curl --request POST 'https://api.voicecheap.ai/v1/actions/subtitles_history_duplicate' \
  --header "x-api-key: $VOICECHEAP_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{"historyId":"history_20261016_001","currentSrtContent":"1\n00:00:00,000 --> 00:00:01,500\nHello world.\n","layoutOptions":{"maxLinesPerCaption":2,"maxCharactersPerLine":42},"styleOptions":{"fontFamily":"sans","fontSize":"medium","textColor":"white","backgroundStyle":"outline","position":"bottom"},"requestId":"13579bdf-2468-4ace-8bdf-0123456789ab"}'

const input = {
  historyId: 'history_20261016_001',
  currentSrtContent: '1\n00:00:00,000 --> 00:00:01,500\nHello world.\n',
  layoutOptions: {
    maxLinesPerCaption: 2,
    maxCharactersPerLine: 42,
  },
  styleOptions: {
    fontFamily: 'sans',
    fontSize: 'medium',
    textColor: 'white',
    backgroundStyle: 'outline',
    position: 'bottom',
  },
  requestId: '13579bdf-2468-4ace-8bdf-0123456789ab',
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/subtitles_history_duplicate', {
  method: 'POST',
  headers: {
    'x-api-key': process.env.VOICECHEAP_API_KEY,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify(input),
});
const body = await response.json();
if (!response.ok) throw new Error(body.code + ': ' + body.message);
console.log(body);

import os
import requests

response = requests.post(
    "https://api.voicecheap.ai/v1/actions/subtitles_history_duplicate",
    headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
    json={"historyId": "history_20261016_001", "currentSrtContent": "1\n00:00:00,000 --> 00:00:01,500\nHello world.\n", "layoutOptions": {"maxLinesPerCaption": 2, "maxCharactersPerLine": 42}, "styleOptions": {"fontFamily": "sans", "fontSize": "medium", "textColor": "white", "backgroundStyle": "outline", "position": "bottom"}, "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab"},
    timeout=120,
)
body = response.json()
if not response.ok:
    raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)

{
  "data": {
    "historyId": "history_20261016_copy",
    "revision": 1,
    "updatedAt": 1792152010000,
    "currentSrtContent": "1\n00:00:00,000 --> 00:00:01,500\nHello world.\n"
  },
  "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab"
}

{
  "data": {
    "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab",
    "operation": "subtitles_history_duplicate",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "running",
    "pollAfterSeconds": 5
  },
  "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab"
}

{
  "data": {
    "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab",
    "operation": "subtitles_history_duplicate",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "completed",
    "resultStored": false,
    "message": "The action completed. Retrieve its output from the corresponding history or resource action."
  },
  "requestId": "13579bdf-2468-4ace-8bdf-0123456789ab"
}