Stable capabilities
Ordered by level: primitives at the bottom of the graph, workflows at the top. Each one carries its own tests, at least 8 per function.
Suites — the capabilities a kind of app is built from: accounting, payroll, an online shop, a clinic…
Collection: React form elements — accessible form components for React, and the pure helpers they use.
Level 0 primitive
collections.chunk
Split a list into consecutive batches of at most n items, in order; the last batch may be short.
chunk in TypeScript
crypto.constant-time-equal
Compare two byte strings in time that does not depend on where they differ, for checking MACs and hashes.
constantTimeEqual in TypeScript
geo.distance
Great-circle distance in metres between two latitude/longitude points (haversine), to the millimetre.
distance in TypeScript
dates.quarter
Calendar quarter and fiscal quarter of a date, with the fiscal year and quarter date ranges, for any start month.
quarter in TypeScript
encoding.base64
Bytes to base64 and base64url text and back (RFC 4648), with strict decoding, identically in every language.
A group of 4:
base64Encode, base64Decode, base64UrlEncode, base64UrlDecode
encoding.hex
Bytes to lowercase hexadecimal text and back (RFC 4648 base16), strictly, identically in every language.
A group of 2:
hexEncode, hexDecode
geo.point-in-polygon
Whether a latitude/longitude point lies inside a polygon (ray casting; the boundary counts as inside).
pointInPolygon in TypeScript
math.exp
e to the power x from + - * / only, so TypeScript, Python and Rust return the same double for the same input.
exp in TypeScript
math.integer-sqrt
Exact integer square root: the largest whole number whose square does not exceed n.
integerSqrt in TypeScript
math.round-div
Integer division with an explicit rounding mode, for money arithmetic that must not drift.
roundDiv in TypeScript
math.round-float
Round a float half away from zero to 0-12 decimal places, identically in TypeScript, Python and Rust.
roundFloat in TypeScript
text.mask
Mask all but the last n characters of a card, account or phone number, optionally keeping separators.
mask in TypeScript
validation.bic
Check the format of a SWIFT/BIC code (8 or 11 characters) and split it into its parts.
validateBic in TypeScript
validation.isbn
Check an ISBN-10 or ISBN-13 and convert between them; the normalised form is always the ISBN-13.
validateIsbn in TypeScript
validation.vin
Check a 17-character vehicle identification number and its check digit; enforced for North American VINs.
validateVin in TypeScript
dates.add-months
Add calendar months to an ISO date, clamping to the month end: 31 Jan + 1 month is 28 or 29 Feb.
addMonths in TypeScript
education.academic-year
The academic year and term a date falls in: 1 September to 31 August by default, terms from the caller.
academicYear in TypeScript
encoding.utf8
Text to UTF-8 bytes and strictly back (RFC 3629), so hashing and signing see the same bytes in every language.
A group of 2:
utf8Encode, utf8Decode
logistics.hs-code-validate
Check the format of a commodity code: 6-digit HS, 8-digit CN or 10-digit TARIC/UK code, with chapter and heading checks.
validateHsCode in TypeScript
math.basis-points
Convert a rate between percent, basis points and a plain ratio exactly, as decimal text or integer basis points.
A group of 3:
convertRate, toBasisPoints, fromBasisPoints
math.big-integer
Exact integer arithmetic of any size, on decimal strings, for powers and products that overflow 64 bits.
calculateBigInteger in TypeScript
math.clamp
Clamp an integer to an inclusive range, refusing a range whose bounds are the wrong way round.
clamp in TypeScript
math.pow
base to the power exponent from + - * / only, exact by squaring for whole exponents, identical in every language.
pow in TypeScript
math.sin-cos
Sine and cosine of an angle in radians from + - * / only, so every language returns the same doubles.
sinCos in TypeScript
money.currency-digits
How many decimal places a currency's minor unit has, from the ISO 4217 list.
currencyDigits in TypeScript
text.format-decimal
Format a float as plain decimal text with fixed or trimmed places and optional grouping, identically in every language.
formatDecimal in TypeScript
text.initials
Initials from a personal name for avatars and signatures: "Jean-Paul Sartre" is "JPS".
initials in TypeScript
validation.lei
Check a 20-character Legal Entity Identifier against its ISO 17442 / ISO 7064 MOD 97-10 check digits.
validateLei in TypeScript
charts.contrast
WCAG 2.x contrast ratio between two colours, and which text colour reads best on a background.
