Synchronous function​

module.exports={
register(){
// some sync code
},
bootstrap(){
// some sync code
},
destroy(){
// some sync code
}
};

exportdefault{
register(){
// some sync code
},
bootstrap(){
// some sync code
},
destroy(){
// some sync code
}
};

Asynchronous function​

module.exports={
asyncregister(){
// some async code
},
asyncbootstrap(){
// some async code
},
asyncdestroy(){
// some async code
}
};

exportdefault{
asyncregister(){
// some async code
},
asyncbootstrap(){
// some async code
},
asyncdestroy(){
// some async code
}
};

Function returning a promise​

module.exports={
register(){
returnnewPromise(/* some code */);
},
bootstrap(){
returnnewPromise(/* some code */);
},
destroy(){
returnnewPromise(/* some code */);
}
};

exportdefault{
register(){
returnnewPromise(/* some code */);
},
bootstrap(){
returnnewPromise(/* some code */);
},
destroy(){
returnnewPromise(/* some code */);
}
};

Register​

Theregister lifecycle function, found in./src/index.js (or in./src/index.ts), is an asynchronous function that runs before the application is initialized.It can be used to:

• extend plugins
• extendcontent-types programmatically
• load someenvironment variables
• register acustom field that would be used only by the current Strapi application,
• register acustom provider for the Users & Permissions plugin.

register() is the very first thing that happens when a Strapi application is starting. This happensbefore any setup process and you don't have any access to database, routes, policies, or any other backend server elements within theregister() function.

Bootstrap​

Thebootstrap lifecycle function, found in./src/index.js (or in./src/index.ts), is called at every server start.

It can be used to:

• create an admin user if there isn't one
• fill the database with some necessary data
• declare custom conditions for theRole-Based Access Control (RBAC) feature

Thebootstrapi() function is runbefore the back-end server starts butafter the Strapi application has setup, so you have access to anything from thestrapi object.

Destroy​

Thedestroy function, found in./src/index.js (or in./src/index.ts), is an asynchronous function that runs before the application gets shut down.

It can be used to gracefully:

• stopservices that are running
• clean up plugin actions (e.g. close connections, remove listeners, etc.)