HTTP Client | IntelliJ IDEA Documentation

Create HTTP request files

You can work with HTTP requests either from scratch files or from physical files of the HTTP Request type. Each file can contain multiple requests, and you can create as many files as needed.

Scratch files can be used to test HTTP requests during development. Scratch files are not stored inside a project, so IntelliJ IDEA can modify them and add additional information about the request. When an HTTP request is executed from a scratch file, the link to the response output file is added below the request and at the top of the requests history file.

Create an HTTP request scratch file

Press Ctrl+Alt+Shift+Insert and select HTTP Request.

Physical files can be used for documenting, testing, and validating HTTP requests. Physical files are stored inside your project, and IntelliJ IDEA will not modify them. When an HTTP request is executed from a physical file, this file is not modified. Information about the executed request with the link to the response output file is added to the top of the requests history file.

Create a physical HTTP request file

In the File menu, point to New, and then click HTTP Request.

Move an HTTP request

You can use the Move refactoring F6 to move HTTP requests from scratches to physical files, as well as between physical files.

In the editor, place the caret at the request to be moved and do one of the following:
- From the main menu or the context menu, select Refactor | Move.
- Press Alt+Enter and select the Move HTTP Requests intention action.
- Press F6.
In the Move HTTP Requests dialog that opens, do the following:
1. In the Path field, choose one of the existing .http files from the list or click to locate the file.
  You can also type the full path to the file manually. If you specify the name of a non-existing file, a new file with the provided name will be created automatically.
2. In the Requests list, select the checkboxes next to the requests you want to move.

Compose HTTP requests

IntelliJ IDEA uses the HTTP request in Editor format, which provides a simple way to create, execute, and store information about HTTP requests. You can type them directly in the created HTTP request files using the following general syntax:

        ###
        Method Request-URI HTTP-Version
        Header-field: Header-value

        Request-Body
        

After the ### separator, you can enter any comments preceded by # or //.

To speed up composing HTTP requests, you can:

Click Tools | HTTP Client | Create Request in HTTP Client. If a request file is opened in the editor, this will add a request template to the opened file. Otherwise, this will create a new .http scratch file.
Click on top of the request's editor panel. In the popup menu, select the type of the request to add.

Alternatively, use live templates. In the editor, you can press Ctrl+J to view the list of available templates. For example, gtr expands to a simple GET request; mptr expands to a multipart/form-data POST request.

HTTP/2

Starting with version 2024.1, IntelliJ IDEA provides support for HTTP/2 in HTTP requests. You can specify the HTTP version after the URL part, for example:

GET https://example.org HTTP/2

If no version is specified, the HTTP Client attempts to use HTTP/2 for secure connections (and falls back to HTTP/1.1 if HTTP/2 negotiation fails) and HTTP/1.1 for non-secure connections.

Select HTTP version

After the request URL, put a white space and press Ctrl+Space or start typing HTTP.
From the completion list, select one of the suggested values:
- HTTP/1.1 to enforce the use of HTTP/1.1.
- HTTP/2 to enable the use of HTTP/2.
- HTTP/2 (Prior Knowledge) to send using HTTP/2 without HTTP/1.1 Upgrade. Use it if you know your server can handle HTTP/2 connections.

To get an overview of the HTTP Client features, you can explore the HTTP Requests Collection, which is a handful selection of composed requests.

Open a request from the HTTP Requests Collection

Click the Examples shortcut link on top of the request's editor panel.
In the popup menu, choose the HTTP Requests collection you wish to open:

Convert cURL requests

If you are working with cURL requests, you can convert between cURL requests and the HTTP request in Editor format.

Convert cURL to HTTP request

Paste the cURL request into an HTTP request file. IntelliJ IDEA will convert it to the HTTP request format and leave the original cURL request commented out for later reference.
Alternatively, click on top of the HTTP request editor panel and select Convert cURL to HTTP Request.
In the Convert cURL to HTTP Request dialog, type or paste the cURL request that you want to convert.