A group of 2:
contrastRatio, readableTextColor
crypto.hmac-sha256
HMAC-SHA256 of a message under a secret key (RFC 2104, RFC 4231), in pure code that also runs in the browser.
hmacSha256 in TypeScript
dates.day-of-week
The ISO 8601 day of the week for a date: 1 is Monday through 7 is Sunday.
dayOfWeek in TypeScript
dates.days-between
Calendar days from one ISO date to another, signed: negative when the second date is earlier.
daysBetween in TypeScript
stats.percentile
Percentile of a list of numbers by a named method: nearest-rank, or linear interpolation (R-7, Excel PERCENTILE.INC).
percentile in TypeScript
subscriptions.trial-end
When a free trial ends and the first payment is due, from the trial's start date and length in days.
trialEnd in TypeScript
text.integer-to-words
Spell out a whole number in British English words, with "and" the way a cheque writes it.
integerToWords in TypeScript
time.iso-to-unix
An RFC 3339 timestamp with a Z or offset, such as 2026-09-26T13:00:00+01:00, to Unix time in whole seconds.
isoToUnix in TypeScript
time.round-to-increment
Round a duration in minutes to a billing increment such as 6 or 15 minutes, up, down or to nearest.
roundToIncrement in TypeScript
validation.uk-company-number
Check a Companies House company number's format and prefix (SC, NI, OC, LP...) and zero-pad it to eight characters.
validateUkCompanyNumber in TypeScript
charts.color
Hex colours to RGB and back, and sRGB channels to linear light and back, identically in every language.
A group of 4:
parseHex, toHex, srgbToLinear, linearToSrgb
charts.extent
The minimum and maximum of a series as [min, max], skipping gaps (null), or null when there is no value.
extent in TypeScriptLevel 1 generic concept
agri.field-area
Field area in square metres, hectares and acres from a boundary polygon of latitude/longitude points.
fieldArea in TypeScript
money.compare
Compare two amounts of one currency, refusing to compare across currencies; min, max and clamp too.
A group of 4:
compareMoney, minMoney, maxMoney, clampMoney
money.parse
Parse "£1,234.50" or "1.234,50 €" into integer minor units, strictly: no guessing, no rounding.
parseMoney in TypeScript
money.split-even
Split an amount into n near-equal parts that add back up to exactly the whole.
splitEven in TypeScript
net.ipv4
Parse, format and check dotted-quad IPv4 addresses, refusing leading zeros, octal, hex and short forms.
A group of 3:
parseIpv4, formatIpv4, isIpv4
professional.utilisation
Billable utilisation and billing, collection and overall realisation rates, in basis points.
utilisationRates in TypeScript
react.form.form-field React ^19 · TypeScript only
Wire a label, hint and error message to one form control by id, the accessible way (GOV.UK form group pattern).
