1# About this documentation 2 3<!--introduced_in=v0.10.0--> 4<!-- type=misc --> 5 6Welcome to the official API reference documentation for Node.js! 7 8Node.js is a JavaScript runtime built on the [V8 JavaScript engine][]. 9 10## Contributing 11 12Report errors in this documentation in [the issue tracker][]. See 13[the contributing guide][] for directions on how to submit pull requests. 14 15## Stability index 16 17<!--type=misc--> 18 19Throughout the documentation are indications of a section's stability. Some APIs 20are so proven and so relied upon that they are unlikely to ever change at all. 21Others are brand new and experimental, or known to be hazardous. 22 23The stability indices are as follows: 24 25> Stability: 0 - Deprecated. The feature may emit warnings. Backward 26> compatibility is not guaranteed. 27 28<!-- separator --> 29 30> Stability: 1 - Experimental. The feature is not subject to 31> [Semantic Versioning][] rules. Non-backward compatible changes or removal may 32> occur in any future release. Use of the feature is not recommended in 33> production environments. 34 35<!-- separator --> 36 37> Stability: 2 - Stable. Compatibility with the npm ecosystem is a high 38> priority. 39 40<!-- separator --> 41 42> Stability: 3 - Legacy. The feature is no longer recommended for use. While it 43> likely will not be removed, and is still covered by semantic-versioning 44> guarantees, use of the feature should be avoided. 45 46Use caution when making use of Experimental features, particularly within 47modules. Users may not be aware that experimental features are being used. 48Bugs or behavior changes may surprise users when Experimental API 49modifications occur. To avoid surprises, use of an Experimental feature may need 50a command-line flag. Experimental features may also emit a [warning][]. 51 52## Stability overview 53<!-- STABILITY_OVERVIEW_SLOT_BEGIN --> 54| API | Stability | 55| --- | --------- | 56| [assert](assert.html) | (2) Stable | 57| [async_hooks](async_hooks.html) | (1) Experimental | 58| [buffer](buffer.html) | (2) Stable | 59| [child_process](child_process.html) | (2) Stable | 60| [cluster](cluster.html) | (2) Stable | 61| [console](console.html) | (2) Stable | 62| [crypto](crypto.html) | (2) Stable | 63| [dgram](dgram.html) | (2) Stable | 64| [diagnostics_channel](diagnostics_channel.html) | (1) Experimental | 65| [dns](dns.html) | (2) Stable | 66| [domain](domain.html) | (0) Deprecated | 67| [fs](fs.html) | (2) Stable | 68| [http](http.html) | (2) Stable | 69| [http/2](http2.html) | (2) Stable | 70| [https](https.html) | (2) Stable | 71| [inspector](inspector.html) | (2) Stable | 72| [module](modules.html) | (2) Stable | 73| [os](os.html) | (2) Stable | 74| [path](path.html) | (2) Stable | 75| [performance_measurement_apis](perf_hooks.html) | (2) Stable | 76| [punycode](punycode.html) | (0) Deprecated | 77| [querystring](querystring.html) | (3) Legacy | 78| [readline](readline.html) | (2) Stable | 79| [repl](repl.html) | (2) Stable | 80| [stream](stream.html) | (2) Stable | 81| [string_decoder](string_decoder.html) | (2) Stable | 82| [timers](timers.html) | (2) Stable | 83| [tls_(ssl)](tls.html) | (2) Stable | 84| [trace_events](tracing.html) | (1) Experimental | 85| [tty](tty.html) | (2) Stable | 86| [url](url.html) | (2) Stable | 87| [util](util.html) | (2) Stable | 88| [vm](vm.html) | (2) Stable | 89| [webassembly_system_interface_(wasi)](wasi.html) | (1) Experimental | 90| [worker_threads](worker_threads.html) | (2) Stable | 91| [zlib](zlib.html) | (2) Stable | 92<!-- STABILITY_OVERVIEW_SLOT_END --> 93 94## JSON output 95<!-- YAML 96added: v0.6.12 97--> 98 99Every `.html` document has a corresponding `.json` document. This is for IDEs 100and other utilities that consume the documentation. 101 102## System calls and man pages 103 104Node.js functions which wrap a system call will document that. The docs link 105to the corresponding man pages which describe how the system call works. 106 107Most Unix system calls have Windows analogues. Still, behavior differences may 108be unavoidable. 109 110[Semantic Versioning]: https://semver.org/ 111[V8 JavaScript engine]: https://v8.dev/ 112[the contributing guide]: https://github.com/nodejs/node/blob/HEAD/CONTRIBUTING.md 113[the issue tracker]: https://github.com/nodejs/node/issues/new 114[warning]: process.md#process_event_warning 115