Consider the following example cURL request:

                curl 'https://httpbin.org/' -H 'Connection: keep-alive' -H 'Accept: text/html' -H 'Accept-Encoding:
                gzip, deflate' -H 'Accept-Language: en-US,en;q=0.9,es;q=0.8'
            

IntelliJ IDEA will convert it to the following:

                # curl 'http://httpbin.org/' -H 'Connection: keep-alive' -H 'Accept: text/html' -H 'Accept-Encoding: gzip, deflate' -H 'Accept-Language: en-US,en;q=0.9,es;q=0.8'
                GET http://httpbin.org/
                Connection: keep-alive
                Accept: text/html
                Accept-Encoding: gzip, deflate
                Accept-Language: en-US,en;q=0.9,es;q=0.8

                ###
            

The converter supports the following cURL options:

Option	Description
-X, --request	The request method to use.
-H, --header	The request header to include in the request.
-u, --user --basic --digest	The user's credentials to be provided with the request, and the authorization method to use.
-d, --data, --data-ascii --data-binary --data-raw --data-urlencode	The data to be sent in a POST request.
-F, --form	The multipart/form-data message to be sent in a POST request.
--url	The URL to fetch (mostly used when specifying URLs in a config file).
-i, --include	Defines whether the HTTP response headers are included in the output.
-v, --verbose	Enables the verbose operating mode.
-L, --location	Enables resending the request in case the requested page has moved to a different location.

Convert HTTP request to cURL

Place the caret at the HTTP request that you want to convert to cURL format.
Press Alt+Enter and select Convert to cURL and copy to clipboard.
Alternatively, you can click the Convert shortcut link on top of the HTTP request editor panel and select Convert HTTP Request Under Caret to cURL and Copy.

This will generate a cURL request based on the HTTP request and copy it to the clipboard.

Import Postman collections and environments

Postman collections is a way to group related HTTP requests together. In Postman, you can export collections as well as variables in JSON format. With the HTTP Client, you can import such files to IntelliJ IDEA to convert them to the respective .http and environment files.

Import Postman collections to HTTP Client

Export a collection from Postman. You can also export environment files if you want to use them in IntelliJ IDEA.
Import the file to IntelliJ IDEA in one of the following ways:
- If the exported file is in your project, right-click it and select Convert Collection to .http File.
- Open any .http file, click in the toolbar, and select Postman Collection.
- Press Ctrl+Shift+A, start typing Import from Postman Collection File, and select the corresponding action.
If you also want to import an environment file, select Attach environment and specify the file. It will be converted to the HTTP Client environment format, and this environment will be selected for the specified .http file.
In the window that appears, click Convert.

Generate requests using context action

You can quickly generate an HTTP request if you have a URL starting with http or https in your code string literals or in JSON, YAML, TOML, and Properties files.

Click a URL and press Alt+Enter.
In the context menu that opens, click Generate request in HTTP Client.
This will create a new GET HTTP request to the specified URL in the generated-requests.http scratch file.

Create requests from OpenAPI specifications

When working with OpenAPI Specification files, you can create HTTP requests to the specified endpoints.

Create an HTTP request to an endpoint

In an OpenAPI specification file, click in the editor gutter next to the endpoint definition.
Alternatively, open View | Tool Windows | Endpoints, right-click an endpoint, and select Generate Request in HTTP Client.

IntelliJ IDEA will create a new HTTP request and save it in the generated-requests.http scratch file.

If you want to quickly send a request to an endpoint and do not want to save it, you can use the HTTP Client tab in the Endpoints tool window.

IntelliJ IDEA provides completion for the request URL and for the request body (in JSON format) based on the available OpenAPI specifications. This applies not only to local, but also to remote specifications (add them in the IDE settings to enable completion).

Rename an endpoint and its usages

Use the Rename refactoring to rename the defined endpoint and its usages in HTTP requests simultaneously.

Do any of the following:
- In an OpenAPI specification file, place the caret at the endpoint's definition you want to rename.
- In an HTTP request file, place the caret at the URL path segment you want to rename.
Select Refactor | Rename from the main menu or the context menu, or press Shift+F6.
In the Rename dialog that opens, specify the new endpoint's name.
Preview and apply changes.

IntelliJ IDEA will rename the endpoint and its usages.

Use response handler and pre-request scripts

With response handler scripts, you can programmatically react to a received HTTP response. By using these scripts, you can automatically process the received data as well as validate it against the conditions that you specify. Response handler scripts are provided as a part of the request within the HTTP request file and are executed as soon as a response is received. To view the response handling examples, open the Requests with Authorization or Requests with Tests and Scripts requests collections.

With pre-request scripts, you can set variables used in HTTP requests.

Insert response handler scripts

You can insert a response handler script into your request in-place or by referring to an external file.

To insert the script in-place, prepend it with > and enclose it in {% %}:
GET host/api/test > {% // Response Handler Script ... %}
To insert the script from an external file, prepend it with >:
GET host/api/test > scripts/my-script.js

If there is any output from the response handler script (errors or output from client.log), it is shown in the Response Handler tab of the Services tool window when you run the request.

