# ReactiveX/IxJS

The Interactive Extensions for JavaScript

Repository: https://github.com/ReactiveX/IxJS
Canonical: https://ross.abutalabs.com/products/ixjs
Homepage: https://reactivex.io/IxJS/
Language: TypeScript
License: MIT
License Family: permissive
Last push: 2025-05-13T19:41:55+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 21, release rhythm 8, longevity 100
- inputs: {"age_days": 3845, "days_push": 477, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1411, forks 74 (observed 2026-08-28T04:04:38.964336+00:00)

## What it is
IxJS is a TypeScript library that brings Array#extras-style combinators like map, filter, and reduce to synchronous and asynchronous iterables, generators, and async generators. It serves as the pull-based counterpart to RxJS, unifying query composition over both sync and async collections.

## Use cases
- compose and query async iterables with map/filter/reduce
- process streams of data pulled at the consumer's pace
- unify synchronous and asynchronous collection handling in JavaScript
- apply LINQ-style operators to generators
- handle I/O streams with backpressure-friendly pull semantics
- chain operators on async generators in Node.js

## When to choose
- you need LINQ-like composition over iterables or async iterables
- your data is pull-based (I/O, file reads, paginated APIs) rather than push-based events
- you want a TypeScript-typed operator pipeline for generators
- you already use RxJS but need the pull-based counterpart

## When to avoid
- you need push-based event streams where the producer controls the rate - use RxJS instead
- you only work with plain arrays and native Array methods suffice
- you need a full reactive streams library with schedulers and subjects

## Facets
- artifact type: library
- maturity: active
- function: serialization, streaming, concurrency, developer-tools
- domain: developer-tools, web-development
- platform: browser, cross-platform
- tags: iterables, async-iterables, generators, linq, pull-based-streams, functional-programming, rxjs-companion, algorithms, real-time, nodejs, javascript

## Member repositories
- ReactiveX/IxJS (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:38.964336+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 2026-08-30T04:38:22.869011+00:00, confidence not recorded.
  - readme: https://github.com/ReactiveX/IxJS (fetched 2026-08-28T04:04:38.964336+00:00, sha 4b747bc4c909)
  - homepage: https://reactivex.io/IxJS/ (fetched 2026-08-29T11:51:38.403601+00:00, sha b6a0cd2f759d)
- Data as of 2026-08-30T08:39:29.467469+00:00.