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paramName
( optional enumerated Type array of paramType )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
Parameters

Google Chrome Extensions (Labs)

WebRequest API

WebRequest API

Use the chrome.experimental.webRequest module to intercept, block, or modify requests in-flight. This module is still very much experimental. For information on how to use experimental APIs, see the chrome.experimental.* APIs page.

A note about timestamps

It's important to note that some technical oddities in the OS's handling of distinct Chrome processes can cause the clock to be skewed between the browser itself and extension processes. That means that WebRequest's events' timeStamp property is only guaranteed to be internally consistent. Comparing one event to another event will give you the correct offset between them, but comparing them to the current time inside the extension (via (new Date()).getTime(), for instance) might give unexpected results.

API reference: chrome.experimental.webRequest

Methods

Events

onBeforeRedirect

chrome.experimental.webRequest.onBeforeRedirect.addListener(function(object details) {...});

Fires when a server initiated redirect is about to occur.

Parameters

details
( Type array of object )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
requestId
( Type array of string )
The ID of the request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
url
( Type array of string )
The URL of the current request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
statusCode
( Type array of integer )
Standard HTTP status code returned by the server.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
redirectUrl
( Type array of string )
The new URL.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
timeStamp
( Type array of number )
The time when the browser was about to make the redirect, in milliseconds since the epoch.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.

onBeforeRequest

chrome.experimental.webRequest.onBeforeRequest.addListener(function(object details) {...});

Fires when a request is about to occur.

Parameters

details
( Type array of object )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
requestId
( Type array of string )
The ID of the request. Request IDs are unique within a browser session. As a result, they could be used to relate different events of the same request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
url
( Type array of string )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
method
( Type array of string )
Standard HTTP method.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
tabId
( Type array of integer )
The ID of the tab in which the request takes place. Set to null if the request isn't related to a tab.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
type
( enumerated Type array of string ["main_frame", "sub_frame", "stylesheet", "script", "image", "object", "other"] )
How the requested resource will be used.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
timeStamp
( Type array of number )
The time when the browser was about to make the request, in milliseconds since the epoch.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.

onBeforeSendHeaders

chrome.experimental.webRequest.onBeforeSendHeaders.addListener(function(object details) {...});

Fires before sending an HTTP request, once the request headers are available.

Parameters

details
( Type array of object )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
requestId
( Type array of string )
The ID of the request. Request IDs are unique within a browser session. As a result, they could be used to relate different events of the same request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
url
( Type array of string )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
timeStamp
( Type array of number )
The time when the browser was about to send headers, in milliseconds since the epoch.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.

onCompleted

chrome.experimental.webRequest.onCompleted.addListener(function(object details) {...});

Fires when a request is completed.

Parameters

details
( Type array of object )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
requestId
( Type array of string )
The ID of the request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
url
( Type array of string )
The URL of the current request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
statusCode
( Type array of integer )
Standard HTTP status code returned by the server.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
timeStamp
( Type array of number )
The time when the response was received completely, in milliseconds since the epoch.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.

onErrorOccurred

chrome.experimental.webRequest.onErrorOccurred.addListener(function(object details) {...});

Fires when an error occurs.

Parameters

details
( Type array of object )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
requestId
( Type array of string )
The ID of the request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
url
( Type array of string )
The URL of the current request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
error
( Type array of string )
The error description.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
timeStamp
( Type array of number )
The time when the error occurred, in milliseconds since the epoch.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.

onHeadersReceived

chrome.experimental.webRequest.onHeadersReceived.addListener(function(object details) {...});

Fires when the status line and response headers are received after a request is sent to the server.

Parameters

details
( Type array of object )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
requestId
( Type array of string )
The ID of the request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
url
( Type array of string )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
statusCode
( Type array of integer )
Standard HTTP status code returned by the server.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
timeStamp
( Type array of number )
The time when the status line and response headers were received, in milliseconds since the epoch.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.

onRequestSent

chrome.experimental.webRequest.onRequestSent.addListener(function(object details) {...});

Fires when a request is sent to the server.

Parameters

details
( Type array of object )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
requestId
( Type array of string )
The ID of the request.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
url
( Type array of string )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
ip
( Type array of string )
The server IP address that is actually connected to. Note that it may be a literal IPv6 address.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
timeStamp
( Type array of number )
The time when the browser finished sending the request, in milliseconds since the epoch.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.

Types

RequestFilter

paramName
( Type array of object )
An object describing filters to apply to webRequest events.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
urls
( optional Type array of Type array of string paramType )
A list of URLs or URL patterns. Requests that cannot match any of the URLs will be filtered out.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
types
( optional Type array of Type array of string ["main_frame", "sub_frame", "stylesheet", "script", "image", "object", "other"] paramType )
A list of request types. Requests that cannot match any of the types will be filtered out.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
tabId
( optional Type array of integer )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
windowId
( optional Type array of integer )
Undocumented.
Description of this parameter from the json schema.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.

BlockingResponse

paramName
( Type array of object )
Return value for event handlers that have the 'blocking' extraInfoSpec applied. Allows the event handler to modify network requests.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
cancel
( optional Type array of boolean )
If true, the request is cancelled. Used in onBeforeRequest, this prevents the request from being sent.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.
redirectUrl
( optional Type array of string )
If set, the original request is prevented from being sent and is instead redirected to the given URL.
This parameter was added in version . You must omit this parameter in earlier versions, and you may omit it in any version. If you require this parameter, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version.