wright

wright /rīt/ — noun: a maker or builder. From Old English wyrhta (worker), as in shipwright, wheelwright, playwright. Here: a wright for your recipes, assemblies, and bills of materials.

Pure Python library for production planning, cost calculation, shopping list generation, allergen detection, nutrition analysis, and supply tracking.

Data-source agnostic. No I/O inside the core — models are plain Pydantic, the PurchasedItem protocol accepts anything. Subclass to add your own fields.

Domains: food recipes, construction materials, brewing grain bills, manufacturing BOMs — any domain where you need to aggregate named items with quantities and units into a consolidated supply list with costs.

pip install wright-core

Recipes and ingredients

from wright import Recipe, Ingredient, RecipeComponent

cake = Recipe(
    name="Lemon Cake",
    components=[
        RecipeComponent(
            name="Batter",
            ingredients=[
                Ingredient(name="Flour", quantity=300, unit="g"),
                Ingredient(name="Butter", quantity=200, unit="g"),
                Ingredient(name="Lemon Juice", quantity=3, unit="tbsp"),
            ],
        )
    ],
    prep_time=30,
    cook_time=45,
    servings=12,
)

# Scale it
double_batch = cake * 2  # same as cake.size_up(2)
half_batch = cake * 0.5

Costing

from decimal import Decimal
from wright import Purchase, calculate_recipe_cost

groceries = [
    Purchase(name="Flour", quantity=1000, unit="g", price=Decimal("3.99")),
    Purchase(name="Butter", quantity=500, unit="g", price=Decimal("5.49")),
    Purchase(name="Lemon Juice", quantity=250, unit="ml", price=Decimal("1.99")),
]

cost = calculate_recipe_cost(cake, groceries)
print(cost.total_cost_range.midpoint)  # → 3.10
print(cost.cost_per_serving_range.midpoint)  # → 0.26

Planning a production run

from datetime import date
from wright import (
    ProductionRun,
    ProductionItem,
    generate_shopping_list,
    group_shopping_items,
    calculate_shopping_list_cost,
    analyze_menu,
    DEFAULT_CATEGORY_RULES,
)

session = ProductionRun(
    date=date(2026, 6, 20),
    production=[ProductionItem(assembly="Lemon Cake", quantity=3)],
    target_dates=[date(2026, 6, 20)],
)

shopping = generate_shopping_list(session, [cake])

Group items by store aisle:

grouped = group_shopping_items(
    shopping.all_items,
    category_rules=DEFAULT_CATEGORY_RULES,
)
for group in grouped:
    for item in group.items:
        print(f"  {item.name:<22s} {item.quantity:g} {item.unit}")

  Dairy & Eggs  ----------------------------------------------
  Butter                        600 g
  Lemon Juice                   9 tbsp

  Dry Goods  -------------------------------------------------
  Flour                         900 g

Enrich with costs and analyze:

costs = calculate_shopping_list_cost(shopping, groceries)
total = sum(c.total_cost for c in costs if c.total_cost is not None)
# → Decimal('9.30')

menu = analyze_menu(
    [ProductionItem(assembly="Lemon Cake", quantity=3)],
    [cake],
    groceries,
)
for item in menu.top_drivers:
    print(f"  {item.name}: ${item.total_cost} ({menu.cost_share(item):.0%})")
# → Butter: $3.29 (35%)
# → Flour: $2.39 (26%)

Full grocery list example with 3 recipes, 16 grocery items, and formatted output. Meal prep planner — 5-day week, 2 cook sessions, macros per day.

Allergens and dietary badges

from wright import detect_allergens, detect_dietary_properties

allergens = detect_allergens(cake, allergy_map={"milk": "Dairy", "wheat": "Wheat"})
# → ["Dairy", "Gluten", "Eggs"]

badges = detect_dietary_properties(cake)
# → ["VEGAN", "DAIRY-FREE", "GLUTEN-FREE"]

Supplement keyword detection with purchase data:

badges = detect_dietary_properties(
    cake,
    ingredient_properties=lambda ing: (
        frozenset({"vegan", "gluten-free"}) if "gf" in ing.require_tags else frozenset()
    ),
)

Nutrition

from wright import calculate_recipe_macros, NutritionInfo, FoodRecord

registry = [
    FoodRecord(
        ingredient="Flour",
        nutrition=NutritionInfo(protein_g=10, carbs_g=76, fat_g=1, kcal=364),
    ),
    FoodRecord(
        ingredient="Butter",
        nutrition=NutritionInfo(protein_g=0.9, carbs_g=0.1, fat_g=81, kcal=717),
    ),
]

macros = calculate_recipe_macros(cake, nutrition_registry=registry)
print(macros.per_serving.kcal)

Supply tracking

from wright import Stock, SupplyItem

stock = Stock([SupplyItem(name="Flour", quantity=2000, unit="g")])
stock, deficit = stock.use([SupplyItem(name="Flour", quantity=900, unit="g")])
# deficit → []  — stock covers it

