oneof

Select the first source or destination that can satisfy the transaction. Unlike ordered sources (which split funds across accounts), oneof picks exactly one branch.

Source#

Try each account in order. The first one with sufficient balance handles the entire amount:

send [USD/2 10000] (
  source = oneof {
    @users:1234:main
    @users:1234:savings
    @world
  }
  destination = @merchants:5678
)

If @users:1234:main has 10000 or more, it's used entirely. If not, @users:1234:savings is tried. Falls through to @world only if neither user account can cover the full amount.

This differs from ordered sources ({ @a @b @c }) which would drain @a first, then take the remainder from @b, then @c. With oneof, it's all-or-nothing per branch.

Destination#

send [USD/2 10000] (
  source = @revenue
  destination = oneof {
    max [USD/2 5000] to @payouts:priority
    remaining to @payouts:standard
  }
)

The first matching constraint is used. max caps the amount for that branch; remaining catches everything else.