> ## Documentation Index > Fetch the complete documentation index at: https://apidocs.erlcrussia.com/llms.txt > Use this file to discover all available pages before exploring further. # Speech to text > Turns speech into text. Compatible with `audio.transcriptions` in the OpenAI SDK. Requires a voice AI key (`sk-voice-…`). ## OpenAPI ````yaml en/openapi/en-openai-api-openapi.yaml POST /v1/audio/transcriptions openapi: 3.1.0 info: title: ER:LC Russia - OpenAI-Compatible API version: 1.0.0 description: >- OpenAI-compatible Chat Completions, model listing and retrieval, and speech methods for ER:LC Russia. See each method for its supported parameters. servers: - url: https://api.erlcrussia.com description: Main server - url: https://api.erlcrussia.xyz description: Backup server security: [] tags: - name: Audio - name: Chat Completions - name: Models paths: /v1/audio/transcriptions: post: tags: - Audio summary: Speech to text description: >- Turns speech into text. Compatible with `audio.transcriptions` in the OpenAI SDK. Requires a voice AI key (`sk-voice-…`). requestBody: required: true content: multipart/form-data: schema: type: object required: - file properties: file: type: string format: binary description: >- An audio file in any common format (mp3, mp4, m4a, mpeg, mpga, ogg, wav, webm, flac), up to 25 MB and 120 seconds. model: type: string example: whisper-1 description: >- Accepted for compatibility; transcription always uses the ER:LC Russia model. language: type: string example: ru description: Speech language (ISO-639-1), `ru` by default. response_format: type: string enum: - json - text default: json description: >- `json` returns an object with the text, `text` returns plain text. audio/*: schema: type: string format: binary description: The whole audio file as the request body, any `audio/*` type. responses: '200': description: >- The recognized text. The credits charged are in the `X-Credits-Charged` header. headers: X-Credits-Charged: schema: type: number description: AI credits charged. x-request-id: $ref: '#/components/headers/RequestId' openai-processing-ms: $ref: '#/components/headers/ProcessingMs' x-ratelimit-limit-requests: $ref: '#/components/headers/RateLimitRequests' x-ratelimit-remaining-requests: $ref: '#/components/headers/RateLimitRemainingRequests' x-ratelimit-reset-requests: $ref: '#/components/headers/RateLimitResetRequests' content: application/json: schema: type: object properties: text: type: string example: Как расшифровывается РД? usage: type: object properties: type: type: string example: duration seconds: type: number example: 2.4 example: text: Как расшифровывается РД? usage: type: duration seconds: 2.4 text/plain: schema: type: string '400': description: Invalid request body. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: invalid: value: error: message: Unsupported or corrupted audio file type: invalid_request_error param: null code: null format: value: error: message: 'Unsupported response_format: use json or text' type: invalid_request_error param: null code: null '401': description: The key is missing or invalid. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: >- Incorrect API key provided. Check the key or create a new one in the dashboard. type: invalid_request_error param: null code: invalid_api_key erlc_code: '5008' '413': description: Audio is longer than 120 seconds. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: duration: value: error: message: Audio exceeds 120 seconds type: invalid_request_error param: null code: null size: value: error: message: File exceeds 25 MB type: invalid_request_error param: null code: null '415': description: Unsupported request format. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: Expected multipart/form-data or an audio file type: invalid_request_error param: null code: null '429': description: >- Rate limit exceeded (`type: requests`) or AI credits ran out (`type: insufficient_quota`). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: rate_limit: value: error: message: Rate limit reached. Please slow down and retry later. type: requests param: null code: rate_limit_exceeded erlc_code: '5016' insufficient_quota: value: error: message: >- You exceeded your current quota, please check your plan and billing details. type: insufficient_quota param: null code: insufficient_quota erlc_code: '5038' '502': description: The transcription service did not respond. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: Bad Gateway type: server_error param: null code: '5049' '503': description: The service is temporarily unavailable. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: Audio transcription unavailable type: server_error param: null code: null security: - BearerAuth: [] - ApiKeyAuth: [] components: headers: RequestId: description: Request ID for support. schema: type: string example: req_8f2c1e9b4a7d4c0e9f1a2b3c4d5e6f70 ProcessingMs: description: Request processing time in milliseconds. schema: type: integer example: 412 RateLimitRequests: description: Request limit in the current window. schema: type: integer example: 120 RateLimitRemainingRequests: description: Requests left in the current window. schema: type: integer example: 119 RateLimitResetRequests: description: Time until the limit resets, for example `1s` or `6m0s`. schema: type: string example: 1s schemas: ErrorResponse: type: object description: >- An OpenAI-format error. `code` is an OpenAI string code (`invalid_api_key`, `model_not_found`, `insufficient_quota`, `rate_limit_exceeded`) or `null`. The numeric ER:LC Russia code is in `erlc_code`, see [error codes](/en/documentation/error-codes). properties: error: type: object properties: message: type: string example: Insufficient AI Credits type: type: string enum: - invalid_request_error - insufficient_quota - requests - server_error example: insufficient_quota param: type: - string - 'null' example: null code: type: - string - 'null' example: insufficient_quota erlc_code: type: string description: ER:LC Russia numeric error code. example: '5038' securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: JWT description: >- Passing the authorization token in the Authorization header: Bearer . ApiKeyAuth: type: apiKey in: header name: erlcrussia-api-ai-key description: The key in the erlcrussia-api-ai-key header. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.