Insert pre-request scripts

You can insert a pre-request script into your request in-place or by referring to an external file.

To insert the script in-place, prepend it with < and enclose it in {% %}:
< {% request.variables.set("petName", "Bella") %} POST https://example.org/pets/{{petName}}
To insert the script from an external file, prepend it with <:
< scripts/my-script.js POST https://example.org/pets/{{petName}}

If there is any output from the pre-request script (errors or output from client.log), it is shown in the Pre-request Handler tab of the Services tool window when you run the request.

Import JavaScript code

Sometimes, you may need to use specific functionalities, such as variables or functions, from external files. For this, in pre-request and response handler scripts, you can use the regular ES6 import feature to access variables and functions defined in local JavaScript files.

Export the needed values from a JavaScript file. The HTTP Client supports export statements in the following formats:
export let name1, name2/*, … */; // also var export const name1 = 1, name2 = 2/*, … */; // also var, let export function functionName() { /* … */ } export { name1, /* …, */ nameN }; export { variable1 as name1, variable2 as name2, /* …, */ nameN }; export default expression; export default function functionName() { /* … */ } export default function () { /* … */ }
Import the needed values into your response handler or pre-request script. The HTTP Client supports import statements in the following formats:
import defaultExport from "module-name"; import * as name from "module-name"; import { export1 } from "module-name"; import { export1 as alias1 } from "module-name"; import { export1, export2 } from "module-name"; import { export1, export2 as alias2, /* … */ } from "module-name"; import defaultExport, { export1, /* … */ } from "module-name"; import defaultExport, * as name from "module-name"; import "module-name"; // side effect import
If you want to run some tests from an external file and do not need to import anything from them, you can use side effect import in your response handler script, for example import 'test-scripts/mytests'. This can be useful if you have common tests and want to reuse them in multiple requests while also keeping the ability to write (or import) individual tests for some requests.

Response handler scripts and pre-request scripts are written in JavaScript ECMAScript 6, with coding assistance and documentation handled by the bundled HTTP Pre-Request and Response Handler library. For in-place scripts, this functionality is enabled automatically. For external scripts, you need to enable it manually.

Enable JavaScript coding assistance for response handler and pre-request scripts

Press Ctrl+Shift+A (Find Action).
Type Use JavaScript Library, click the corresponding action, and, in the context menu that opens, select HTTP Pre-Request and Response Handler.

The HTTP Response Handler library exposes two objects to be used for composing response handler scripts:

The client object stores the session metadata, which can be modified inside the script. The client state is preserved until you close IntelliJ IDEA. Every variable saved in client.global as variable_name is accessible to subsequent HTTP requests as {{variable_name}}.
response holds information about the received response: its content type, status, response body, and so on.

To open the HTTP Response Handler library in the editor, place the caret at the library object and press Ctrl+B.

Response handler scripts can include tests, which lets you use the HTTP Client as a testing framework. To create a test, invoke the client.test(testName, function) method. Inside the test, you can assert a condition by invoking the client.assert(condition, message) method, for example:

                GET https://httpbin.org/status/200

                > {%
                    client.test("Request executed successfully", function() {
                        client.assert(response.status === 200, "Response status is not 200");
                    });
                %}
            

Navigate through .http file using the Structure tool window

If you have multiple requests in your .http file, the Structure tool window can be useful to quickly preview the file and navigate through it. The tool window also shows the request parts, such as headers, the request bodies, pre-request scripts, and response handler scripts.

Open the Structure tool window: View | Tools Windows | Structure.
Alternatively, press Alt+7.
In the Structure tool window, click an HTTP method or request name, or any part of the request.

You can also send requests from there by right-clicking it and selecting .

Execute HTTP requests

If you are going to test your own web service, make sure it is deployed and running.
If you have environments defined, select an environment in the Run with list on top of the request's editor panel.
In the gutter, click next to the request.

If you have multiple HTTP requests defined in an .http file, you can run all of them sequentially. To do this, click on top of the request's editor panel.

When a request is executed, IntelliJ IDEA automatically creates a dedicated temporary HTTP Request run/debug configuration for it. You can save it as a permanent run/debug configuration if necessary.

Open a request in the browser

You can open an HTTP request in the browser specified on the Web Browsers and Preview page of the Settings dialog (Ctrl+Alt+S) .

