Remote Protocol

The Firefox Remote Protocol is a low-level debugging interface based on the CDP protocol. With it, you can inspect the state and control execution of documents running in web content, instrument Gecko in interesting ways, simulate user interaction for automation purposes, and debug JavaScript execution

Select a component to see open bugs in that component:


Underlying transport layer and server to allow remoting of Firefox for automation and debugging.


The core implementation for CDP support. Please file domain specific issues and requests under the appropriate CDP-prefixed Remote Protocol component.

CDP: Browser

Application and process management, permissions management.

CDP: Debugger

Debugger domain exposes JavaScript debugging capabilities. It allows setting and removing breakpoints, stepping through execution, exploring stack traces, &c.


Exposes DOM read/write operations

CDP: Emulation

Emulation of different environments, throttling, document scaling factors, and various overrides.

CDP: Fetch

A domain for letting clients substitute browser's network layer with client code.

CDP: Input

User interaction emulation

CDP: Inspector

Experimental CDP Inspector domain


Input/output operations for streams produced by the debugger

CDP: Log

Methods for extracting different log types like console, network, or performance logs.

CDP: Network

Tracking page network activities, information about HTTP, file, data and other requests and responses, their headers, bodies, timing, &c.

CDP: Page

Methods for interacting with a page or tab.

CDP: Performance

Metrics collection.

CDP: Runtime

Methods for executing JavaScript on a page.

CDP: Security

Tracking of security state changes and enables security overrides to be installed.

CDP: Target

Target discovery and attachment, incoming command request multiplexing and despatching.

WebDriver BiDi

W3C WebDriver BiDi implementation for Gecko-based browsers.