Sender-side helpers for constrained message delivery.
Constrained messages form per-(sender, recipient, secret) sequences, each send anchored to the handshake
registry at an incrementing index. Two consequences shape the whole flow: sends on one sequence are strictly
ordered across transactions (parallel sends collide or fail the predecessor check, while distinct recipients are
distinct sequences and parallelize), and batching several sends onto one sequence within a transaction requires
an already-committed handshake.
See [constrain_secret] for how a send is anchored to the registry,
Sender-side helpers for constrained message delivery.
Constrained messages form per-
(sender, recipient, secret)sequences, each send anchored to the handshake registry at an incrementing index. Two consequences shape the whole flow: sends on one sequence are strictly ordered across transactions (parallel sends collide or fail the predecessor check, while distinct recipients are distinct sequences and parallelize), and batching several sends onto one sequence within a transaction requires an already-committed handshake.See [
constrain_secret] for how a send is anchored to the registry,