A group of 2:
fieldIds, FormField
stats.moving-average
Simple or exponential moving average over a series, one value per full window, rounded to stated decimals.
movingAverage in TypeScript
charts.downsample
Reduce a long series to a few points that keep its visual shape, by Largest-Triangle-Three-Buckets (LTTB).
downsample in TypeScript
collections.sort-by
Stably sort records by one key, ascending or descending, with a total order across mixed types.
sortBy in TypeScript
dates.age
Age in whole years on a given date, with 29 February birthdays ageing on 1 March in other years.
age in TypeScript
energy.meter-advance
Units consumed between two meter reads, counting the meter rolling over past all nines once.
meterAdvance in TypeScript
fleet.emissions
Vehicle greenhouse gas emissions (grams CO2e) from fuel used or distance, using UK government DESNZ conversion factors.
fleetEmissions in TypeScript
inventory.eoq
Economic order quantity (Harris/Wilson): the order size that minimises ordering plus holding cost, in whole units.
economicOrderQuantity in TypeScript
monitor.rollup
Aggregate a metric series into fixed time buckets (count, min, max, avg, sum, last), empty buckets included.
rollup in TypeScript
monitor.uptime
Time-weighted uptime of a target over a window from its checks, with gaps longer than a limit counted as unknown.
uptime in TypeScript
net.ipv6
Parse IPv6 addresses and write them in RFC 5952 canonical form: lower-case, zeros compressed, IPv4 embedded.
A group of 3:
parseIpv6, formatIpv6, isIpv6
agri.yield-per-hectare
Crop yield per hectare and per acre from harvested quantity and field area in any area unit, exactly, as decimal text.
yieldPerHectare in TypeScript
auth.jwt
Sign, verify and decode HS256 JSON Web Tokens (RFC 7519): signature, algorithm and exp/nbf/iat checked with leeway.
A group of 3:
signJwt, verifyJwt, decodeJwt
charity.regular-giving-schedule
Collection dates for a regular gift: monthly, quarterly or annual on a day, clamped to short months, after a lead time.
regularGivingSchedule in TypeScript
charts.interpolate-color
The colour at a point along a sequential or diverging ramp, mixed in OKLab so steps look even; hex in, hex out.
interpolateColor in TypeScript
charts.palette
A categorical palette of n colour-blind-safe colours for chart series: Okabe-Ito or Paul Tol's bright scheme.
palette in TypeScript
charts.ticks
Axis ticks: a round step (1, 2 or 5 x 10^k), the ticks on it, and calendar ticks from days to years.
A group of 4:
tickStep, niceTicks, timeTickInterval, timeTicks
collections.diff
Compare two lists of records by key: which were added, which removed, and which changed and in what fields.
diffByKey in TypeScript
energy.degree-days
Heating and cooling degree days from daily mean temperatures and a base temperature, exact to 0.1.
degreeDays in TypeScript
finance.ledger.journal-validate
Check a double-entry journal: debits equal credits, no zero or two-sided lines, one currency, well-formed account codes.
validateJournal in TypeScript
fleet.cost-per-mile
Whole-life cost per mile of a vehicle, in tenths of a penny, from depreciation, fuel, maintenance, insurance and tax.
costPerMile in TypeScript
fleet.ev-charging-cost
Cost of an electric vehicle charge from the energy added, charger efficiency and power, and time-of-use tariff windows.
evChargingCost in TypeScript
hr.absence-bradford-factor
Bradford factor for a set of absence spells: spells squared times total days, which weights frequent short absences.
bradfordFactor in TypeScript
math.rational
Exact fraction arithmetic, always reduced, for rates and ratios that must not drift.
A group of 8:
calculateRational, rational, addRational, subtractRational, multiplyRational, divideRational, compareRational, rationalToInteger
monitor.error-budget
How much of an SLO's error budget is allowed, used and left, from good and bad event counts or seconds.
errorBudget in TypeScript
react.form.button React ^19 · TypeScript only
A form button in primary, secondary or warning style that stays focusable while loading (GOV.UK button).
Button in TypeScript
react.form.checkbox-group React ^19 · TypeScript only
A question answered by ticking any of several checkboxes, with item hints and an exclusive "None" (GOV.UK checkboxes).
