chrome.debugger

Description

The chrome.debugger API serves as an alternate transport for Chrome's remote debugging protocol. Use chrome.debugger to attach to one or more tabs to instrument network interaction, debug JavaScript, mutate the DOM and CSS, and more. Use the Debuggee property tabId to target tabs with sendCommand and route events by tabId from onEvent callbacks.

Permissions

debugger

Security Note

For security reasons, the chrome.debugger API does not provide access to all Chrome DevTools Protocol Domains. The available domains are: Accessibility, Audits, CacheStorage, Console, CSS, Database, Debugger, DOM, DOMDebugger, DOMSnapshot, Emulation, Fetch, IO, Input, Inspector, Log, Network, Overlay, Page, Performance, Profiler, Runtime, Storage, Target, Tracing, WebAudio, and WebAuthn.

Manifest

You must declare the "debugger"` permission in your extension's manifest to use this API.

{
  "name": "My extension",
  ...
  "permissions": [
    "debugger",
  ],
  ...
}

Examples

To try this API, install the debugger API example from the chrome-extension-samples repository.

Types

Debuggee

Debuggee identifier. Either tabId, extensionId or targetId must be specified

Properties

  • extensionId

    string optional

    The id of the extension which you intend to debug. Attaching to an extension background page is only possible when the --silent-debugger-extension-api command-line switch is used.

  • tabId

    number optional

    The id of the tab which you intend to debug.

  • targetId

    string optional

    The opaque id of the debug target.

DebuggerSession

Chrome 125+

Debugger session identifier. One of tabId, extensionId or targetId must be specified. Additionally, an optional sessionId can be provided. If sessionId is specified for arguments sent from onEvent, it means the event is coming from a child protocol session within the root debuggee session. If sessionId is specified when passed to sendCommand, it targets a child protocol session within the root debuggee session.

Properties

  • extensionId

    string optional

    The id of the extension which you intend to debug. Attaching to an extension background page is only possible when the --silent-debugger-extension-api command-line switch is used.

  • sessionId

    string optional

    The opaque id of the Chrome DevTools Protocol session. Identifies a child session within the root session identified by tabId, extensionId or targetId.

  • tabId

    number optional

    The id of the tab which you intend to debug.

  • targetId

    string optional

    The opaque id of the debug target.

DetachReason

Chrome 44+

Connection termination reason.

Enum

"target_closed"

"canceled_by_user"

TargetInfo

Debug target information

Properties

  • attached

    boolean

    True if debugger is already attached.

  • extensionId

    string optional

    The extension id, defined if type = 'background_page'.

  • faviconUrl

    string optional

    Target favicon URL.

  • id

    string

    Target id.

  • tabId

    number optional

    The tab id, defined if type == 'page'.

  • title

    string

    Target page title.

  • Target type.

  • url

    string

    Target URL.

TargetInfoType

Chrome 44+

Target type.

Enum

"page"

"background_page"

"worker"

"other"

Methods

attach()

Promise 
chrome.debugger.attach(
  target: Debuggee,
  requiredVersion: string,
  callback?: function,
)

Attaches debugger to the given target.

Parameters

  • target

    Debuggee

    Debugging target to which you want to attach.

  • requiredVersion

    string

    Required debugging protocol version ("0.1"). One can only attach to the debuggee with matching major version and greater or equal minor version. List of the protocol versions can be obtained here.

  • callback

    function optional

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 96+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

detach()

Promise 
chrome.debugger.detach(
  target: Debuggee,
  callback?: function,
)

Detaches debugger from the given target.

Parameters

  • target

    Debuggee

    Debugging target from which you want to detach.

  • callback

    function optional

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 96+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

getTargets()

Promise 
chrome.debugger.getTargets(
  callback?: function,
)

Returns the list of available debug targets.

Parameters

  • callback

    function optional

    The callback parameter looks like: 

    (result: TargetInfo[]) => void

    • result

      TargetInfo[]

      Array of TargetInfo objects corresponding to the available debug targets.

Returns

  • Promise<TargetInfo[]>

    Chrome 96+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

sendCommand()

Promise 
chrome.debugger.sendCommand(
  target: DebuggerSession,
  method: string,
  commandParams?: object,
  callback?: function,
)

Sends given command to the debugging target.

Parameters

  • Debugging target to which you want to send the command.

  • method

    string

    Method name. Should be one of the methods defined by the remote debugging protocol.

  • commandParams

    object optional

    JSON object with request parameters. This object must conform to the remote debugging params scheme for given method.

  • callback

    function optional

    The callback parameter looks like: 

    (result?: object) => void

    • result

      object optional

      JSON object with the response. Structure of the response varies depending on the method name and is defined by the 'returns' attribute of the command description in the remote debugging protocol.

Returns

  • Promise<object | undefined>

    Chrome 96+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

Events

onDetach

chrome.debugger.onDetach.addListener(
  callback: function,
)

Fired when browser terminates debugging session for the tab. This happens when either the tab is being closed or Chrome DevTools is being invoked for the attached tab.

Parameters

onEvent

chrome.debugger.onEvent.addListener(
  callback: function,
)

Fired whenever debugging target issues instrumentation event.

Parameters

  • callback

    function

    The callback parameter looks like: 

    (source: DebuggerSession, method: string, params?: object) => void