@open-utility-tools/core

Framework-agnostic core logic extracted from Open Utility Tools — the pure, dependency-free building blocks behind the web app. No React, no DOM, zero runtime dependencies.

Scope. Every function here is isomorphic — it runs identically in the browser, Node ≥ 20, and Bun. Pure-TS tiers (text, math, color, data, time, web, generators, WebCrypto) are plain modules; raster image tools are WASM-backed by the bundled imaging crate and work the same in all three runtimes. This is being built out tool-by-tool from the app's ~1,000 tools. Landed: the pure tiers, the WASM image tools, and the full time category (63 tools, each with a golden test suite). The rest are extracted category-by-category via the same pipeline.

Per-tool subpaths

Every tool is importable on its own subpath — pull in exactly one:

import { calculateAge }     from '@open-utility-tools/core/time/age-calculator';
import { addBusinessDays }  from '@open-utility-tools/core/time/add-business-days';
import { parseCron }        from '@open-utility-tools/core/time/cron-parser';
import { convert }          from '@open-utility-tools/core/image/convert';

Install

npm install @open-utility-tools/core

Requires Node ≥ 20 (the crypto and generators entries use the global WebCrypto API).

Usage

Import a domain via its subpath (recommended — keeps bundles small):

import { cases, diffLines } from '@open-utility-tools/core/text';
import { convertUnit, evaluateExpression } from '@open-utility-tools/core/math';
import { parseColor, contrastRatio } from '@open-utility-tools/core/color';
import { csvToJson, jsonToYaml } from '@open-utility-tools/core/data';
import { parseCron, nextRuns } from '@open-utility-tools/core/time';
import { HTTP_STATUSES, MIME_TYPES } from '@open-utility-tools/core/web';
import { uuidV7, generatePassword } from '@open-utility-tools/core/generators';
import { signJwt, hotp } from '@open-utility-tools/core/crypto';

Or grab everything as namespaces from the root entry:

import { text, math, color } from '@open-utility-tools/core';
text.cases.kebab('Hello World'); // "hello-world"

Subpath exports

| Import | Contents | | --- | --- | | …/text | case conversion, line diff, line ops, markdown→html, morse | | …/math | safe expression eval, gcd/lcm/primes/stats, roman numerals, unit conversion | | …/color | hex/rgb/hsl/hsv/cmyk/oklch conversion, luminance, WCAG contrast | | …/data | CSV ↔ JSON, JSON → TypeScript, YAML ↔ JSON | | …/time | 5-field cron parse / explain / next-runs | | …/web | HTTP status code + MIME type reference tables | | …/generators | lorem ipsum, fake records, .gitignore templates, UUID/ULID/nanoid, passwords | | …/crypto | JWT signing, HOTP, base32 decode, base64url (WebCrypto) | | …/image | WASM-backed raster convert + probe (browser/Node/Bun) | | …/time/* | 63 date/time tools, each on its own subpath (age, durations, cron, ISO-8601, timezones, …) |

Notes

• Randomness. generators/lorem, fake, and gitignore use Math.random (not cryptographically secure). generators/ids, generators/password, and everything in crypto use globalThis.crypto and are suitable for secrets.
• ESM only. The package ships ES modules with type declarations.

License

MIT © Sai Kiran Reddy Uppula