Pricing

from wright import margin_price, multiplier_price

margin_price(Decimal("2.00"), 0.67)  # → 6.06  (67% margin)
multiplier_price(Decimal("2.00"), 3)  # → 6.00  (3× cost)

Everything is injectable

from wright import chain, pinned_picker, cheapest_picker

# Compose pickers: pinned first, then cheapest
picker = chain(pinned_picker({"Butter": my_brand}), cheapest_picker)
items = calculate_shopping_list_cost(shopping, groceries, picker=picker)

# Custom volume display for metric users
shopping = generate_shopping_list(
    session,
    [cake],
    display_normalizer=lambda q, u: ...,
)

# Custom name matcher
cost = calculate_recipe_cost(
    cake,
    groceries,
    matcher=my_fuzzy_matcher,
)

Non-food domains

Assembly, Component, and Material work for construction, brewing, manufacturing, or any bill-of-materials domain. No dummy food fields needed:

from datetime import date
from decimal import Decimal
from wright import (
    Assembly,
    Component,
    ProductionItem,
    ProductionRun,
    Purchase,
    generate_shopping_list,
    calculate_item_costs,
)

# ── Two home projects ──────────────────────────────────────────────────────

deck = Assembly(
    name="Backyard Deck",
    components=[
        Component(
            name="Framing",
            materials=[
                Material(name="2x6 Pressure-Treated", quantity=48, unit="ft"),
                Material(name="Joist Hangers", quantity=16, unit="each"),
            ],
        ),
        Component(
            name="Surface",
            materials=[
                Material(name='5/4" Cedar Decking', quantity=160, unit="ft"),
                Material(name='2" Stainless Screws', quantity=600, unit="each"),
            ],
        ),
    ],
)

bed = Assembly(
    name="Raised Garden Bed",
    components=[
        Component(
            name="Frame",
            materials=[
                Material(name="2x8 Cedar", quantity=24, unit="ft"),
                Material(name='3" Deck Screws', quantity=64, unit="each"),
            ],
        ),
    ],
)

# ── Hardware store prices ──────────────────────────────────────────────────

prices = [
    Purchase(
        name="2x6 Pressure-Treated",
        quantity=8,
        unit="ft",
        price=Decimal("12.97"),
        store="Home Depot",
    ),
    Purchase(
        name='2" Stainless Screws',
        quantity=100,
        unit="each",
        price=Decimal("3.49"),
        store="Home Depot",
    ),
]

# ── Cost one project ───────────────────────────────────────────────────────

deck_costs = calculate_item_costs(deck.all_materials, prices)
total = sum(c.total_cost for c in deck_costs if c.total_cost is not None)
print(f"Deck materials: ${total}")

# Cost breakdown by component (framing vs. surface)
from wright import cost_by_component

breakdown = cost_by_component(deck, prices)
for comp, cost in breakdown.items():
    print(f"  {comp}: ${cost:.2f}")

# Per-linear-foot cost
per_foot = calculate_item_costs(
    deck.all_materials,
    prices,
    per_unit=(1, "ft"),
)

# ── Plan a weekend build session ───────────────────────────────────────────

plan = ProductionRun(
    date=date(2026, 6, 20),
    production=[
        ProductionItem(assembly="Backyard Deck", quantity=1),
        ProductionItem(assembly="Raised Garden Bed", quantity=1),
    ],
    target_dates=[date(2026, 6, 20)],
)

shopping = generate_shopping_list(plan, [deck, bed])
for item in shopping.all_items:
    print(f"{item.name}: {item.quantity:.0f} {item.unit}")

# ── Cross-reference with home inventory ───────────────────────────────────

from wright import Stock, SupplyItem

# What's already in the garage
garage_stock = Stock([
    SupplyItem(name='2" Stainless Screws', quantity=100, unit="each"),
    SupplyItem(name="Joist Hangers", quantity=8, unit="each"),
])

# Deduct stock — get only what you still need to buy
garage_stock, buy_list = garage_stock.use(deck.all_materials)
for item in buy_list:
    print(f"Buy: {item.name} — {item.quantity:.0f} {item.unit}")
# → Buy: 2x6 Pressure-Treated — 48 ft
# → Buy: Joist Hangers — 8 each          (16 needed − 8 on hand)
# → Buy: 5/4" Cedar Decking — 160 ft
# → Buy: 2" Stainless Screws — 500 each  (600 needed − 100 on hand)

The same calculate_ingredient_cost() and Stock work across all domains.

Requirements

Python 3.11+. Dependencies: pydantic>=2.8.2, pint>=0.25, pyyaml>=6.0.3.

License

MIT. See LICENSE.

wright is created and maintained by 3pm German Baking, LLC a farmers market bakery in Asheville, NC.