I am clicking a button on a web page that calls an API and generated the response below. Is there a way to get the response value programmatically without having UiPath open the console?
I know there is a way to call the API, but the website is not mine, so I am unsure what variables to pass.
Since the API response is visible in the browser, it means the browser already has the JSON in memory.
You can use Java script to extract it, use the script in UiPath using inject JS acrivity
Thanks for the reply.
Any pointers on where to begin with this script? I am not too familiar with JavaScript. Is there a specific function you are referring to?
Are you using any specific url and also which browser you are using this?
Give me basic details, ill test for function
An example link is Steffes Group | Richard Schlichtmann Estate Farm Auction Lot Listings
Iâm clicking the number of bids in the item listing to call the API and generate the JSON response.
Use this in JS activirty.
"(function() {
var open = XMLHttpRequest.prototype.open;
var send = XMLHttpRequest.prototype.send;
XMLHttpRequest.prototype.open = function(method, url) {
this._url = url;
open.apply(this, arguments);
};
XMLHttpRequest.prototype.send = function(body) {
this.addEventListener('load', function() {
if (this._url.includes('track')) {
window.lastApiResponse = this.responseText;
}
});
send.apply(this, arguments);
};
})();"
Iâll give that code a try if I have time today. Thanks a bunch!
I created a sample local HTML file (LocalHTMLPage.html) that performs a RestAPI call in the backend when you press the Search Users button.
It uses two Inject Js Script activities:
Inject Js Script - Verify if you can detect ANY network activity
Inject Js Script - Get the API data
Before the Inject Js Script - Get the API data perform the UI element action that will trigger the Rest API call. Use delays between actions so it will get a successful loaded Rest API call with results.
Use the attached Studio 2025.10.1 project as reference.
InterceptRestAPIWithInjectJsScriptActivity.zip (1.8 MB)
Created and tested under Studio 2025.10.1
Windows project compatibility with VB.Net language
This UiPath Studio project is an API monitoring and data extraction automation that performs the following tasks:
Main Purpose
The project monitors and captures REST API calls made by a web application, then extracts and logs the API response data for analysis.
Workflow Breakdown
1. Application Setup
Opens a local HTML file (LocalHTMLPage.html) containing a âUser Management Systemâ
Uses Microsoft Edge browser
Maximizes the browser window
2. JavaScript Injection for API Monitoring
Injects a script that intercepts all network requests:
Monitors XMLHttpRequest (traditional AJAX calls)
Monitors Fetch API (modern JavaScript requests)
Captures detailed information for each API call:
Request type (XHR/Fetch)
URL
HTTP method
Status code
Response headers
Response body
Timestamp
3. User Interaction
Clicks the âSearch Usersâ button on the web page
This triggers the actual REST API calls that will be intercepted
4. Data Extraction & Processing
Retrieves captured API data using another JavaScript injection
Parses JSON responses using Newtonsoft.Json
Extracts specific API details:
type (request type)
url (API endpoint)
method (HTTP method)
status (HTTP status code)
responseBody (actual API response data)
timestamp (when the call was made)
5. Logging & Output
Logs all extracted API information to the UiPath output panel
Provides detailed trace of the API monitoring results
Technical Components
Variables Used:
out_GetAPIData_JSON - Raw JSON array from JavaScript
jArray, firstItem - For JSON parsing
out_type, out_url, out_method, etc. - Extracted API properties
Key Activities:
NInjectJsScript - JavaScript injection for monitoring
NClick - UI interaction
DeserializeJson - JSON parsing
MultipleAssign - Extracting multiple properties
LogMessage - Output results
What It Achieves
Real-time API Monitoring: Captures all REST API calls made by the web application
Data Extraction: Pulls out specific API details (URLs, methods, responses)
Structured Output: Formats the data for easy analysis
Testing Tool: Useful for QA testing, API debugging, and monitoring web application behavior
Use Cases
API Testing: Verify that web applications make correct API calls
Performance Monitoring: Track API response times and success rates
Debugging: Identify issues with API endpoints or data formats
Data Extraction: Capture API responses for further processing
Security Testing: Monitor what data is being sent/received
Expected Output
When you run this automation, youâll see logs showing:
The API endpoints called (like https://jsonplaceholder.typicode.com/users)
HTTP methods used (GET, POST, etc.)
Status codes (200, 404, etc.)
The actual JSON response data from the APIs
Timestamps of when calls were made
This is essentially a web API monitoring robot that helps you understand and analyze the backend communication of web applications!
Have you tried Application Event Trigger? With a <html /> selector, you can monitor web requests Activities - Application Event Trigger
I likely have something wrong, but I am getting an error when running this activity - Inject Js Script: TypeError: n is not a function
I donât see anything wrong with your code, so I assume it is something Iâve done incorrectly.
Set input parameter to New List(Of Object).
Got it since our script does not require any input, so letâs set: Input Parameter = ââ
I changed input parameter to ââ. Same error has before - n is not a function.
When you writing script , donât enclose in ââ. Give only code.
