JavaScript Engine

Starting from version 0.8.6, multiple JavaScript engines are supported. To specify a particular engine, use the js_engine directive available for both the http and stream. By default, the njs engine is used.

njs engine

The njs engine is deprecated since 1.0.0; new code should use the QuickJS engine instead.

njs is an embeddable JavaScript engine developed as a part of the njs module. See the Сompatibility section for details.

QuickJS engine

QuickJS is a lightweight, embeddable JavaScript engine that supports the ES2023 specification, including features as modules, asynchronous generators, proxies and BigInt.

Since version 0.8.6, a drop-in replacement for njs/nginx objects has been introduced to ensure compatibility with the njs engine, with the following exceptions:

• njs-specific API: njs.dump(), console.dump().
• deprecated API: require(), use the import statement instead.
• js_preload_object directive for http and stream.

njs built-in modules status:

• buffer: since 0.8.6.
• crypto: since 0.8.10.
• fs: since 0.8.9.
• querystring: since 0.8.10.
• WebCrypto: since 0.8.10.
• xml: since 0.8.10.
• zlib: since 0.8.5.

njs built-in objects status:

• process: since 0.8.8.
• TextDecoder: since 0.8.10.
• TextEncoder: since 0.8.10.

nginx built-in objects status:

• ngx.fetch: since 0.9.1.
• shared dictionary: since 0.8.8.