A group of 2:
toggleValue, CheckboxGroup
retail.coupon-validate
Check a coupon against a basket: dates, usage limits, eligible products and minimum spend, with reason codes.
validateCoupon in TypeScript
retail.gift-card-balance
Apply a payment from a gift card, redeeming part of the balance or all of it, and say what is still due.
redeemGiftCard in TypeScript
retail.volumetric-weight
Chargeable parcel weight: the greater of actual and volumetric (dimensional) weight, rounded up to a billing step.
chargeableWeight in TypeScript
units.convert
Convert length, mass, area, volume, temperature and energy between units, exactly, as decimal text.
convertUnits in TypeScript
validation.email
Is this a plausible email address? A documented, pragmatic subset of RFC 5322, not the full grammar.
isEmail in TypeScript
validation.nhs-number
Check an NHS number's modulus 11 check digit and normalise it to ten digits.
validateNhsNumber in TypeScript
auth.normalise-email
Trim an email address and lower-case its domain for storage and lookup, or null if it is not a plausible address.
normaliseEmail in TypeScript
charity.donation-matching
Employer match on a donation: a ratio in basis points, limited by a per-donor cap and a programme budget.
donationMatch in TypeScript
charity.gift-aid-eligibility
Whether a UK donation qualifies for Gift Aid: declaration, enough tax paid, and the donor benefit limits.
giftAidEligibility in TypeScript
charts.format
Axis and label text for charts: tick numbers, SI prefixes (1.2k, 3.4M), percentages, dates and money.
A group of 5:
formatTick, formatSi, formatPercent, formatDate, formatMoneyTick
charts.histogram-bins
Bin values into histogram bins on round edges, by Sturges' rule, Freedman-Diaconis, or a fixed width.
histogramBins in TypeScript
collections.dedupe-by-key
Remove records that share a key value, keeping the first or the last of each, in input order.
dedupeByKey in TypeScript
construction.concrete-volume
Concrete for slabs, strip footings, pads and round columns: volume to the litre and an order rounded up to 0.1 m³.
concreteVolume in TypeScript
construction.roof-pitch
Roof pitch in degrees, rafter length and roof slope area from span, rise and length.
roofPitch in TypeScript
education.attendance-rate
Pupil attendance and absence rates in basis points, with the DfE persistent and severe absence flags.
attendanceRate in TypeScript
energy.carbon-emissions
kgCO2e from kWh or litres of a fuel, using the UK government GHG conversion factors for the year.
carbonEmissions in TypeScript
fleet.fuel-cost
Fuel cost of a trip from distance, fuel economy (UK or US mpg, or L/100km) and price per litre, exactly.
fuelCost in TypeScript
hospitality.service-charge
A discretionary service charge on a bill's eligible lines, as a basis-point rate with explicit rounding.
serviceCharge in TypeScript
http.retry-after
Seconds to wait from an HTTP Retry-After header (delay-seconds or an HTTP date), or null if missing or malformed.
retryAfterSeconds in TypeScript
inventory.reorder-point
Reorder point: demand over the supplier lead time, rounded up to whole units, plus safety stock.
reorderPoint in TypeScript
inventory.safety-stock
Safety stock in whole units, by service level and demand variability (z-score) or by max-minus-average.
safetyStock in TypeScript
inventory.stock-turnover
Stock turnover ratio, days inventory outstanding and days of cover for a period, computed exactly.
stockTurnover in TypeScript
manufacturing.batch-size
Economic batch quantity: the EOQ for a batch made at a finite production rate, in whole units.
economicBatchQuantity in TypeScript
money.sum
Total a list of monetary amounts, with an explicit currency for the empty case.
sumMoney in TypeScript
monitor.burn-rate
How fast an SLO's error budget is burning: the error rate as a multiple of the rate the SLO allows, in thousandths.
burnRate in TypeScript
net.cidr
CIDR blocks: network, broadcast, first and last host, host count, netmask and prefix, and membership.
A group of 5:
cidrInfo, cidrContains, isCidr, prefixToNetmask, netmaskToPrefix
net.port
Check a TCP/UDP port number and name the IANA service registered on it, with its system/user/dynamic range.
