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Application (sails)

The sails application object contains all relevant runtime state for a Sails application. By default it is exposed globally, but this behavior can be disabled, e.g. for use cases where multiple Sails app instances need to exist at once, or where globals are not an option. The application object can also always be accessed on an incoming request (req._sails).


The application object has a number of methods and properties which are useful. The officially supported methods on the sails object are covered by the other pages in this section. Here are a few of its most useful properties:


A dictionary of all loaded Sails models, indexed by their identity.

By default, a model's identity is the lowercased version of its filename, without the .js extension. For example, the default identity for a model loaded from api/models/PowerPuff.js would be powerpuff, and the model would be accessible via sails.models.powerpuff. A model's identity can be customized by setting an identity property in its module file.


The full set of configuration options for the Sails instance, loaded from a combination of environment variables, .sailsrc files, user-configuration files and defaults. See the configuration concepts section for a full overview of configuring Sails, and the configuration reference for details on individual options.


A set of convenience methods for low-level interaction with connected websockets. See the sails.sockets.* reference section for details.


A dictionary of all loaded Sails hooks, indexed by their identity. Use sails.hooks to access properties and methods of hooks you've installed to extend Sails; for example, by calling You can also use this dictionary to access the Sails core hooks, for advanced usage.

By default, a hook's identity is the lowercased version of its folder name, with any sails-hook- prefix removed. For example, the default identity for a hook loaded from node_modules/sails-hook-email would be email, and the hook hook would be accessible via An installed hook's identity can be changed via the installedHooks config property.

See the hooks concept documentation for more info about hooks.

How does it work?

An application instance is automatically created the first time you require('sails'). This is what is happening in the generated app.js file:

var sails = require('sails');

Creating a new application object (advanced)

Alternatively, if you are implementing something unconventional (e.g. writing tests for Sails core) where you need to create more than one Sails application instance in a process, you should not use the instance returned by require('sails'), as this can cause unexpected behavior. Instead, you should obtain application instances by using the Sails constructor:

var Sails = require('sails').constructor;
var sails0 = new Sails();
var sails1 = new Sails();
var sails2 = new Sails();

Each app instance (sails0, sails1, sails2) can be loaded/lifted separately, using different configuration.

For more on using Sails programatically, see the conceptual overview on programatic usage in Sails.

Is something missing?

If you notice something we've missed or could be improved on, please follow this link and submit a pull request to the sails-docs repo. Once we merge it, the changes will be reflected on the website the next time it is deployed.


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