# origamitower/folktale

[not actively maintained!] A standard library for functional programming in JavaScript

Repository: https://github.com/origamitower/folktale
Canonical: https://ross.abutalabs.com/products/folktale
Homepage: https://folktale.origamitower.com/
Language: JavaScript
License: MIT
License Family: permissive
Topics: functional, javascript, algebraic-data-types
Archived: true
Last push: 2021-09-18T09:35:40+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4132, "days_push": 1810, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2029, forks 99 (observed 2026-08-28T04:06:07.058989+00:00)

## What it is
Folktale is a standard library for functional programming in JavaScript, providing algebraic data types like Maybe, Result, and Validation, lambda combinators, and Task for asynchronous operations. It is no longer actively maintained, as the maintainer has stopped working with JavaScript.

## Use cases
- handle errors without throw and try/catch using Maybe and Result
- compose asynchronous actions with automatic resource management using Task
- use monads and algebraic data types in JavaScript
- write modular functional JavaScript with combinators
- model optional values and validation in a type-safe way
- learn functional programming concepts in JavaScript

## When to choose
- you want mature, well-documented functional programming primitives in a JavaScript codebase
- you need Maybe/Result/Task abstractions and are comfortable maintaining the dependency yourself
- your project targets older browsers or Node versions, since Folktale backports to ES3/ES5 with shims

## When to avoid
- you need an actively maintained library with bug fixes and community support
- you are starting a new project and can use modern alternatives like fp-ts, Effect, or Sanctuary
- you need features beyond what version 2.3.2 offers, since development has stopped

## Facets
- artifact type: library
- maturity: abandoned
- function: error-handling, concurrency
- domain: programming-languages, developer-tools
- platform: browser, cross-platform
- tags: functional-programming, algebraic-data-types, monads, maybe, result, task, fantasy-land, not-maintained, algorithms, nodejs, javascript

## Member repositories
- origamitower/folktale (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:07.058989+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:59:38.390643+00:00, confidence not recorded.
  - readme: https://github.com/origamitower/folktale (fetched 2026-08-28T04:06:07.058989+00:00, sha de6396ff61ce)
  - homepage: https://folktale.origamitower.com/ (fetched 2026-08-29T10:39:52.866717+00:00, sha 1d15667e3013)
  - site_page: https://folktale.origamitower.com/docs/v2.3.0 (fetched 2026-08-29T10:39:52.875888+00:00, sha ffe8cb6fd417)
  - site_page: https://folktale.origamitower.com/docs/support (fetched 2026-08-29T10:39:52.877804+00:00, sha a422944f3727)
  - site_page: https://folktale.origamitower.com/docs/v2.3.0/release-notes (fetched 2026-08-29T10:39:52.879695+00:00, sha 0c2d27d81d3c)
  - site_page: https://folktale.origamitower.com/docs/v2.3.0/download (fetched 2026-08-29T10:39:52.881952+00:00, sha 69f996c6981a)
  - site_page: https://folktale.origamitower.com/docs/support/bugs (fetched 2026-08-29T10:39:52.884052+00:00, sha 950de3961e9f)
  - site_page: https://folktale.origamitower.com/docs/support/feature-request (fetched 2026-08-29T10:39:52.886447+00:00, sha aedd50f192cd)
  - site_page: https://folktale.origamitower.com/docs/v2.3.0/contributing (fetched 2026-08-29T10:39:52.888304+00:00, sha 253fc6a5eae7)
  - registry_npm: https://registry.npmjs.org/folktale (fetched 2026-08-29T10:39:52.890121+00:00, sha 9a2204c2748e)
- Data as of 2026-08-30T08:39:29.467469+00:00.