YouTube Transcript API

Please help me write a data collection script with the EveryInfra YouTube Transcript endpoint (youtube/transcript).

Endpoint contract:
- Request: POST https://api.everyinfra.com/api/v1/social with the header Authorization: Bearer <API key>. Read the key from the EVERYINFRA_API_KEY environment variable and never hard-code it.
- In the request body, set platform to youtube and action to transcript, and put the parameters inside params.
- Required parameters:
  - url: The target URL required by YouTube actions. Use full channel URLs for profile and user_posts, or specific watch?v= and share links for video, comments, and transcript.
- Optional parameters:
  - language: The requested language code for transcript content. Subtitles are returned based on available tracks; automatic translation is not guaranteed.
- Returns one object. Main fields: id, url, title, text, segments, language, available_languages, channel_id, channel_name, channel_username, view_count, like_count; 14 fields in total, full list at https://api.everyinfra.com/api/v1/social/catalog?platform=youtube.
- Example request body:
{
  "platform": "youtube",
  "action": "transcript",
  "params": {
    "url": "https://www.youtube.com/watch?v=dQw4w9WgXcQ"
  }
}
- Price: $0.56 per 1,000 requests; failed and empty results are not charged.
- For dozens or hundreds of targets, add "mode": "async" to the body: you get a job_id at once and poll GET https://api.everyinfra.com/api/v1/jobs/{job_id} for the result.
- On 422, fix the request using the suggested parameter names and allowed values in the error; on 429 or 503, wait for Retry-After and try again.

Before writing code, ask me which targets I need, how many, which fields, and what output format I want; then confirm the plan and the rough cost with me.