Press Alt+Enter and select the Open in web browser intention action.

Work with HTTP request run/debug configurations

When you execute an HTTP request from the editor, IntelliJ IDEA automatically creates a temporary run/debug configuration with the request parameters. A temporary run/debug configuration works the same way as a permanent run/debug configuration. You can change its settings using the Run/Debug Configuration dialog and optionally save it as permanent.

Modify an HTTP Request run/debug configuration

Do any of the following:
- In the editor, right-click a request and in the context menu, select Modify Run Configuration....
- Alternatively, go to Run | Edit Configurations in the main menu, and select the needed run/debug configuration in the HTTP Request list.
Change the needed configuration parameters:
- In the Environment list, select an environment that will define the set of environment variables used in the request.
- In the File field, provide the path to the HTTP request file. You can type the path manually and use path completion Ctrl+Space as you type, or click and select the required folder in the dialog that opens.
- If your request file contains multiple requests, in the Request list, choose the name of the request to execute.

Save a temporary HTTP Request run/debug configuration

In the Run/Debug Configuration selector, choose Save <configuration name>.
In the Run/Debug Configuration dialog, select the configuration and click .

Execute a request using a run/debug configuration

In the Run/Debug Configuration selector, select the desired run configuration. Then click on the main toolbar or press Shift+F10.
Press Alt+Shift+F10, select the desired run configuration from the list, and press Enter.

View responses from web services

When you execute an HTTP request, IntelliJ IDEA automatically saves the response into a separate file under the .idea/httpRequests/ directory. You can view the 50 most recently stored responses and navigate to the corresponding files using the requests history. If the request was executed from a scratch file, the link to its response output is also added below the original request:

View a received response

Switch to the Services tool window, which opens automatically as soon as a response is received.
By default, the server response is shown in the format specified in the request header via the content-type field. To have the response converted into another format, click and select Text, JSON, XML, or HTML.

If the response contains a binary file, this file is also saved under the .idea/httpRequests/ directory. If the response is an image, PDF or HTML file, you can preview them right in the IDE.

Preview the image the Services tool window:

Preview the PDF file the Services tool window. To disable showing PDF preview in the Services tool window, click and clear the Enable PDF preview inline option.

If the response is an HTML file, you can click Show Preview to preview it in the editor tab using the JCEF-based browser.

If you have a response handler script, the results of the tests executed as part of this script are displayed on the Tests tab of the Services tool window. You can click each of the tests to quickly navigate to the test source code in the corresponding response handler script.

The Tests tab of the Services tool window

If you subscribe to an event stream, IntelliJ IDEA displays events in the Services tool window. Here, you can also view the status of the client-server connection and terminate it by clicking . Depending on the content type (either text/event-stream or application/x-ndjson), the response will be formatted as plain text or newline-delimited JSON. You can write a response handler script to process each line of the event stream.

Redirecting stream events to a file is currently not supported.

Open a response file in the editor

Place the caret at the link to the response you want to open.
In the main menu, go to View | Jump to Source, or press Ctrl+B or F4

Alternatively, you can Ctrl+Click the response line.

Extract data from JSON response using JSONPath

The HTTP Client supports JSONPath queries, enabling you to parse and extract data from received JSON documents. To do this, use the following function in your response handler script:

jsonPath(ObjectToParse, JSONPathExpression)

Use the jsonPath live template to quickly insert this function.

After the request, in the response handler script part, start typing > jsonPath.
Press Enter to expand the live template and complete the JSONPath expression.
For example, this expression will retrieve and print the value of the title field of the first element within the slides array, which is a part of the slideshow object:
GET https://examples.http-client.intellij.net/json > {% client.log(jsonPath(response.body, "$.slideshow.slides[0].title",)) %}
Preview the obtained value in the Response Handler tab of the Services tool window.

Compare responses in a scratch file

When a request is executed from a scratch file, the link to the response output file is added below the original request.

Do any of the following:
- Place the caret at the link to the response file. Press Alt+Enter and select the Compare with <response name> intention action.
- Click in the gutter and select Compare with <response name> from the list:

Compare responses in the request history

When a request is executed from a physical file, the link to the response output is added to the requests history.

Place the caret at the link to the response file. In the main menu, go to View | Jump to Source, or press Ctrl+B or F4 to open this file in a new editor tab.
Go to View | Compare With in the main menu, or press Ctrl+D. IntelliJ IDEA will prompt you to open a response file from the httpRequests folder.
Select the response file you would like to compare the current file with and click Open.

