# tc39/proposal-observable

Observables for ECMAScript

Repository: https://github.com/tc39/proposal-observable
Canonical: https://ross.abutalabs.com/products/proposal-observable
Homepage: https://tc39.github.io/proposal-observable/
Language: JavaScript
License Family: other
Last push: 2019-11-01T06:49:54+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4142, "days_push": 2497, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3103, forks 89 (observed 2026-08-28T04:07:43.687569+00:00)

## What it is
A TC39 stage-1 proposal introducing an Observable type to the ECMAScript standard library for modeling push-based asynchronous data streams like DOM events, timers, and sockets. The repository contains the specification draft and polyfill implementations rather than a production library.

## Use cases
- handle DOM event streams reactively in JavaScript
- understand how the Observable proposal works
- implement push-based async data streams
- standardize reactive stream protocol across platforms
- subscribe and unsubscribe from event streams with cleanup

## When to choose
- you want to follow or contribute to the ECMAScript Observable standardization effort
- you need a minimal spec-compliant Observable implementation to build on
- you're evaluating reactive stream APIs for a platform or library

## When to avoid
- you need a full-featured reactive library with operators like filter and map today - use RxJS instead
- you need something stable for production - the proposal is still stage 1 and inactive since 2019
- you need guaranteed future compatibility, since the proposal may change or be withdrawn

## Facets
- artifact type: learning-resource
- maturity: maintenance
- function: concurrency, developer-tools
- domain: programming-languages, web-development, frontend
- platform: browser
- tags: ecmascript-proposal, observables, reactive-programming, tc39, specification, push-based-streams, javascript, nodejs

## Member repositories
- tc39/proposal-observable (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:43.687569+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 2026-08-29T18:46:19.782411+00:00, confidence not recorded.
  - readme: https://github.com/tc39/proposal-observable (fetched 2026-08-28T04:07:43.687569+00:00, sha c0b2a99f3fa1)
  - homepage: https://tc39.github.io/proposal-observable/ (fetched 2026-08-29T09:42:23.422524+00:00, sha 389644074fb6)
- Data as of 2026-08-30T08:39:29.467469+00:00.