Requests and Responses

The Strapi back end server is based on Koa. When you send requests through the REST API, a context object (ctx) is passed to every element of the Strapi back end (e.g., policies, controllers, services).

ctx includes 3 main objects:

• ctx.request for information about the request sent by the client making an API request,
• ctx.state for information about the state of the request within the Strapi back end,
• and ctx.response for information about the response that the server will return.

Tip

The request's context can also be accessed from anywhere in the code with the strapi.requestContext function.

Info

In addition to the concepts and parameters described in the following documentation, you might find additional information in the Koa request documentation, Koa Router documentation and Koa response documentation.

The diagram represents a simplified version of how a request travels through the Strapi back end, with requests and responses highlighted. The backend customization introduction page includes a complete, interactive diagram.

ctx.request

The ctx.request object contains the following parameters:

Parameter	Description	Type
ctx.request.body	Parsed version of the body.	Object
ctx.request.files	Files sent with the request.	Array
ctx.request.headers	Headers sent with the request.	Object
ctx.request.host	Host part of the URL, including the port.	String
ctx.request.hostname	Host part of the URL, excluding the port.	String
ctx.request.href	Complete URL of the requested resource, including the protocol, domain, port (if specified), path, and query parameters.	String
ctx.request.ip	IP of the person sending the request.	String
ctx.request.ips	When X-Forwarded-For is present and app.proxy is enabled, an array of IPs is returned, ordered from upstream to downstream. For example if the value were "client, proxy1, proxy2", you would receive the ["client", "proxy1", "proxy2"] array.	Array
ctx.request.method	Request method (e.g., GET, POST).	String
ctx.request.origin	URL part before the first /.	String
ctx.request.params	Parameters sent in the URL. For example, if the internal URL is /restaurants/:id, whatever you replace :id in the real request becomes accessible through ctx.request.params.id.	Object
ctx.request.path	Path of the requested resource, excluding the query parameters.	String
ctx.request.protocol	Protocol being used (e.g., https or http).	String
ctx.request.query	Strapi-specific query parameters.	Object
ctx.request.subdomains	Subdomains included in the URL. For example, if the domain is tobi.ferrets.example.com, the value is the following array: ["ferrets", "tobi"].	Array
ctx.request.url	Path and query parameters of the requested resource, excluding the protocol, domain, and port.	String

Differences between protocol, origin, url, href, path, host, and hostname :

Given an API request sent to the https://example.com:1337/api/restaurants?id=123 URL, here is what different parameters of the ctx.request object return:

Parameter	Returned value
ctx.request.href	https://example.com:1337/api/restaurants?id=123
ctx.request.protocol	https
ctx.request.host	localhost:1337
ctx.request.hostname	localhost
ctx.request.origin	https://example.com:1337
ctx.request.url	/api/restaurants?id=123
ctx.request.path	/api/restaurants

ctx.request.query

ctx.request provides a query object that gives access to Strapi query parameters. The following table lists available parameters with a short description and a link to the relevant REST API documentation section (see REST API parameters for more information):

Parameter	Description	Type
ctx.request.query ctx.query	The whole query object.	Object
ctx.request.query.sort	Parameters to sort the response	String or Array
ctx.request.query.filters	Parameters to filter the response	Object
ctx.request.query.populate	Parameters to populate relations, components, or dynamic zones	String or Object
ctx.request.query.fields	Parameters to select only specific fields to return with the response	Array
ctx.request.query.pagination	Parameter to page through entries	Object
ctx.request.query.publicationState	Parameter to select the Draft & Publish state	String
ctx.request.query.locale	Parameter to select one or multiple locales	String or Array

ctx.state

The ctx.state object gives access to the state of the request within the Strapi back end, including specific values about the user, authentication, route:

Parameter	Description	Type
ctx.state.isAuthenticated	Returns whether the current user is authenticated in any way.	Boolean

ctx.state.user

The ctx.state.user object gives access to information about the user performing the request and includes the following parameters:

Parameter	Description	Type
ctx.state.user	User's information. Only one relation is populated.	Object
ctx.state.user.role	The user's role	Object

ctx.state.auth

The ctx.state.auth object gives access to information related to the authentication and includes the following parameters:

Parameter	Description	Type
ctx.state.auth.strategy	Information about the currently used authentication strategy (Users & Permissions plugin or API tokens)	Object
ctx.state.auth.strategy.name	Name of the currently used strategy	String
ctx.state.auth.credentials	The user's credentials	String

ctx.state.route

The ctx.state.route object gives access to information related to the current route and includes the following parameters:

Parameter	Description	Type
ctx.state.route.method	Method used to access the current route.	String
ctx.state.route.path	Path of the current route.	String
ctx.state.route.config	Configuration information about the current route.	Object
ctx.state.route.handler	Handler (controller) of the current route.	Object
ctx.state.route.info	Additional information about the current route, such as the apiName and the API request type.	Object
ctx.state.route.info.apiName	Name of the used API.	String
ctx.state.route.info.type	Type of the used API.	String

ctx.response

The ctx.response object gives access to information related to the response that the server will return and includes the following parameters:

Parameter	Description	Type
ctx.response.body	Body of the response.	Any
ctx.response.status	Status code of the response.	Integer
ctx.response.message	Status message of the response. By default, response.message is associated with response.status.	String
ctx.response.header ctx.response.headers	Header(s) sent with the response.	Object
ctx.response.length	Content-Length header value as a number when present, or deduces it from ctx.body when possible; otherwise, returns undefined.	Integer
ctx.response.redirect ctx.response.redirect(url, [alt])	Performs a 302 redirect to the URL. The string "back" is special-cased to provide Referrer support; when Referrer is not present, alt or "/" is used. Example: ctx.response.redirect('back', '/index.html');	Function
ctx.response.attachment ctx.response.attachment([filename], [options])	Sets Content-Disposition header to "attachment" to signal the client to prompt for download. Optionally specify the filename of the download and some options.	Function
ctx.response.type	Content-Type header, void of parameters such as "charset".	String
ctx.response.lastModified	Last-Modified header as a Date, if it exists.	DateTime
ctx.response.etag	Sets the ETag of a response including the wrapped "s. There is no corresponding response.etag getter.	String

Accessing the request context anywhere

Strapi exposes a way to access the current request context from anywhere in the code (e.g. lifecycle functions).

You can access the request as follows:

const ctx = strapi.requestContext.get();

You should only use this inside of functions that will be called in the context of an HTTP request.

// correct

const service = {
  myFunction() {
    const ctx = strapi.requestContext.get();
    console.log(ctx.state.user);
  },
};

// incorrect
const ctx = strapi.requestContext.get();

const service = {
  myFunction() {
    console.log(ctx.state.user);
  },
};

Example:

./api/test/content-types/article/lifecycles.js

module.exports = {
  beforeUpdate() {
    const ctx = strapi.requestContext.get();

    console.log('User info in service: ', ctx.state.user);
  },
};

Note

Strapi uses a Node.js feature called AsyncLocalStorage to make the context available anywhere.