> For the complete documentation index, see [llms.txt](https://feathersjs-mongoose.gitbook.io/feathers-mongoose-casl/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://feathersjs-mongoose.gitbook.io/feathers-mongoose-casl/master/docs/start-new-project-1/update-app.hook.md).

# App hooks

feathers-mongoose-casl hooks We need to set global hooks,

these hooks will run before and after each query hook.authenticate This is wrapper of @feathersjs/authentication - Feathers local, token, and OAuth authentication over REST and Websockets using JSON Web Tokens (JWT) with PassportJS.

**hooks.validateAbilities** This is a wrapper of Casl, in this hook, we will define abilities and block client without the ability to run this request Casl will add to mongoose query object a relevant key value before making the request, and validate Abilities will remove fields from user request by id abilities

**hooks.validateSchema** This hook will use JOI to validate request data follow the scheme

**hooks.sanitizedData** This hook will remove data from response follow the user abilities

**hook.errorHandler** to make sure that errors get cleaned up before they go back to the client

## Open src\app.hooks.js and paste this

{% code title="src\app.hooks.js" %}

```javascript
Open src\app.hooks.js and paste this
const log = require('./hooks/log');
const {hooks} = require('feathers-mongoose-casl');
​
module.exports = {
  before: {
    all: [
      log(),
      hooks.authenticate, // Check user token(JWT) and get user from DB, user will be found at hook.params.user 
      hooks.validateAbilities // Check user abilities (CASL) 
    ],
    find: [],
    get: [],
    create: [hooks.validateSchema], // validate Schema with JOI before create
    update: [hooks.validateSchema], // validate Schema with JOI before update
    patch: [hooks.validateSchema],// validate Schema with JOI before patch
    remove: []
  },
​
  after: {
    all: [ log(),
      hooks.sanitizedData, // Remove protected fields(CASL rules fields) from response
    ],
    find: [],
    get: [],
    create: [],
    update: [],
    patch: [],
    remove: []
  },
​
  error: {
    all: [ log(), hooks.errorHandler() ], // errorHandler - make sure that errors get cleaned up before they go back to the client
    find: [],
    get: [],
    create: [],
    update: [],
    patch: [],
    remove: []
  }
};
```

{% endcode %}

```
git add .
git commit -m "Add feathers-mongoose-casl authentication and authorization hooks"
```