A group of 2:
isPort, portService
react.form.styles React ^19 · TypeScript only
An optional stylesheet for the react.form elements' caps-* classes, themed by --caps-form-* custom properties.
formStyles in TypeScript
react.form.textarea React ^19 · TypeScript only
A labelled multi-line text box with hint, error and an optional live character or word count (GOV.UK).
Textarea in TypeScript
telecoms.data-allowance
Mobile data allowance used and remaining, and the overage charge in whole blocks with an optional spend cap.
dataAllowance in TypeScript
text.slugify
Turn a title into a lowercase ASCII URL slug, transliterating common accented Latin letters.
slugify in TypeScript
validation.uk-sort-code-account
Check a UK sort code and account number with the Vocalink/Pay.UK modulus rules, against a table you supply.
validateUkSortCodeAccount in TypeScript
agri.growing-degree-days
Growing degree days (thermal time) from daily min/max temperatures, a base and an optional upper cap.
growingDegreeDays in TypeScript
agri.seed-rate
Seed rate in kg/ha from target plants per m², thousand-grain weight and expected establishment.
seedRate in TypeScript
agri.stocking-rate
Stocking rate: livestock units and LU per hectare from animal numbers, by a published LU coefficient table.
stockingRate in TypeScript
auth.bearer-token
The token from an HTTP Authorization header of the form "Bearer <token>" (RFC 6750), or null if it has none.
parseBearerToken in TypeScript
banking.faster-payments-limit
Whether a Faster Payment fits the scheme maximum, the bank's per-payment limit and what is left of its daily limit.
fasterPaymentsCheck in TypeScript
banking.savings-aer
AER (annual equivalent rate) from a gross nominal rate and how often interest is paid, to two decimal places.
savingsAer in TypeScript
charity.fundraising-ratio
Cost to raise £1 and charitable spend ratio for a charity, in exact basis points.
fundraisingRatios in TypeScript
charts.scale
Map data values onto screen positions and back: linear, log, time, band and point scales, and nice domains.
A group of 7:
linearScale, invertLinear, niceDomain, logScale, timeScale, bandScale, pointScale
collections.group-by-key
Group records by the value at one key, preserving input order inside each group.
groupByKey in TypeScript
collections.paginate
Slice a list into a 1-based page and report the totals an API response needs.
paginate in TypeScript
collections.search-text
Filter records by a case-insensitive substring match across named fields, in input order.
searchText in TypeScript
construction.brick-count
Bricks and mortar for a wall, openings subtracted, for UK standard 215 x 102.5 x 65 mm bricks with 10 mm joints.
brickCount in TypeScript
construction.materials-area
Packs of tiles, paint, plasterboard or flooring to cover an area, with waste and coats, rounded up to whole packs.
materialsArea in TypeScript
construction.timber-length
Cutting list: which stock lengths to buy and which pieces to cut from each, allowing for saw kerf.
timberCuttingList in TypeScriptLevel 2 domain function
hospitality.bill-split
Split a restaurant bill evenly, by item or by share, exactly to the penny, with the service charge shared in proportion.
billSplit in TypeScript
finance.proration
Split an amount into the part used and the part unused over a billing period, losing nothing.
prorate in TypeScript
validation.uk-postcode
Validate a UK postcode and normalise it to canonical upper case with one space before the inward code.
validateUkPostcode in TypeScript
agri.fertiliser-application
Fertiliser product rate (kg/ha and total) to meet N, P2O5 and K2O targets from its analysis, limiting nutrient first.
fertiliserApplication in TypeScript
auth.access-token
Issue an API's HS256 access token, read one from an Authorization header, and refuse revoked or superseded ones.