The two response files will be opened in the Diff Viewer allowing you to compare their contents:

View request history

IntelliJ IDEA automatically saves the 50 recently executed requests into the http-requests-log.http file, which is stored on the project level under the .idea/httpRequests/ directory. With requests history, you can quickly navigate to a particular response as well as issue any request again. If a request is issued again from the request history, its execution information and the link to the response output are added to the top of the request history file.

Open request history

Click on top of the request's editor panel.
Select Tools | HTTP Client | Show HTTP Requests History from the main menu.

Redirect output to a custom file or directory

The HTTP Client can redirect output to a custom file or directory. It supports two operators for force and soft redirects:
- The >> operator always creates a new file, adding an -n suffix to a filename if the requested filename already exists.
- The >>! operator rewrites the file if it already exists.

Manage cookies

The cookies received through a response are automatically saved into the dedicated http-client.cookies file under the .idea/httpRequests/ directory. The number of cookies that can be saved is limited to 300. The name and value of a cookie are automatically included in each subsequent request to the URL that matches the domain and path specified for the cookie, provided that the expiry date has not been reached.

If you want a cookie to never expire, you can enter -1 as the date parameter. For example:

            # domain path name value date

            .example.com / userId 0x4d2 -1

If you want to set custom cookies in an HTTP request, you can use the Cookie header. Enter your cookies as a list of name=value pairs separated by a semicolon, for example:

            GET http://localhost:80/api
            Cookie: theme=dark; country=France
        

gRPC requests

The HTTP Client supports gRPC requests. For the HTTP Client to treat your requests as gRPC requests, start them with the GRPC keyword.

Based on a .proto file, IntelliJ IDEA provides completion for gRPC: all known gRPC services, unary and server-streaming methods of a particular server, and fields of accepted messages in the request body. If you don’t have a .proto file in your project, code completion can still be available if a server supports gRPC reflection, which provides HTTP clients with information about accessible services.

Generate a gRPC request from proto files

In the proto file, click Generate request in HTTP Client near the RPC method.

Generate a gRPC request from Endpoints tool window

Just like for HTTP requests, you can also use the Endpoints tool window to generate gRPC requests.

Open the Endpoints tool window: View | Tool Windows | Endpoints. You will see gRPC endpoints if they are defined in your project.
Select an endpoint. This will generate a sample request to it in the HTTP Client tab.
Complete the request and click Submit Request. You may need to substitute the default address and port with your own values. For the request body, use code completion based on the data structure in the proto file.
Preview the response in the lower part of the the HTTP Client tab.

Send gRPC metadata

Below your GRPC request, enter gRPC metadata using the following syntax: Metadata-key: Value.
For example:
GRPC localhost:8080 X-Myhostname: Example.org

Use secure gRPC

You can initiate connections secured by server-side TLS.

Before the address, enter grpcs, for example:
GRPC grpcs://ijhttp-examples.jetbrains.com/hello.HelloService/SayHello

WebSocket requests

The HTTP Client supports WebSocket requests. For the HTTP Client to treat your request as a WebSocket request, start it with the WEBSOCKET keyword followed by a server address. The request has the following structure:

            WEBSOCKET ws://localhost:8080/websocket
            Content-Type: application-json // Used for content highlighting only

            // Request body, for example:
            {
              "message": "First message sent on connection"
            }
            ===  // message separator
            {
              "message": "Second message" // will be sent right after the previous one
            }
            === wait-for-server  // keyword used to wait for the server response
            {
              "message": "Send this after the server response"
            }
        

To speed up composing a WebSocket request, you can:

Click on top of the editor panel of an .http file and select WebSocket Request.
In an .http file, type wsr and press Enter to apply the WebSocket live template.

Send multiple messages

Use the === separator to send multiple messages:
{ "message": "First message sent on connection" } === // message separator { "message": "Second message" } === { "message": "Third message" }

Send messages after the server response

Before a message, enter === wait-for-server.
This will make the HTTP Client wait for the server response before sending the message. You can wait for multiple responses by repeating the === wait-for-server line. For example, the following message will be sent after 3 server responses:
=== wait-for-server === wait-for-server === wait-for-server { "message": "This messages is sent after 3 server responses" }

Send messages interactively

Once you have initiated a connection, you can interact with your server right from the Services tool window. You can send messages and view server responses to each new message.

In the Services tool window, select an opened connection.
In the lower part of the window, under Message to be sent to WebSocket, enter the message content.
To the right of it, select the message format: plain text, JSON, XML, or HTML.
Press Ctrl+Enter to send the request.

