Web Request

The Web Request command (Command Type: 18) hooks into the browser’s web request lifecycle and intercepts HTTP requests at specified stages (before sending headers, on response, on error, etc.).

Command Type

Command Type ID: 18

Parameters

Parameter	Type	Description	Required
listener	string	Web request lifecycle event to listen for	Yes
name	string	Unique identifier for this listener	Yes
timeout	number	Timeout in milliseconds	Yes
filters	WebRequest.RequestFilter	Criteria to filter which requests trigger the listener	No
options	WebRequestOptions	Additional options for request handling	No

Listener Values

Value	Description
`"onBeforeRequest"`	Triggered before a request is made
`"onBeforeSendHeaders"`	Triggered before headers are sent
`"onSendHeaders"`	Triggered after headers are sent
`"onHeadersReceived"`	Triggered after headers are received
`"onAuthRequired"`	Triggered when server requires authentication
`"onBeforeRedirect"`	Triggered before a redirect
`"onCompleted"`	Triggered when request completes successfully
`"onErrorOccurred"`	Triggered when an error occurs
`"onResponseStarted"`	Triggered when the response body starts arriving

WebRequest.RequestFilter

Field	Type	Description	Required
urls	Array of string	URL patterns to match	Yes
types	Array of string	Resource types to match	No
tabId	number	Match specific tab	No
incognito	boolean	Match incognito state	No

Usage Examples

Capture API Responses

{
  "command": "web-request",
  "params": {
    "listener": "onCompleted",
    "name": "apiListener",
    "timeout": 30000,
    "filters": {
      "urls": ["*://api.example.com/*"],
      "types": ["xmlhttprequest"]
    }
  }
}

Intercept Before Headers Are Sent

{
  "command": "web-request",
  "params": {
    "listener": "onBeforeSendHeaders",
    "name": "headerInterceptor",
    "timeout": 15000,
    "filters": { "urls": ["*://example.com/*"] }
  }
}

Override Headers - Override request headers
Fetch Web Request - Make fetch requests
Capture HAR File - Capture all network activity

Quick Start

Commands Glossary

Command Type

Parameters

Listener Values

WebRequest.RequestFilter

Usage Examples

Capture API Responses

Intercept Before Headers Are Sent

​Command Type

​Parameters

​Listener Values

​WebRequest.RequestFilter

​Usage Examples

​Capture API Responses

​Intercept Before Headers Are Sent

​Related Commands

Command Type

Parameters

Listener Values

WebRequest.RequestFilter

Usage Examples

Capture API Responses

Intercept Before Headers Are Sent

Related Commands