A group of 3:
issueAccessToken, readAccessToken, confirmAccessToken
charts.stack
Stack several series for stacked bars and areas: on zero, normalised to 100%, or diverging around zero.
stack in TypeScript
construction.retention
Retention held and released on a construction valuation: full rate, half at practical completion, none at the end.
retention in TypeScript
monitor.mttr
MTTR, MTBF, downtime and incident counts for a reporting window, from a list of incidents.
reliabilityStats in TypeScript
validation.iban
Check an IBAN against the ISO 13616 mod-97-10 checksum and the registered length for its country.
isIban in TypeScript
agri.gross-margin
Enterprise gross margin (output less variable costs), in total and per hectare or per head, in exact money.
grossMargin in TypeScript
dates.uk-tax-year
The UK personal tax year containing a date: 6 April to 5 April, with HMRC's label.
ukTaxYear in TypeScript
education.timetable-clash
Find timetable clashes: overlapping sessions that share a room, a teacher or a student group, in a fixed order.
timetableClashes in TypeScript
energy.price-cap
Ofgem energy price cap unit rate and daily standing charge for a fuel and payment method on a date (GB average).
priceCap in TypeScript
finance.uk-bank-rate
Bank of England Bank Rate (base rate) in force on a date, from the Bank's official history since 2001.
ukBankRate in TypeScript
fleet.mileage-allowance
HMRC approved mileage allowance payments for an employee's own vehicle: tax-free amount, taxable excess or relief.
mileageAllowance in TypeScript
inventory.abc-classification
ABC classes by annual consumption value (Pareto), with configurable cut-offs such as 80/15/5 and deterministic ties.
abcClassification in TypeScript
money.convert
Convert an amount to another currency at a supplied exact rate, with an explicit rounding mode.
convertMoney in TypeScript
telecoms.call-rating
Rate a call from a rate deck: longest-prefix destination match, billing increments, connection fee and minimum charge.
rateCall in TypeScript
todo.parse-date-phrase
Read a typed due date like "tomorrow", "next friday", "in 2 weeks" or "2026-10-01" as a date, relative to today.
parseDatePhrase in TypeScript
banking.fees-cap
Apply a monthly fee cap to a list of account charges: charge up to the cap, waive the rest.
applyFeeCap in TypeScript
charity.gasds
Gift Aid Small Donations Scheme top-up for a tax year: the £8,000 limit, the matching rule and community buildings.
gasds in TypeScript
charity.higher-rate-relief
A Gift Aid donor's extra tax relief at higher, intermediate, additional and top rates, by extending the tax bands.
higherRateRelief in TypeScript
construction.payment-notice-dates
Construction Act default dates: payment due, payment notice, final date for payment and pay-less notice.
paymentNoticeDates in TypeScript
construction.vat-reverse-charge
Whether the UK VAT domestic reverse charge applies to a construction supply, and the invoice wording.
domesticReverseCharge in TypeScript
energy.estimate-read
Estimate a meter read for a date from the average daily consumption between two earlier reads, with rollover.
estimateRead in TypeScript
energy.solar-generation
Estimated annual solar PV generation by the MCS method: kWp x Kk x shade factor, per array and in total.
solarGeneration in TypeScript
energy.tariff-time-of-use
Cost half-hourly consumption against time-of-use rates: Economy 7 windows or Agile-style half-hourly prices.
timeOfUseCost in TypeScript
finance.fx-revaluation
Unrealised foreign exchange gain or loss on foreign-currency balances revalued at a period-end rate.
fxRevaluation in TypeScript
finance.late-payment-interest
UK statutory late payment interest (8% over Bank Rate) and fixed compensation under the Late Payment Act 1998.
latePaymentInterest in TypeScript
hospitality.gross-profit-menu
Menu gross profit (GP%) on the VAT-exclusive price, and the menu price that reaches a target GP.
