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This is the home of the 4.x version. Upgrading from 3.x? See the Migration guide. The home for 2.x is here.

stream-chain builds object-processing pipelines from plain functions, generators, and existing streams — handling backpressure for you — on Node streams, Web streams, or neither. This page routes you to the right doc; for the 30-second pitch, see the README.

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Start here

New to stream-chain? Read in this order, then dip into the reference sections below:

1. Concepts — the model (one input → zero-to-many outputs), why streams, and how performance shaped the design.
2. Intro by examples — those concepts as runnable pipelines; the quickest way to see how it feels.
3. Performance — once it works, how to keep it fast and how to package reusable components.

API

• chain() — the heart of the package (imported as stream-chain). Choose a substrate by import path:
  • stream-chain / stream-chain/node — Node streams (default).
  • stream-chain/web — native Web streams; browser-safe.
  • stream-chain/core — substrate-free async iterables; the leanest option.
• Transducers — compose functions into one fused stage:
  • gen() — async generator; the memory-flat default.
  • fun() — function returning a batch; faster on sync pipelines, but holds outputs in memory (explicit import).
• Adapters — wrap a function as a standalone stream:
  • asStream() — Node Duplex.
  • asWebStream() — Web {readable, writable} pair.
• defs — the special values (none, stop, many, finalValue, flushable) and stream type guards.

I/O and utilities

• JSONL — batteries-included object I/O: parser / stringer for both substrates, plus the fused parseFile / stringerToFile file-edge composites.
• utils — the helper catalog: slicing (take / skip / …), folding (fold / scan / reduceStream), stream adapters (readableFrom, …), line / UTF-8 / batch helpers, block file I/O, and the pipe / drain drivers.
• streamPuller / webStreamPuller — consume a Node Readable / Web ReadableStream as a non-destructive async iterator.

Tuning and internals

For when it already works and you want more speed or more leverage:

• highWaterMark — tuning flow and backpressure.
• Benchmarks — how performance is measured, and how to run them.
• Typed streams — the TypeScript machinery behind pipeline I/O types.

Reference

• Release notes — the changelog.