How to get Youtube channel details using Youtube data API if channel has custom url

I would like to fetch details of a YouTube channel which has a custom URL, like https://www.youtube.com/c/pratiksinhchudasamaisawesome.

Custom channel URLs follow this format: https://www.youtube.com/c/{custom_channel_name}.

I can fetch the details of YouTube channels by Channel ID and username without any issues. Unfortunately, I need to use the custom channel URL which is the only time I encounter this issue.

I developed my app few months ago, and the custom channel URL was working up until a few days ago. Now, the YouTube data API does not return anything for the YouTube custom channel URL if I try get details using their custom name.

To get the details of this channel: https://www.youtube.com/user/thenewboston, for example, the request would be:

GET https://www.googleapis.com/youtube/v3/channels?part=snippet&forUsername=thenewboston&key={YOUR_API_KEY}

Response

200
- SHOW HEADERS -
{
 "kind": "youtube#channelListResponse",
 "etag": "\"zekp1FB4kTkkM-rWc1qIAAt-BWc/8Dz6-vPu69KX3yZxVCT3-M9YWQA\"",
 "pageInfo": {
  "totalResults": 1,
  "resultsPerPage": 5
 },
 "items": [
  {

   "kind": "youtube#channel",
   "etag": "\"zekp1FB4kTkkM-rWc1qIAAt-BWc/KlQLDlUPRAmACwKt9V8V2yrOfEg\"",
   "id": "UCJbPGzawDH1njbqV-D5HqKw",
   "snippet": {
    "title": "thenewboston",
    "description": "Tons of sweet computer related tutorials and some other awesome videos too!",
    "publishedAt": "2008-02-04T16:09:31.000Z",
    "thumbnails": {
     "default": {
      "url": "https://yt3.ggpht.com/--n5ELY2uT-U/AAAAAAAAAAI/AAAAAAAAAAA/d9JvaIEpstw/s88-c-k-no-rj-c0xffffff/photo.jpg"
     },
     "medium": {
      "url": "https://yt3.ggpht.com/--n5ELY2uT-U/AAAAAAAAAAI/AAAAAAAAAAA/d9JvaIEpstw/s240-c-k-no-rj-c0xffffff/photo.jpg"
     },
     "high": {
      "url": "https://yt3.ggpht.com/--n5ELY2uT-U/AAAAAAAAAAI/AAAAAAAAAAA/d9JvaIEpstw/s240-c-k-no-rj-c0xffffff/photo.jpg"
     }
    },
    "localized": {
     "title": "thenewboston",
     "description": "Tons of sweet computer related tutorials and some other awesome videos too!"
    }
   }
  }
 ]
}

It works perfectly.

Now we have to get details of these channels:

Then we get:

GET https://www.googleapis.com/youtube/v3/channels?part=snippet&forUsername=annacavalli&key={YOUR_API_KEY}

Response

200
- SHOW HEADERS -
{
 "kind": "youtube#channelListResponse",
 "etag": "\"zekp1FB4kTkkM-rWc1qIAAt-BWc/TAiG4jjJ-NTZu7gPKn7WGmuaZb8\"",
 "pageInfo": {
  "totalResults": 0,
  "resultsPerPage": 5
 },
 "items": [
 ]
}

This can be easily reproduced using the API explorer.

Solution

Simplest solution, using API only, is to just use Search:list method of YouTube Data API. From what I can tell (mind you, this is from my own research, official docs say nothing on this subject!), if you search using the custom URL component, with "channel" result type filter and "relevance" (default) sorting, first result should be what you're looking for.

So the following query gets 16 results, with the first one being the one you're looking for. Same goes for all other custom channel URLs I tested, so I think this is the most reliable way of doing this.

GET https://www.googleapis.com/youtube/v3/search?part=id%2Csnippet&q=annacavalli&type=channel&key={YOUR_API_KEY}

The other idea is just scraping YouTube page at the custom URL, where you can find ChannelID in one of the meta tags in HTML code. But that's ineffective, unreliable and AFAIK in violation of YouTube terms of use.

Edit: Well, it returns no results for smaller channels, so it's not reliable at all.