Values a currency basket by the fixed-amount method: the currency amounts are fixed at a rebase date and the live weights float daily with FX. The arithmetic this node owns is the derivation, turning target weights and rebase-date rates into the fixed amounts those weights imply, so that amounts are an output of the rebase rather than an input to it.
The demo values below are synthetic and already loaded, so you can press Run without entering anything of your own.
Fixed amounts are the basket's invariant. Weights are not declared, they are derived from what each component contributes today, which is why a basket can drift far from its target weights without anything having been changed. Target weights that do not sum to one are refused rather than silently normalized: a basket derived from them is not a basket.
It does not fetch or verify any FX rate. Every rate, fixed amount and target weight is supplied by you and merely asserted. It does not verify that a stated composition matches any published basket, nor that a preset remains current, since a basket reviewed on a periodic cycle changes on its own schedule. Where per-pair rates cite upstream oracle prints, the citation is recorded but the prints are not checked for freshness or for coming from the same observation window.
ART-560 produces the per-pair prints this node consumes. A basket value is only as auditable as the rates behind it, so citing each print by execution_hash is what turns a stated index level into one a reader can walk back to its inputs.