Draft Beer API

Draft-beer dispense maths as an API, computed locally and deterministically — the CO₂ pressure and beer-line numbers a homebrewer, kegerator owner or bar sets a tap by. (This is the serving side; for ABV, gravity and IBU that is a homebrewing calculation.) The carbonation endpoint gives the regulator head pressure that holds a target carbonation at the serving temperature, from the standard volumes-temperature-pressure regression: 2.5 volumes of CO₂ at 38 °F needs about 11 psi, and colder beer holds the same carbonation at a lower pressure — British ales sit around 1.5–2.0 volumes, US ales 2.2–2.7, lagers and wheats higher. The balance endpoint sizes the beer line so the system pours a clean head instead of foaming or pouring slow: line length = (applied pressure − 0.5 × rise − residual) ÷ the line’s resistance per foot, where gravity adds about 0.5 psi per foot of lift and roughly 1 psi is left at the faucet — so 12 psi with no rise on 3/16-inch vinyl (≈3 psi/ft) wants about 3.7 feet, while narrower or wider tubing changes everything. Everything is computed locally and deterministically, so it is instant and private. Ideal for homebrew, kegerator, bar, brewery-taproom and beverage app developers, draft-system and troubleshooting tools, and hospitality software. Pure local computation — no key, no third-party service, instant. Dispense side only. Live, nothing stored. 2 compute endpoints.