In the upper part of the window, you'll see the server response.

GraphQL

IntelliJ IDEA provides support for sending GraphQL operations in the HTTP request body. You can send them over HTTP or WebSocket.

Compose an HTTP request with GraphQL query

In an .http file, enter the GRAPHQL keyword followed by a server address.
In the request body, compose your GraphQL operation (query, mutation, or subscription), for example:
### HTTP request with GraphQL query GRAPHQL http://localhost:8080/graphql query { toDos { title, completed, author { username } } }

To speed up composing an HTTP request with a GraphQL query, you can:

Click on top of the editor panel of an .http file and select GraphQL Query Request.
In an .http file, type gqlr and press Enter to apply the GraphQL live template.

Use GraphQL variables

In the HTTP request body, you can use GraphQL variables if you want to pass some dynamic data separately from the query string.

After the query part, enter a JSON variables dictionary:
query ($name: String!, $capital: String!) { country(name: $name, capital: $capital) { name capital } } { "name": "France", "capital": "Paris" }
You can also use HTTP Client environment variables as GraphQL variable values. For example, in this JSON, "{{Author}}" is an environment variable; its value at runtime depends on the environment that you select while sending the request:
{ "author": "{{Author}}" }

Create GraphQL request from Spring controller

If you use GraphQL in your Spring applications, you can quickly create HTTP requests from your controller source code using the dedicated gutter icon.

In your Spring controller code, click in the gutter next to the @QueryMapping, @MutationMapping, or @SubscriptionMapping annotation.
In the context menu that opens, select Generate request in HTTP Client.

Generating HTTP request from Spring GraphqL

This will add a new GRAPHQL request to the generated-requests.http file.

Configure proxy settings

In the Settings dialog (Ctrl+Alt+S) , choose System Settings under Appearance & Behavior, then choose HTTP Proxy.
In the HTTP Proxy dialog that opens, select Manual proxy configuration and specify the following:
- Enter the proxy host name and port number in the Host name and Port number fields.
- To enable authorization, select the Proxy authentication checkbox and type the username and password in the corresponding fields.

Set up client SSL/TLS certificate

If an HTTP server requires SSL/TLS authentication for secure communication, you may need to specify the client certificate before sending an HTTPS request. In the HTTP Client, you can set up the client certificate using the private environment file.

Specify path to certificate

In an .http file, in the Run with list, select Add Environment to Private File.
In the http-client.private.env.json file that opens, add the SSLConfiguration object to the needed environment. In clientCertificate, enter a path to your client certificate. If a certificate key is stored in a separate file, enter its path in clientCertificateKey. For example:
{ "dev": { "MyVar": "SomeValue", "SSLConfiguration": { "clientCertificate": "cert.pem", "clientCertificateKey": "MyFolder/key.pem" } } }
You can specify an absolute path or a path relative to the http-client.private.env.json file. If the environment file is stored in scratches, you can additionally specify a path relative to your project root. Start typing a path to get the code completion popup.
Alternatively, you can describe clientCertificate and clientCertificateKey as objects, which lets you specify the certificate format in addition to the path. For example:
{ "dev": { "SSLConfiguration": { "clientCertificate": { "path": "file.crt", "format": "PEM" }, "clientCertificateKey": { "path": "file.key", "format": "DER" } } } }

Set up a certificate passphrase

If you used a passphrase when generating your client certificate, you should provide it to the HTTP Client.

In the http-client.private.env.json file, add "hasCertificatePassphrase": true to the SSLConfiguration object, for example:
{ "dev": { "SSLConfiguration": { "clientCertificate": "file.crt", "hasCertificatePassphrase": true } } }
Click in the gutter or, with the caret placed at hasCertificatePassphrase, press Alt+Enter and select Set value for 'Certificate passphrase'.
In the window that opens, enter your certificate passphrase.

You can omit the second step if you do not want to enter the passphrase now. In this case, IntelliJ IDEA will prompt you to enter the passphrase when you execute an HTTPS request.

Disable certificate verification

For development purposes, you may have a host with self-signed or expired certificates. If you trust this host, you can disable verification of its certificate.

In the http-client.private.env.json file, add verifyHostCertificate": false to the SSLConfiguration object. For example:
{ "sslTest": { "SSLConfiguration": { "verifyHostCertificate": false } } }

If you run a request with this environment, IntelliJ IDEA will not verify host certificates.