Read a recipe from a web page. Returns its title, ingredient lines as written, declared servings and instructions, taken from the schema.org data the page publishes for machines. Fails clearly when a page has no structured data rather than guessing at the markup.

Split one ingredient line into quantity, unit, ingredient and preparation note. Reports what is ambiguous instead of resolving it: '1 medium onion' comes back flagged as a size descriptor, never as a weight in grams.

Search USDA FoodData Central for a food. Prefer Foundation and SR Legacy results for whole ingredients: they are laboratory-analysed and carry portion weights. Use Branded only for packaged products. Show the user the candidates and let them choose; do not pick silently.

Per-100 g macros for one USDA food id, with its portion weights. Also reports which energy nutrient was used, since Foundation foods report Atwater factors rather than a plain energy value.

Per-100 g macros for a packaged product from Open Food Facts. Community-contributed label transcriptions, so confidence is medium rather than high.

Convert an amount to grams. Mass units are exact. A volume or a count needs either the food's own USDA portion weights, which you get by passing fdcId, or a sourced density row. When neither is available the answer is unresolved with candidates attached, because a cup of flour and a cup of honey do not weigh the same.

Total the macros of a whole batch from its ingredients. Each ingredient needs a nutrition source and a weight. Any ingredient missing either is returned in unresolved with candidate matches and is never dropped or approximated: the totals then carry isComplete false and are a partial sum.

Convert batch totals into per-100 g cooked values. Pass the measured cooked weight when you have it. Failing that, pass a yield factor you measured yourself, or a yieldHint to look one up in the bundled USDA tables. A hint matching several rows returns unresolved with candidates rather than choosing one. Note that rice and dried legumes gain weight: their yield factors are above 1.

Split a cooked batch into portions that are sized per eater rather than divided equally. Each portion carries its own rule: solve for what an eater still needs today, take a fixed weight, hit a macro target, take the remainder, or set food aside for later. Returns each portion's weight and macros, which constraint decided the weight, and where the other targets landed. Asking for more than the batch holds is an error, never a silent scale-down. Weights are rounded to the gram for reporting, so adding up the portions can differ from the batch by a gram; allocatedG and leftoverG carry the exact figures.

Work out how much to cook, from an explicit list of who is eating and how much each takes. Size slots by weight or by macros where you can. Sizing a slot as a count of the recipe's declared servings always warns, because 'serves 4' is the author's claim about their own portions and not a measurement of a household meal. Returns the arithmetic so it can be checked.

Scale a raw ingredient list. Scaling to a macro target needs the recipe's current totals, from computeBatchMacros: this server does not infer what a recipe contains. Amounts in discrete units such as eggs are reported when they land on a fraction, never rounded here.

Aggregate raw quantities across recipes, grouped by USDA food category, with what you have on hand subtracted. Two ingredients merge only when they resolve to the same food.