TIPAddresses and PDAs
How a tag becomes an address, and why that makes uniqueness free.
Every registered tag lives at a Program Derived Address (PDA): an address computed deterministically from a set of seed bytes and the tip-registry program id, rather than one generated from a keypair. TIP derives this PDA from exactly two seeds, in order:
- the ASCII bytes of the fixed seed prefix
"tag" - the ASCII bytes of the tag's canonical form
Because a PDA is a pure function of its seeds, @daniel can only ever
derive to one address, on any client, in any language, forever. This is
what makes uniqueness a property of the address itself rather than
something a server has to check: there is no way for two different
"daniel" accounts to exist, because there is only one address that
normalizeTag("daniel") plus the seed prefix can ever produce. Registering
a tag that already has an account at its derived address simply fails, the
same way creating a file at a path that is already taken fails.
This also means anyone, not just this project's own client, can compute
where @daniel's account lives and read it directly over RPC, with no API
in between.