docs/_includes/api/api_overview.html

{% include anchor.html title="API overview" hash="overview" %}

PouchDB has an asynchronous API, supporting both [callbacks](http://docs.nodejitsu.com/articles/getting-started/control-flow/what-are-callbacks) and [promises][promise].

Most of the API is exposed as:

{% highlight js %}
db.doSomething(args..., [options], [callback])
{% endhighlight %}

… where both the `options` and `callback` are optional.

Callbacks use the standard Node.js idiom of:

{% highlight js %}
function(error, result) { /* ... */ }
{% endhighlight %}

… where the `error` will be undefined if there's no error.

If you don't specify a `callback`, then the API returns a [promise][]. In [supported browsers](http://caniuse.com/#feat=promises), native promises are used, falling back to the minimal library [lie][] as needed. In Node.js, promises come from [Bluebird][].

For more info, check out the [guide to asynchronous code](/guides/async-code.html).

[promise]: https://www.promisejs.org/
[lie]: https://github.com/calvinmetcalf/lie
[bluebird]: https://github.com/petkaantonov/bluebird
[event emitter]: http://nodejs.org/api/events.html#events_class_events_eventemitter