        - en-gb
        - en-in
    DeepgramSttResponse:
      type: object
      description: 3rd Party Deepgram API response format.
      required:
        - results
      properties:
        results:
          type: object
          properties:
            channels:
              type: array
              items:
                type: object
                properties:
                  alternatives:
                    type: array
                    items:
                      type: object
                      properties:
                        transcript:
                          type: string
                        confidence:
                          type: number
                  detected_language:
                    type: string
        metadata:
          type: object
          properties:
            request_id:
              type: string
            model:
              type: string
    ProviderErrorResponse:
      type: object
      description: >
        Provider error response. Contains error information from the upstream
        provider.

        Common errors include invalid speakers, unsupported languages, or
        malformed requests.
      properties:
        error:
          type: string
          description: >-
            Error type or category (e.g., "TTS service error", "Validation
            error").
          example: TTS service error
        status:
          type: number
          description: >-
            Original HTTP status code from the provider (may differ from gateway
            response code).
          example: 400
        details:
          type: string
          description: >
            Detailed error message from the provider. For TTS errors, this
            typically includes

            the specific validation failure (e.g., invalid speaker ID for the
            selected model/language).
          example: >-
            Rime TTS API error: 400 Bad Request - Invalid argument: Invalid
            speaker: aurelie
      required:
        - error
  responses:
    SlngDeepgramSttSuccess:
      description: Transcription successful.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/DeepgramSttResponse'
          examples:
            basic:
              summary: Basic transcription
              value:
                results:
                  channels:
                    - alternatives:
                        - transcript: hello from sunny barcelona
                          confidence: 0.98
                metadata:
                  request_id: req-123
                  model: nova-3
    ProviderBadRequest:
      description: Bad request - invalid parameters provided.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ProviderErrorResponse'
          examples:
            validation-error:
              summary: Validation error
              value:
                error: Validation error
                details: 'Missing required field: text'
    ProviderUnauthorized:
      description: Invalid or missing API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ProviderErrorResponse'
    ProviderPayloadTooLarge:
      description: Audio file exceeds size limit.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ProviderErrorResponse'
    ProviderInternalServerError:
      description: Internal server error from the provider.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ProviderErrorResponse'
          examples:
            processing-error:
              summary: Processing error
              value:
                error: Service error
                details: Internal processing error
    ProviderServiceUnavailable:
      description: Service unavailable.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ProviderErrorResponse'
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      description: |
        API key issued by SLNG. Pass as `Authorization: Bearer <token>`.

````