Chrome DevTools Protocol

Methods

Fetch.continueRequest

Continues the request, optionally modifying some of its parameters.

parameters
requestId
RequestId

An id the client received in requestPaused event.

url
string

If set, the request url will be modified in a way that's not observable by page.

method
string

If set, the request method is overridden.

postData
string

If set, overrides the post data in the request. (Encoded as a base64 string when passed over JSON)

headers
array[ HeaderEntry ]

If set, overrides the request headers. Note that the overrides do not extend to subsequent redirect hops, if a redirect happens. Another override may be applied to a different request produced by a redirect.

interceptResponse
boolean

If set, overrides response interception behavior for this request.

Experimental

Fetch.continueWithAuth

Continues a request supplying authChallengeResponse following authRequired event.

parameters
requestId
RequestId

An id the client received in authRequired event.

authChallengeResponse
AuthChallengeResponse

Response to with an authChallenge.

Fetch.disable

Disables the fetch domain.

Fetch.enable

Enables issuing of requestPaused events. A request will be paused until client calls one of failRequest, fulfillRequest or continueRequest/continueWithAuth.

parameters
patterns
array[ RequestPattern ]

If specified, only requests matching any of these patterns will produce fetchRequested event and will be paused until clients response. If not set, all requests will be affected.

handleAuthRequests
boolean

If true, authRequired events will be issued and requests will be paused expecting a call to continueWithAuth.

Fetch.failRequest

Causes the request to fail with specified reason.

parameters
requestId
RequestId

An id the client received in requestPaused event.

errorReason
Network.ErrorReason

Causes the request to fail with the given reason.

Fetch.fulfillRequest

Provides response to the request.

parameters
requestId
RequestId

An id the client received in requestPaused event.

responseCode
integer

An HTTP response code.

responseHeaders
array[ HeaderEntry ]

Response headers.

binaryResponseHeaders
string

Alternative way of specifying response headers as a \0-separated series of name: value pairs. Prefer the above method unless you need to represent some non-UTF8 values that can't be transmitted over the protocol as text. (Encoded as a base64 string when passed over JSON)

body
string

A response body. If absent, original response body will be used if the request is intercepted at the response stage and empty body will be used if the request is intercepted at the request stage. (Encoded as a base64 string when passed over JSON)

responsePhrase
string

A textual representation of responseCode. If absent, a standard phrase matching responseCode is used.

Fetch.getResponseBody

Causes the body of the response to be received from the server and returned as a single string. May only be issued for a request that is paused in the Response stage and is mutually exclusive with takeResponseBodyForInterceptionAsStream. Calling other methods that affect the request or disabling fetch domain before body is received results in an undefined behavior. Note that the response body is not available for redirects. Requests paused in the redirect received state may be differentiated by responseCode and presence of location response header, see comments to requestPaused for details.

parameters
requestId
RequestId

Identifier for the intercepted request to get body for.

Return Object
body
string

Response body.

base64Encoded
boolean

True, if content was sent as base64.

Fetch.takeResponseBodyAsStream

Returns a handle to the stream representing the response body. The request must be paused in the HeadersReceived stage. Note that after this command the request can't be continued as is -- client either needs to cancel it or to provide the response body. The stream only supports sequential read, IO.read will fail if the position is specified. This method is mutually exclusive with getResponseBody. Calling other methods that affect the request or disabling fetch domain before body is received results in an undefined behavior.

parameters
requestId
RequestId
Return Object
stream
IO.StreamHandle

Fetch.continueResponse Experimental

Continues loading of the paused response, optionally modifying the response headers. If either responseCode or headers are modified, all of them must be present.

parameters
requestId
RequestId

An id the client received in requestPaused event.

responseCode
integer

An HTTP response code. If absent, original response code will be used.

responsePhrase
string

A textual representation of responseCode. If absent, a standard phrase matching responseCode is used.