A group of 2:
menuGrossProfit, menuPriceForGp
hospitality.recipe-cost
Cost a recipe and each portion from ingredient quantities, pack sizes and pack prices, allowing for trim and waste.
recipeCost in TypeScript
logistics.freight-rate
Freight charge from a carrier's dated weight-break tariff for a zone, with the fuel surcharge in force on the ship date.
freightRate in TypeScript
logistics.route-distance
Total great-circle distance of an ordered list of stops, leg by leg, optionally back to the start, to the millimetre.
routeDistance in TypeScript
react.form.password-field React ^19 · TypeScript only
A password input with a Show/Hide button and an optional live checklist of a password policy (GOV.UK password input).
A group of 2:
passwordChecklist, PasswordField
retail.loyalty-points
Loyalty points for a purchase: redeem in blocks, earn on what is paid, with tier multipliers.
loyaltyPoints in TypeScript
retail.promotion-apply
Apply BOGOF, 3-for-2, percent off, amount off and multibuy deals to a basket, best for the customer, allocated to lines.
applyPromotions in TypeScript
retail.shipping-rate
Delivery charge from a dated rate table by service, zone, chargeable weight and size, with a free-over threshold.
shippingRate in TypeScript
todo.due-label
The short English label shown next to a todo: "2 days overdue", "Due today", "Due tomorrow", "Due Fri 2 Oct".
dueLabel in TypeScript
validation.uk-vat-number
Check a UK VAT registration number against HMRC's mod-97 checksum, including the post-2010 9755 variant.
isUkVatNumber in TypeScript
agri.feed-ration
Ration costing and dry matter intake from each feed's fresh weight, DM % and price per tonne, in exact money.
feedRation in TypeScript
banking.cheque-amount-words
The words and figures to write on a cheque: "One hundred and twenty pounds and fifty pence only", "£120.50".
chequeAmountWords in TypeScript
banking.overdraft-interest
Overdraft interest for a statement period from daily balances, with an interest-free buffer.
overdraftInterest in TypeScript
charity.gift-aid
Gift Aid a UK charity can claim on a donation: basic rate tax grossed up, 25p per £1 at 20%.
giftAid in TypeScript
charity.payroll-giving
UK Payroll Giving for one pay period: the donation comes off pay before PAYE, and the tax it saves the employee.
payrollGiving in TypeScript
charts.axis
Axis geometry as data: tick positions, tick marks, label anchors and gridlines for number, time and category axes.
A group of 5:
axisFromTicks, numberAxis, timeAxis, bandAxis, gridLines
charts.shape
SVG path strings for lines, areas, steps, monotone curves, bars, arcs and pie slices, identical in every language.
A group of 7:
linePath, areaPath, stepPath, monotoneCurve, barRects, arcPath, pieAngles
construction.cis-deduction
Construction Industry Scheme deduction (0, 20 or 30%) on the labour part of a subcontractor payment.
cisDeduction in TypeScript
education.student-loan-repayment
A graduate's student or postgraduate loan repayment for a tax year, as Self Assessment works it out.
studentLoanRepayment in TypeScript
finance.compound-interest
Compound interest accrued period by period in minor units, the way a statement is built.
compoundInterest in TypeScript
finance.ledger.trial-balance
Trial balance from journal lines: debit or credit balance per account, and proof that debits equal credits.
trialBalance in TypeScript
inventory.expiry-fefo
First-expiry-first-out pick list for a quantity across batches, skipping expired and short-dated stock.
fefoPick in TypeScript
logistics.demurrage
Demurrage or detention charge for a container: free days, then a tiered daily rate from the carrier's tariff.
demurrage in TypeScript
manufacturing.bom-cost
Rolled-up standard cost of one unit of a product from its BOM, bought-in costs, and labour and overhead rates.
bomCost in TypeScript
manufacturing.bom-explode
Explode a multi-level bill of materials into exact total quantities per component, with scrap and cycle checks.
explodeBom in TypeScript
monitor.burn-rate-alert
Multiwindow, multi-burn-rate SLO alerting: which rules fire, from event counts per window (Google SRE workbook).
burnRateAlert in TypeScript
retail.oss-vat
EU distance-selling VAT: which member state's standard rate applies under OSS and the EUR 10,000 threshold, and the VAT.
ossVat in TypeScript
todo.due-status
Where a todo stands against its due date today: done, overdue, today, tomorrow, this week, later or no date.
dueStatus in TypeScript
todo.export-csv
Write todos as a CSV file (RFC 4180) with one column per field, for backups, spreadsheets and other apps.
exportCsv in TypeScript
todo.item
The to-do item type (Todo, TodoDraft, Recurrence) and its validators, with a message per field.
