engine.xml

<?xml version="1.0"?>

<!--
  Copyright (C) Nginx, Inc.
  -->

<!DOCTYPE article SYSTEM "../../../../dtd/article.dtd">

<article name="JavaScript Engine"
        link="/en/docs/njs/engine.html"
        lang="en"
        rev="6"
        toc="no">

<section>

<para>
Starting from version <link doc="changes.xml" id="njs0.8.6">0.8.6</link>,
multiple JavaScript engines are supported.
To specify a particular engine, use the <literal>js_engine</literal> directive
available for both the
<link doc="../http/ngx_http_js_module.xml" id="js_engine">http</link>
and
<link doc="../stream/ngx_stream_js_module.xml" id="js_engine">stream</link>.
By default, the njs engine is used.
</para>

</section>


<section id="njs_engine" name="njs engine">

<para>
<note>
The njs engine is deprecated
since <link doc="changes.xml" id="njs1.0.0">1.0.0</link>;
new code should use the
<link id="quickjs_engine">QuickJS</link> engine instead.
</note>
</para>

<para>
njs is an embeddable JavaScript engine
developed as a part of the njs module.
See the <link doc="compatibility.xml">Сompatibility</link> section for details.
</para>

</section>


<section id="quickjs_engine" name="QuickJS engine">

<para>
<link url="https://bellard.org/quickjs/">QuickJS</link> is a lightweight,
embeddable JavaScript engine that supports
the <link url="https://tc39.es/ecma262/2023/">ES2023</link> specification,
including features as modules, asynchronous generators, proxies and BigInt.
</para>

<para>
Since version <link doc="changes.xml" id="njs0.8.6">0.8.6</link>,
a drop-in replacement for
<link doc="reference.xml">njs/nginx objects</link>
has been introduced
to ensure compatibility with the njs engine, with the following exceptions:

<list type="bullet">

<listitem>
njs-specific API:
<link doc="reference.xml" id="njs_dump"><literal>njs.dump()</literal></link>,
<literal>console.dump()</literal>.
</listitem>

<listitem>
deprecated API:
<literal>require()</literal>,
use the <literal>import</literal> statement instead.
</listitem>

<listitem>
<literal>js_preload_object</literal> directive for
<link doc="../http/ngx_http_js_module.xml" id="js_preload_object">http</link>
and
<link doc="../stream/ngx_stream_js_module.xml" id="js_preload_object">stream</link>.
</listitem>

</list>

</para>

<para>
njs built-in modules status:

<list type="bullet">

<listitem>
<link doc="reference.xml" id="buffer"><literal>buffer</literal></link>:
since <link doc="changes.xml" id="njs0.8.6">0.8.6</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="crypto"><literal>crypto</literal></link>:
since <link doc="changes.xml" id="njs0.8.10">0.8.10</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="njs_api_fs"><literal>fs</literal></link>:
since <link doc="changes.xml" id="njs0.8.9">0.8.9</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="querystring"><literal>querystring</literal></link>:
since <link doc="changes.xml" id="njs0.8.10">0.8.10</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="builtin_crypto"><literal>WebCrypto</literal></link>:
since <link doc="changes.xml" id="njs0.8.10">0.8.10</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="xml"><literal>xml</literal></link>:
since <link doc="changes.xml" id="njs0.8.10">0.8.10</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="zlib"><literal>zlib</literal></link>:
since <link doc="changes.xml" id="njs0.8.5">0.8.5</link>.
</listitem>

</list>

</para>

<para>
njs built-in objects status:

<list type="bullet">

<listitem>
<link doc="reference.xml" id="process"><literal>process</literal></link>:
since <link doc="changes.xml" id="njs0.8.8">0.8.8</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="textdecoder"><literal>TextDecoder</literal></link>:
since <link doc="changes.xml" id="njs0.8.10">0.8.10</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="textencoder"><literal>TextEncoder</literal></link>:
since <link doc="changes.xml" id="njs0.8.10">0.8.10</link>.
</listitem>

</list>

</para>

<para>
nginx built-in objects status:

<list type="bullet">

<listitem>
<link doc="reference.xml" id="ngx_fetch"><literal>ngx.fetch</literal></link>:
since <link doc="changes.xml" id="njs0.9.1">0.9.1</link>.
</listitem>

<listitem>
<link doc="reference.xml" id="ngx_shared"><literal>shared dictionary</literal></link>:
since <link doc="changes.xml" id="njs0.8.8">0.8.8</link>.
</listitem>

</list>

</para>

</section>

</article>