Create an option

An option is a separate payoff that can trigger during the projection when its condition is met.

import { currencies, defineModel, entity, field, inflow, option, periods, schedule } from "deccf";

const propertyValue = field({ initial: 1_800_000, next: (previous) => previous * 1.03 });
const property = entity.asset({ fields: { propertyValue } });
const sale = option({
  subject: property,
  direction: inflow,
  currency: currencies.SEK,
  schedule: schedule.annual({ placement: "end" }),
  maxExercises: 1,
  when: (ctx) => ctx.get(propertyValue) >= 2_000_000,
  payoff: (ctx) => ctx.get(propertyValue),
});

const model = defineModel({
  name: "property-sale-option",
  currency: currencies.SEK,
  timeline: periods.annual({ from: "2026-01", count: 12 }),
  entities: { property },
  options: { sale },
});
return model;

Without a schedule, the engine checks the option at the end of every period. The condition must change from false to true for an exercise. The default exercise limit is one; if maxExercises is larger, the condition must become false before it can trigger again. result.option(sale) returns the period values.

The option contributes to the model's net total and valuation metrics as its own result series. It has no automatic category and does not create other cashflows.