Table of Contents

• About this Documentation

  • Contributing
  • Stability Index
  • JSON Output
  • Syscalls and man pages

About this Documentation#

Welcome to the official API reference documentation for Node.js!

Node.js is a JavaScript runtime built on the V8 JavaScript engine.

Contributing#

Report errors in this documentation in the issue tracker. See the contributing guide for directions on how to submit pull requests.

Stability Index#

Throughout the documentation are indications of a section's stability. Some APIs are so proven and so relied upon that they are unlikely to ever change at all. Others are brand new and experimental, or known to be hazardous.

The stability indices are as follows:

Use caution when making use of Experimental features, particularly within modules. End users may not be aware that experimental features are being used. Bugs or behavior changes may surprise end users when Experimental API modifications occur. To avoid surprises, use of an Experimental feature may need a command-line flag. Experimental features may also emit a warning.

JSON Output#

Every .html document has a corresponding .json document. This is for IDEs and other utilities that consume the documentation.

Syscalls and man pages#

System calls like open(2) and read(2) define the interface between user programs and the underlying operating system. Node.js functions which wrap a syscall, like fs.open(), will document that. The docs link to the corresponding man pages (short for manual pages) which describe how the syscalls work.

Most Unix syscalls have Windows equivalents, but behavior may differ on Windows relative to Linux and macOS. For an example of the subtle ways in which it's sometimes impossible to replace Unix syscall semantics on Windows, see Node.js issue 4760.