Try the steps exactly as follows: Use an empty string "" as the Input parameter, and set Execution World = Page so the script runs in the actual page context. Then inject the following JS without quotes to intercept the API call:
(function () {
const open = XMLHttpRequest.prototype.open;
const send = XMLHttpRequest.prototype.send;
XMLHttpRequest.prototype.open = function (method, url) {
this._url = url;
open.apply(this, arguments);
};
XMLHttpRequest.prototype.send = function (body) {
this.addEventListener('load', function () {
if (this._url.includes('YOUR_API_KEYWORD')) {
window.lastApiResponse = this.responseText;
}
});
send.apply(this, arguments);
};
})();
After triggering the action that makes the API call, run a second Inject JS Script (again with Input = "") containing:
return window.lastApiResponse;
This returns the captured API response to UiPath.
the same data might be coming on ui as well right..any specific reason why you want to extract from console only?
cheers
@Dan_Munteanu
From my tries, the Application Event Trigger for click doesnât work for default selector and UI default framework, as it expects an app selector from Active Accessibility.
Invalid Trigger. Only 'app' attribute is allowed for 'html' selector. Exception Type: UiPath.UIAutomationNext.Exceptions.UiAutomationException in .local\generated\Triggers.Generated.xaml at NNativeEventTrigger`1 "Application Event Trigger 'Search Users'" at TriggerScope "TriggerScope" at Sequence "Sequence" at Sequence "Sequence" at Triggers_Generated "Triggers.Generated" UiPath.UIAutomationNext.Exceptions.UiAutomationException: Invalid Trigger. Only 'app' attribute is allowed for 'html' selector. ---> System.Runtime.InteropServices.COMException: Exception from HRESULT: 0x80040329 at UiPath.UiNodeMonitorClass.MonitorNativeEvent(String bstrSelector, String nativeEvent, Boolean isCollapsable, Boolean matchSync, Boolean matchChildren, Boolean searchInvisibleChildren, String bstrServerUrlForBrowserEvents) at UiPath.UIAutomationNext.Triggers.EventMonitor.<>c__DisplayClass23_0.<RegisterNativeEventInternal>b__0() at UiPath.UIAutomationNext.Services.DriverServiceCore.WrapCom[T](Func`1 toExecute) --- End of inner exception stack trace --- at UiPath.UIAutomationNext.Extensions.ExceptionExtensions.GetFriendly(COMException comException) at UiPath.UIAutomationNext.Extensions.ExceptionExtensions.ThrowFriendly(COMException comException) at UiPath.UIAutomationNext.Services.DriverServiceCore.WrapCom[T](Func`1 toExecute) at UiPath.UIAutomationNext.Triggers.EventMonitor.RegisterNativeEventInternal(SelectorTriggerNativeEventData triggerData, Boolean saveMonitorId) at UiPath.UIAutomationNext.Triggers.EventMonitor.<RegisterNativeEvent>b__19_0(SelectorTriggerNativeEventData t) at System.Linq.Utilities.<>c__DisplayClass2_0`3.<CombineSelectors>b__0(TSource x) at System.Linq.Enumerable.SelectEnumerableIterator`2.ToList() at UiPath.UIAutomationNext.Triggers.EventMonitor.RegisterNativeEvent(IEnumerable`1 triggerData) at UiPath.UIAutomationNext.Services.EventMonitorFactory.Create(IEnumerable`1 triggerData) at UiPath.UIAutomationNext.Activities.NNativeEventTrigger`1.CreateMonitor(NativeActivityContext context, IEventMonitorFactory factory, IRuntimeContext runtimeContext, Action`1 sendTrigger) at UiPath.UIAutomationNext.Activities.TriggerBase`1.StartMonitor(NativeActivityContext context, Action`1 sendTrigger) at UiPath.Platform.Triggers.TriggerBase`1.Execute(NativeActivityContext context) at UiPath.Platform.Triggers.InterruptibleTriggerBase`1.ExecuteAsInterruptibleTrigger(NativeActivityContext context) at UiPath.Platform.Triggers.InterruptibleTriggerBase`1.Execute(NativeActivityContext context) at System.Activities.NativeActivity.InternalExecute(ActivityInstance instance, ActivityExecutor executor, BookmarkManager bookmarkManager) at System.Activities.Runtime.ActivityExecutor.ExecuteActivityWorkItem.ExecuteBody(ActivityExecutor executor, BookmarkManager bookmarkManager, Location resultLocation)
Can you provide an updated version of the ApplicationEventTriggerSequence.xaml that works as expected for the provided sample?
InterceptRestAPIWithInjectJsScriptActivity.zip (6.1 MB)
@marian.platonov Thanks for trying it.
This exception is expected: âInvalid Trigger. Only âappâ attribute is allowed for âhtmlâ selector.â It canât be the default one because for most tab (html) level events, we have to monitor all tabs, and details about the tab that triggered the event should be visible in the TriggerEventArgs.
In your case, use a simple selector <html app='chrome.exe' />
I attached a workflow that works with UiAutomation 24.10.14.
Each trigger is in its own workflow and the main.xaml calls âRun Local Triggersâ activity to start them all.
I first tried using 25.10.22, but I couldnât get past UI issues that Iâm going to share with the team.