responseHeaders
array[ HeaderEntry ]

Response headers. If absent, original response headers will be used.

binaryResponseHeaders
string

Alternative way of specifying response headers as a \0-separated series of name: value pairs. Prefer the above method unless you need to represent some non-UTF8 values that can't be transmitted over the protocol as text. (Encoded as a base64 string when passed over JSON)

Events

Fetch.authRequired

Issued when the domain is enabled with handleAuthRequests set to true. The request is paused until client responds with continueWithAuth.

parameters
requestId
RequestId

Each request the page makes will have a unique id.

request
Network.Request

The details of the request.

frameId
Page.FrameId

The id of the frame that initiated the request.

resourceType
Network.ResourceType

How the requested resource will be used.

authChallenge
AuthChallenge

Details of the Authorization Challenge encountered. If this is set, client should respond with continueRequest that contains AuthChallengeResponse.

Fetch.requestPaused

Issued when the domain is enabled and the request URL matches the specified filter. The request is paused until the client responds with one of continueRequest, failRequest or fulfillRequest. The stage of the request can be determined by presence of responseErrorReason and responseStatusCode -- the request is at the response stage if either of these fields is present and in the request stage otherwise. Redirect responses and subsequent requests are reported similarly to regular responses and requests. Redirect responses may be distinguished by the value of responseStatusCode (which is one of 301, 302, 303, 307, 308) along with presence of the location header. Requests resulting from a redirect will have redirectedRequestId field set.

parameters
requestId
RequestId

Each request the page makes will have a unique id.

request
Network.Request

The details of the request.

frameId
Page.FrameId

The id of the frame that initiated the request.

resourceType
Network.ResourceType

How the requested resource will be used.

responseErrorReason
Network.ErrorReason

Response error if intercepted at response stage.

responseStatusCode
integer

Response code if intercepted at response stage.

responseStatusText
string

Response status text if intercepted at response stage.

responseHeaders
array[ HeaderEntry ]

Response headers if intercepted at the response stage.

networkId
Network.RequestId

If the intercepted request had a corresponding Network.requestWillBeSent event fired for it, then this networkId will be the same as the requestId present in the requestWillBeSent event.

redirectedRequestId
RequestId

If the request is due to a redirect response from the server, the id of the request that has caused the redirect.

Experimental

Types

Fetch.AuthChallenge

Authorization challenge for HTTP status code 401 or 407.

Type: object

properties
source
string

Source of the authentication challenge.

Allowed Values: Server, Proxy
origin
string

Origin of the challenger.

scheme
string

The authentication scheme used, such as basic or digest

realm
string

The realm of the challenge. May be empty.

Fetch.AuthChallengeResponse

Response to an AuthChallenge.

Type: object

properties
response
string

The decision on what to do in response to the authorization challenge. Default means deferring to the default behavior of the net stack, which will likely either the Cancel authentication or display a popup dialog box.

Allowed Values: Default, CancelAuth, ProvideCredentials
username
string

The username to provide, possibly empty. Should only be set if response is ProvideCredentials.

password
string

The password to provide, possibly empty. Should only be set if response is ProvideCredentials.

Fetch.HeaderEntry

Response HTTP header entry

Type: object

properties
name
string
value
string

Fetch.RequestId

Unique request identifier. Note that this does not identify individual HTTP requests that are part of a network request.

Type: string

Fetch.RequestPattern

Type: object

properties
urlPattern
string

Wildcards ('*' -> zero or more, '?' -> exactly one) are allowed. Escape character is backslash. Omitting is equivalent to "*".

resourceType
Network.ResourceType

If set, only requests for matching resource types will be intercepted.

requestStage
RequestStage

Stage at which to begin intercepting requests. Default is Request.

Fetch.RequestStage

Stages of the request to handle. Request will intercept before the request is sent. Response will intercept after the response is received (but before response body is received).

Allowed Values: Request, Response

Type: string