Explore APIs

Tip and even bill split in exact cents: tip on subtotal or total, shares that add up, optional round up to whole dollars.

Write a money amount in words for a cheque (EN/ES/FR/DE): you give the currency names, no rates; words or 56/100 cents.

Camelot wheel code for a musical key and its harmonic-mixing matches; optionally test if two keys mix.

Is a date a public holiday in a country? Also whether it is a business day and the next holiday after it.

Check a list of license ids against SPDX: current, deprecated or unknown, with the modern GNU -only / -or-later form.

Parse CSV text (quotes, escaped quotes, embedded commas and newlines) into JSON rows, detecting the delimiter.

Validate a 9-character CUSIP security identifier check digit and split issuer and issue codes.

Estimate a monthly electricity bill from kWh with block-tier rates, a fixed monthly charge and a tax or fee percentage.

Break-even units and revenue from fixed costs, unit price and unit variable cost, plus profit at a target volume.

Compare a file name's extension with its real type from the first bytes; flags executables disguised as documents or images.

CAA records for a domain (walking up to parent names): which CAs may issue certificates, wildcard rules and reporting contacts.

Density altitude from field elevation, altimeter setting and temperature, exact and by rule of thumb, with a performance flag.

How many identical boxes fit inside a larger box or crate: best of six orientations in a simple grid, with utilization.

Compare two packaged foods by barcode: Nutri-Score, NOVA, and per-100 g energy, sugars, saturated fat, salt, fibre and protein.

Add or subtract N business days from a date, skipping weekends and your holiday list, WORKDAY style.

Check whether two words or phrases are anagrams, ignoring case, spaces, punctuation and accents; shows the letter differences.

Convert a number between bases 2 to 36 exactly (binary, octal, decimal, hex), with big-integer precision.

Birthday-problem collision odds for random IDs or hash outputs, or the count of items that reaches a target probability.

Use when an agent is about to pay another agent and needs one finished answer first: should you pay this payee? PayCheck ($0.50) runs Flow's whole checker stack on the payee — payee verdict (kind, activity, contract safety), wallet approval-exposure audit, and recent USDC settlement history on Base — returning one grade (ALLOW / REVIEW / BLOCK, 0-100), a verify_status, all checks, the evidence, an

Home battery storage ROI and payback calculator — Powerwall vs alternatives, backup-power value, with the IRA 30% tax credit and state incentives applied. For homeowner and solar agents.

Goldsky Edge RPC — prepaid balance, funds ~1000 requests at 5 atomic units each

Carbon-to-nitrogen ratio of a compost mix by the Cornell formula, or the greens-to-browns amounts that reach a target ratio.

Competition check for an x402 idea: sellers, hosts, price range and how many have real buyers. Open space or crowded?

Signatures, press sheets and blank pages needed for a book of N pages at 4, 8, 16 or 32 pages per signature.

Homebrew formula status: version, license, deprecation or disablement, install counts over 30, 90 and 365 days.

npm package adoption: downloads last week and month, plus trend within the month and a popularity band.

Match a misspelled or branded drug name to RxNorm: best candidates with RxCUI identifiers, names and match scores.

Metres per pixel, map scale (1:N) and tile width on the ground for a zoom level and latitude.

Sheet-metal bend allowance, outside setback, bend deduction and flat length from angle, radius, thickness and K-factor.

Compare realtime and batch API cost for a workload with your discount fraction, and the money saved by waiting.