IllyVoIPdevelopers

Speech APIs

Transcribe audio

Converts uploaded audio into text.

Try in API Playground ↗Sign in to prepare and run this request.
POST/api/v1/stt/transcribe

Before you start

Upload a supported MP3 or WAV file and an optional language hint.

Result

Read the transcript and returned charge information.

Charges and safe retries

This is a paid transcription request. Do not blindly retry after an uncertain response.

Authentication

Send your account API key in the X-Api-Key header. Keep it on your server; never embed it in browser code.

Request examples

Replace the example values with your own inputs. Examples do not run on this page. Production requests can change your account or incur charges.

cURL

cURL
curl -X POST "https://api.illyvoip.com/api/v1/stt/transcribe" \
  -H "X-Api-Key: ${ILLYVOIP_API_KEY:?Set ILLYVOIP_API_KEY}" \
  -F "file=@sample.mp3" \
  -F "context=speech_api" \
  -F "language=en-US"

Node.js

Node.js
import { openAsBlob } from 'node:fs';
const response = await fetch("https://api.illyvoip.com/api/v1/stt/transcribe", {
  method: "POST",
  headers: {
    "X-Api-Key": process.env.ILLYVOIP_API_KEY
  },
  body: await (async () => {
    const form = new FormData();
    form.append("file", await openAsBlob("sample.wav"));
    form.append("context", "speech_api");
    form.append("language", "en-US");
    return form;
  })()
});

const data = await response.json();
console.log(response.status, data);

PHP

PHP
<?php
$ch = curl_init('https://api.illyvoip.com/api/v1/stt/transcribe');
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'X-Api-Key: ' . getenv('ILLYVOIP_API_KEY')
    ],
    CURLOPT_POSTFIELDS => [
        'file' => new CURLFile('sample.mp3'),
        'context' => 'speech_api',
        'language' => 'en-US'
    ],
]);

$response = curl_exec($ch);
$status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

echo $status . PHP_EOL;
echo $response;

Python

Python
import os
import json
import requests

response = requests.request(
    "POST",
    "https://api.illyvoip.com/api/v1/stt/transcribe",
    headers={
        "X-Api-Key": os.environ["ILLYVOIP_API_KEY"]
    },
    files={
        "file": open("sample.mp3", 'rb')
    },
    data={"context": "speech_api", "language": "en-US"},
)

print(response.status_code)
print(response.json())

Node.js examples run on the server (Node.js 22.17+). Python examples require requests; PHP examples require cURL. Set the environment variables referenced in each example.

Request body

multipart/form-data

Body required.

contextstringoptional

Optional catalog context. Use speech_api for the public STT API or voice_api when you want Voice API recognition defaults.

languagestringoptional

Optional STT language hint. Use the canonical code returned by List STT languages, for example en-US.

filestringrequired
format "binary"

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "context": {
      "type": "string",
      "description": "Optional catalog context. Use `speech_api` for the public STT API or `voice_api` when you want Voice API recognition defaults."
    },
    "language": {
      "type": "string",
      "description": "Optional STT language hint. Use the canonical code returned by `List STT languages`, for example `en-US`."
    },
    "file": {
      "type": "string",
      "format": "binary"
    }
  },
  "required": [
    "file"
  ]
}

Request behavior

Send one multipart file upload. The platform uses the configured speech service.

Conditions and examples

Transcription is billed per started audio minute. Retry and duplicate-charge protection is automatic. Current STT language options: en-US. Call List STT languages first when you want to send an explicit language hint, or omit language to use the default.

Response fields

  • status: Request outcome. Read the resource state separately; success does not always mean delivery or completion.
  • context: Catalog context, such as standalone speech or Voice API.
  • text: Recognized or synthesized text, as described by the endpoint.
  • language: Canonical language code for this request or result.
  • duration_ms: Audio or operation duration in milliseconds.

HTTP responses

Expand a status to inspect its documented response format and examples. Example prices, IDs and timestamps are illustrative values, not quotes or account records.

200 Successful customer-facing response.

application/json

JSON
{
  "status": "success",
  "context": "speech_api",
  "text": "Hello, this is a transcription sample.",
  "language": "en-US",
  "duration_ms": 1840
}
statusstringrequired
enum ["success"]
contextstringrequired
textstringrequired
languagestringrequired
duration_msintegerrequired

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "success"
      ]
    },
    "context": {
      "type": "string"
    },
    "text": {
      "type": "string"
    },
    "language": {
      "type": "string"
    },
    "duration_ms": {
      "type": "integer"
    }
  },
  "required": [
    "status",
    "context",
    "text",
    "language",
    "duration_ms"
  ]
}
400 The request failed validation.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}
401 The API key or browser token is missing or invalid.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}
402 The account has insufficient available credit.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}
403 The account is not allowed to perform this operation.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}
409 The request conflicts with the current resource or operation state.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}
413 The request payload is too large.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}
429 The request rate limit was exceeded.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}
500 An unexpected service error occurred.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}
503 The service is temporarily unavailable.

application/json

statusstringrequired
enum ["error"]
messagestringrequired
error_codestringoptional

Public incident or validation code when the endpoint provides one.

nullable true
fieldsobjectoptional

Public validation details when supplied by the endpoint.

Additional properties: not allowed.

Full schema
Schema
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "status",
    "message"
  ],
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "error"
      ]
    },
    "message": {
      "type": "string"
    },
    "error_code": {
      "type": "string",
      "nullable": true,
      "description": "Public incident or validation code when the endpoint provides one."
    },
    "fields": {
      "type": "object",
      "additionalProperties": true,
      "description": "Public validation details when supplied by the endpoint."
    }
  }
}

Sandbox scenarios

Use https://sandbox-api.illyvoip.com with Sandbox credentials and the X-Illyvoip-Sandbox-Scenario header. Omit the header for the documented success default. This header belongs to sandbox requests.

success, not-found, rate-limited, forbidden, service-unavailable, insufficient-credit, unavailable

Try this operation in Sandbox · Environment setup and limitations

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