The functional core of agentic AI

An Eslint plugin to help enforce functional principles and increase the 'functional core' of your code base.

A standalone, lawful functional core: Maybe, Either, match, dispatch tables, curry, and composition. Zero dependencies.

Production‑ready ESLint plugin that suggests corrections for typos in TypeScript/JavaScript code. Built with Functional Core / Imperative Shell and Effect‑TS.

The pure functional core of Vár: parser, matcher, planner, executor, AST, diagnostics, and the return-based comparison engine. Pure functions over immutable data — no globals, no I/O, no side effects.

A function-based version of the JavaScript standard library plus additional awesome functions

A **CSS Color Module 4** toolkit: parse, convert, serialize, gamut-map, interpolate, and analyze colors. A pure, tree-shakeable functional core with an ergonomic, **Temporal-shaped** immutable `Color` class on top.

Oxlint rules for Effect-TS — enforce a pure functional core and imperative shell: ban classes and string errors, forbid native Date/Promise/timers in Effect, require pipeable composition.

traverse and transform objects by visiting every node on a recursive walk

Pure functional core for clinical research form (CRF / REDCap) domain logic with Effect

Accessibility engine for automated Web UI testing

Functional Core, Imperative Shell analyzer for TypeScript codebases

JavaScript's functional programming helper library.

Functional core for developing web games

The missing standard library for TypeScript, for writing production-grade software.

Use space and slash separated color notation in CSS

A fully persistent balanced binary search tree

A practical functional library for JavaScript programmers.

Pure functional core for KERI: CESR encoding, SAID computation, KEL/TEL/ACDC operations, validation, signing primitives, canonical data, and threshold logic. No I/O, no storage, no side effects — runs in any JavaScript runtime (browser, Node.js, Bun, Clou

ESLint rules to promote functional programming in TypeScript.