There is a member with the account name "@lph@" (at-lph-at).

https://api.chess.com/pub/player/@lph@

The player does exist:

https://www.chess.com/member/@lph@

While the name is sub-optimal for V3 with the leading "@", api.chess.com should handle it, or if it can't and it's a very big deal to do so, perhaps the member could be persuaded to change the username. The player is using a free account; a few months of a premium account might be a sweetener if a username change is desirable.

Note: there is also a "lph" aka @lph account.

@@lph@ - ugh.

This doesn't work for me, and I (naturally enough) want to use names as supplied from various lists (national, club members, ...) "as is" without modification.

https://api.chess.com/pub/player/@@lph@

No, there's nobody named @@lph@.  I just tried to put @ in front of the user name to see what happened.

I wondered if the backend code was "helpfully" stripping a leading "@" but it doesn't appear to be. Thus the workaround is to use the website ... which kinda fails for any tools which want the player's stats or profile.

I'm not sure why the request is being rejected, frankly ... but it's a low priority bug to fix. The unavailability (again) of some monthly archives is much higher priority for me. What the developers' priorities are might be a different thing.

@skelos thank you for heads up on this. Actually that kind of username is against our validation rules. We are investigating how it could slip through the validation gates. 

Thanks Andrea. It's a bit of an odd one, but the account is current and in use. Let's hope the user isn't too attached to the name, if it has to change!

Looks like a new admin using the v2 interface a couple years back updated that username. We had him change his username; there are no others with an "@".

Currently, the usernames must be at least 3 and no more than 20 characters, and match the regex /^[a-zA-Z0-9]+([_-][a-zA-Z0-9]+)*$/

However, there are 32,000 existing usernames that were created before that validation was put in place, so there are exceptions. Due to this topic here, I also searched for any other usernames with unusual or invalid characters (lots of spaces and periods), and found 20. We are in the process of getting these changed to something standard.

Thanks, @bcurtis.

ASCII dependency there, English locale dependency there, don't mind me I've been battling internationalisation and localisation on and off since 1990. Unicode helps a lot, but you need a locale for collation. (One of the things Rob Pike and crew at Google missed with Go, although they might have done something by now, but at the time I was wrangling with him (not employed by Google!) he was muttering about libraries and I went back to C.)

And again, ASCII stupid question, get a stupid ANSI.

Oh, I like that.

As a former colleague said, he'd believe our employer took internationalisation seriously when he could log in using the proper spelling of his surname, Bünermann and not have to use Buenermann.

Zoë is different to Zoe too, but let's not get into the different but "equivalent" ways Unicode can represent the former. Anyone would think standards committees wanted sorting to be slow.

I'm waking this thread up because I've found a username which doesn't match the regular expression in post #9, but does work. A leading underscore is apparently acceptable. (I don't see any harm in it either.)

@_Sagittarius_

I don't think the username format need be documented for the API, but this thread is as close to documentation as we have for the format of usernames so maybe someone will find this post useful, sometime.

Good find Giles!

> "there are 32,000 existing usernames that were created before that validation was put in place, so there are exceptions."

There are 32,000 usernames that do not match the regex, but which do have only valid characters. These are mostly leading, trailing, or repeating underscores and hyphens. For example, this chap is heading up 4-Player Chess development: https://www.chess.com/member/_-__-__-___-

Thanks, @bcurtis.

I'd read your comment about cleaning up account names with spaces and periods too broadly. I had, however, read it.  Not carefully enough as you did mention "20" and nobody wants to change 32,000 names.

My apologies for not reading more slowly and thinking more carefully.