# Get unique ID on the frontend **URL:** \ **Category:** Language Support\ **Tags:** Motoko\ **Created:** [August 10, 2021, 1:56am UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383 "2021-08-10T01:56:13Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![apotheosis](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/apotheosis/32/24516_2.png) [@apotheosis](https://forum.dfinity.org/u/apotheosis)\ **Post date:** [August 10, 2021, 1:56am UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383/1 "2021-08-10T01:56:13Z")
I am looking for a way to get a unique ID for the user after they sign-in using the normal IC method. There is a local cookie ic-identity which changes every time a user logs in and logs out. Is there any way to get a unique id on the frontend from their identity, that is the same each time a user logs in? ---
**Author:** ![apotheosis](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/apotheosis/32/24516_2.png) [@apotheosis](https://forum.dfinity.org/u/apotheosis)\ **Post date:** [August 10, 2021, 4:01am UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383/2 "2021-08-10T04:01:45Z")
Tried this ``` public shared (msg) func sendId(): async Text { return Principal.toText(msg.caller) }; ``` But then get an error ```auto Reject text: Canister ryjl3-tyaaa-aaaaa-aaaba-cai trapped explicitly: IDL error: byte read out of buffer ``` Any ideas? ---
**Author:** ![apotheosis](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/apotheosis/32/24516_2.png) [@apotheosis](https://forum.dfinity.org/u/apotheosis)\ **Post date:** [August 10, 2021, 4:35am UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383/3 "2021-08-10T04:35:43Z")
After I cleared that error I get ```auto Canister ryjl3-tyaaa-aaaaa-aaaba-cai trapped explicitly: IDL error: unexpected IDL type when parsing Principal ``` ---
**Author:** ![apotheosis](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/apotheosis/32/24516_2.png) [@apotheosis](https://forum.dfinity.org/u/apotheosis)\ **Post date:** [August 10, 2021, 5:04am UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383/4 "2021-08-10T05:04:57Z")
I was able to resolve this by removing the .dfx directory and rebuilding everything. ---
**Author:** ![anon74414410](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@anon74414410](https://forum.dfinity.org/u/anon74414410)\ **Post date:** [August 10, 2021, 4:18pm UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383/5 "2021-08-10T16:18:22Z")
Great question! The identity you get back each time is a DelegationIdentity, which will be different every time, but will resolve to a stable principal. If you are using the auth-client package, you can access the principal with a logged-in auth-client using `authClient.getIdentity().getPrincipal().toText();` ---
**Author:** ![apotheosis](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/apotheosis/32/24516_2.png) [@apotheosis](https://forum.dfinity.org/u/apotheosis)\ **Post date:** [August 11, 2021, 12:38am UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383/6 "2021-08-11T00:38:59Z")
This is exactly what I was looking for!! 🥳 ---
**Author:** ![mymikemiller](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/mymikemiller/32/694_2.png) [@mymikemiller](https://forum.dfinity.org/u/mymikemiller)\ **Post date:** [March 25, 2022, 9:36pm UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383/7 "2022-03-25T21:36:23Z")
@anon74414410 Is this ID ok to treat as public information, or should it be kept secret? For my purposes, I need an ID associated with each user that I can insert into URLs to track which user is making which request, and to share publicly with other users to track which user made the referral, for example. I was hoping to use one that the IC already associated with a user, but I obviously don’t want to use one that’s supposed to be kept private. Another option I though of would be to use the user’s Identity Anchor, but I imagine that one is supposed to be kept a little more private, since if someone knows your anchor, they’re one step closer to being able to impersonate you. But at least the Identity Anchor is a number that a user already knows about and has memorized because they need to use it to authorize other computers/browsers. The benefit of using the Identity Anchor for my purposes is that it’s short. The principal, as text, is awfully long (e.g. pn7z4-vnyzv-z2x4g-joqbh-d435q-ejxg4-zb8vq-2mdz6-ce83g-5whwy-mte). Perhaps there’s a shorter unique id per user? The anonymous user’s principal is pretty short (2vxsx-fae) but it seems like actual users get much longer principals? I can, of course, avoid all these problems by generating a random, short id per user, or allowing the user to choose a username, but I thought it’d be cool to use an id that the IC already knows about. ---
**Author:** ![anon74414410](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@anon74414410](https://forum.dfinity.org/u/anon74414410)\ **Post date:** [March 25, 2022, 10:03pm UTC](https://forum.dfinity.org/t/get-unique-id-on-the-frontend/6383/8 "2022-03-25T22:03:12Z")
Principals are public and free to share. There is no API to access a user’s identity anchor, and it’s not recommended regardless. You are best off associating principals with user ID’s, usernames, or alternately finding some way to authenticate with one of the IC naming registries - [https://icns.id/](https://icns.id/) or [https://icnaming.com/](https://icnaming.com/)