UMA Addresses
The UMA address format is based on Lightning Addresses (LUD-16), and
are themselves valid LNURL Lightning Addresses when the $ is stripped. They are in the format $<username>@<domainname>
(eg. $alice@somevasp.com). Similar to Lightning Addresses (LUD-16),
the domain will be used to make the first lnurlp call to somevasp.com.
- Must start with a $ symbol. This is to differentiate from email addresses and clearly identify an uma address.
- The <username> portion is limited to
a-z0-9-_.+
- Addresses are case-insensitive, but by convention are written only with lowercase letters
- Like email addresses, the maximum number of characters for the <username> portion of the address is 64 characters (including the $).
The UMA SDK validates these requirements and will throw an error if they are not met.
UMA addresses are valid Lightning Addresses when the leading $ is stripped. Receiving VASPs who choose to support
plain LNURL-PAY transactions (which is a subset of UMA) should treat an incoming LNURLP request to a receiver
without a leading $ as a request to pay the receiver directly via LNURL-PAY. This way, users can still have a
single user name compatible with both UMA and LNURL, while keeping a clear distinction between the two for cases
where a VASP has to understand regulatory requirements.