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Transcription Models & Aliases

Requires Authentication

In Koldan, transcription and streaming requests are made using transcription model aliases rather than direct transcription model version identifiers. An alias is a stable reference that can be updated to point to different underlying transcription model versions without changing your application code.

Sentence verification (sentver) models are documented separately in Sentence Verification Models. Sentver aliases are not returned by this transcription model API.

Transcription Model Aliases

A transcription model alias can be one of three types:

  • FAMILY: A high-level reference that always points to the latest recommended version of a transcription model family (e.g., large-v3).
  • PINNED: A reference that points to a specific, stable version of a transcription model.
  • CONCRETE: A direct reference to a specific transcription model version (primarily used for internal tracking).

GET /api/v1/speech-services/models

Requires Authentication - Scopes: speech:model-aliases:read

Returns a list of all transcription model aliases accessible to the current user. These are the identifiers you use in transcription and streaming requests.

ModelAliasListResponse

This endpoint returns an array of ModelAliasResponse objects.

ModelAliasResponse
Field Type Nullable Description
id string No Transcription model alias identifier (e.g., large-v3).
type string enum No Alias type. One of: FAMILY, PINNED, CONCRETE.
displayName string No Human-readable name of the transcription model.
description string Yes Brief description of the transcription model's purpose.
status string enum No Availability status. One of: AVAILABLE, UNAVAILABLE, MAINTENANCE, DEPRECATED.
currentVersion string No Current resolved transcription model version name.
capabilities ModelCapabilities No Technical capabilities and supported features.
deprecated boolean No Whether this alias is deprecated.
deprecationDate string (ISO 8601) Yes Date when the alias was marked as deprecated.
deprecationMessage string Yes Information regarding deprecation or migration instructions.
ModelCapabilities
Field Type Nullable Description
languages string[] No List of supported BCP-47 language codes.
supportsLangAutodetect boolean No Whether the transcription model supports automatic language detection.
supportsStreaming boolean No Whether the transcription model supports real-time streaming transcription.
supportsBatch boolean No Whether the transcription model supports batch (offline) transcription.
supportsPunctuation boolean No Whether the engine provides punctuation and capitalization.
supportsDiarization boolean No Whether the engine provides speaker diarization.
supportsItn boolean No Whether the engine provides inverse text normalization.
ModelAliasResponse
{
  "id": "large-v3",
  "type": "FAMILY",
  "displayName": "Large V3 (Multilingual)",
  "description": "Our most accurate multilingual model for general purpose transcription.",
  "status": "AVAILABLE",
  "currentVersion": "v3.0.2",
  "capabilities": {
    "languages": ["en", "he", "fr", "de", "es"],
    "supportsLangAutodetect": true,
    "supportsStreaming": true,
    "supportsBatch": true,
    "supportsPunctuation": false,
    "supportsDiarization": false,
    "supportsItn": false
  },
  "deprecated": false,
  "deprecationDate": null,
  "deprecationMessage": null
}
Status Description
200 OK List of available transcription model aliases returned.
401 Unauthorized Authentication required or token invalid.
403 Forbidden Insufficient permissions (missing speech:model-aliases:read scope).

GET /api/v1/speech-services/models/{model}

Requires Authentication - Scopes: speech:model-aliases:read

Returns detailed information for a specific transcription model alias.

Path Parameters
Field Type Required Description
model string Yes The name of the transcription model alias.
ModelAliasResponse

Returns the same structure as described in the list endpoint.

Status Description
200 OK Transcription model alias details returned.
401 Unauthorized Authentication required or token invalid.
403 Forbidden Insufficient permissions.
404 Not Found Transcription model alias not found.

GET /api/v1/speech-services/models/{model}/languages

Requires Authentication - Scopes: speech:model-aliases:read

Returns a list of supported languages for the specified transcription model alias.

Path Parameters
Field Type Required Description
model string Yes The name of the transcription model alias.
ModelLanguagesResponse
Field Type Nullable Description
model string No The transcription model alias name.
supportsLangAutodetect boolean No Whether the transcription model supports automatic language detection.
languages string[] No List of supported BCP-47 language codes (e.g., en, he).
ModelLanguagesResponse
{
  "model": "large-v3",
  "supportsLangAutodetect": true,
  "languages": ["en", "he", "fr", "de", "es", "it", "ja", "ko"]
}
Status Description
200 OK Supported languages returned successfully.
401 Unauthorized Authentication required or token invalid.
403 Forbidden Insufficient permissions.
404 Not Found Transcription model alias not found.