Farcaster

Can I change the fname for an Fid? (Not add ens name)

yes, by sending a signed request from a wallet claiming an fname if it is not already taken, or by sending a signed transfer request from the wallet that owns the existing account. You can also check if the name is taken by checking the transfers of that name (if the transfers are empty then no one owns it I guess)

After claiming the name you have to also send a profile update message with username as the type and the claimed name as the value for it to be set at the protocol level

see related links for docs and my implementation (in rust, but it's just a wallet and an HTTP client):

Dad, geek, conversation liquidity provider. vrypan.net (home), /weatherxm (work), @l--o--l (fun). Also https://paragraph.xyz/@purplesubmarine

yes, by sending a signed request from a wallet claiming an fname if it is not already taken, or by sending a signed transfer request from the wallet that owns the existing account. You can also check if the name is taken by checking the transfers of that name (if the transfers are empty then no one owns it I guess)

After claiming the name you have to also send a profile update message with username as the type and the claimed name as the value for it to be set at the protocol level

see related links for docs and my implementation (in rust, but it's just a wallet and an HTTP client):

https://docs.farcaster.xyz/developers/guides/accounts/change-fname

https://github.com/0x330a-public/jesse/blob/master/src/warpcast.rs

basically to claim a previously unused username you set the from = 0 and to = your fid for the signed data, signed by your wallet that owns [your fid] fid. For the transfer you sign it from the [from fid] wallet to verify it's a transfer. I assume that the hubs will query the fname server when validating an incoming user data / username profile data update before storing and propagating that info to the network