# tc39/proposal-pipeline-operator

A proposal for adding a useful pipe operator to JavaScript.

Repository: https://github.com/tc39/proposal-pipeline-operator
Canonical: https://ross.abutalabs.com/products/proposal-pipeline-operator
Homepage: http://tc39.github.io/proposal-pipeline-operator/
Language: HTML
License: BSD-3-Clause
License Family: permissive
Topics: javascript, tc39, proposal, pipeline, operator, syntax
Last push: 2023-11-30T23:28:19+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 3950, "days_push": 1007, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 7904, forks 107 (observed 2026-08-28T04:10:09.381075+00:00)

## What it is
A TC39 Stage 2 proposal and formal specification for adding a Hack-style pipe operator (|>) to JavaScript, enabling left-to-right function application instead of deep nesting. The repository hosts the explainer, specification, and history, with an accompanying Babel plugin available for transpilation.

## Use cases
- add a pipe operator to javascript
- avoid deeply nested function calls in js
- read the tc39 pipeline operator proposal
- try the javascript pipe operator with babel
- understand hack-style pipelines in ecmascript
- follow the status of the js pipeline operator proposal

## When to choose
- you want to track or contribute to the standardization of the pipe operator in JavaScript
- you need the formal specification text for the proposed |> operator
- you want to experiment with pipe syntax today via the Babel plugin

## When to avoid
- you need a runnable library or tool rather than a language proposal document
- you cannot use a transpiler like Babel and need the feature in shipping JavaScript engines
- you want a stable, finalized ECMAScript feature - this proposal is still at Stage 2

## Facets
- artifact type: learning-resource
- maturity: active
- function: programming-language
- domain: programming-languages, web-development, frontend, documentation
- platform: browser
- tags: tc39, ecmascript-proposal, pipe-operator, javascript-syntax, specification, stage-2, babel-plugin, nodejs, web-server

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

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:09.381075+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 2026-08-29T17:33:23.624637+00:00, confidence not recorded.
  - readme: https://github.com/tc39/proposal-pipeline-operator (fetched 2026-08-28T04:10:09.381075+00:00, sha 5fcd1adc6588)
  - homepage: http://tc39.github.io/proposal-pipeline-operator/ (fetched 2026-08-29T08:30:03.099617+00:00, sha 59cb79b05750)
- Data as of 2026-08-30T08:39:29.467469+00:00.