A group of 2:
validateDraft, validateTodo
todo.recurrence-label
English text for a repeating todo's chip: "Every weekday", "Every 2 weeks on Monday", "Every month on the 31st".
recurrenceLabel in TypeScript
agri.milk-price
Milk price per litre and payment from a contract's base price, butterfat/protein adjustments and bonuses.
milkPrice in TypeScript
auth.login-throttle
Allow a login attempt or lock the account out, from its recent failed attempts, with the seconds until it may retry.
loginThrottle in TypeScript
auth.password-hash
Hash a password for storage as pbkdf2_sha256$iterations$salt$hash, verify one in constant time, and spot weak hashes.
A group of 3:
hashPassword, verifyPassword, passwordNeedsRehash
auth.password-policy
Check a new password against a named policy (NIST SP 800-63B-4 by default): length, common passwords, name and email.
A group of 2:
passwordPolicy, checkPassword
banking.bacs-processing-date
Bacs three-day cycle: input, processing and entry (arrival) dates for a submission, skipping weekends and bank holidays.
bacsProcessingDates in TypeScript
charity.restricted-funds
Allocate charity spending to restricted funds first, then unrestricted funds, never overdrawing a restricted fund.
allocateFundSpend in TypeScript
charts.layout
Chart layout: the plot area inside margins, legend items wrapped into rows, and greedy label collision avoidance.
A group of 3:
plotArea, legendRows, avoidCollisions
construction.day-rate-quote
A trade quote from labour days at a day rate, materials with a markup, and VAT.
dayRateQuote in TypeScriptLevel 3 business operation
finance.credit-note.calculate
Credit note against an original invoice, by units or by amount, with VAT at the original tax point's rates.
calculateCreditNote in TypeScript
finance.invoice.calculate
Calculate a complete invoice: line nets, VAT per line, totals and a VAT summary grouped by rate.
calculateInvoice in TypeScript
charity.reclaim-batch
Gift Aid claim totals for a period from donation records: donor lines, aggregated small gifts, tax due.
giftAidClaimBatch in TypeScript
charts.bar-chart
Complete bar chart geometry as data, grouped or stacked: plot area, axes, gridlines, bar rectangles, colours, legend.
barChart in TypeScript
retail.basket-total
Total a basket: line prices, promotions, a basket discount, VAT per line and delivery, into one checked total.
basketTotal in TypeScript
charts.line-chart
Complete line chart geometry as data: plot area, number or date axes, gridlines, series paths, colours, legend.
lineChart in TypeScript
subscriptions.invoice
A subscription renewal invoice: plan, add-ons and usage, coupon discounts by billing period, and VAT.
renewalInvoice in TypeScript
auth.validate-login
Check a login form (email, password): the normalised email to look up, or a message for each field to fix.
validateLogin in TypeScript
auth.validate-password-change
Check a change-password form: current password given and correct, new one meeting the policy and different.
validatePasswordChange in TypeScript
auth.validate-registration
Validate a sign-up form (email, password, name) in one call, with a message per field, in the browser and the API alike.
validateRegistration in TypeScript
charts.sparkline
A sparkline's SVG path and end marker from a series, fitted into a box, with gaps left as breaks.
sparkline in TypeScript
construction.valuation
Interim valuation: gross value to date, retention, previous payments, amount due, VAT or reverse charge, and CIS.
interimValuation in TypeScript