Implementation:Cypress io Cypress OpenModule Start

Knowledge Sources	Cypress Cypress CLI
Domains	CLI, Process_Management
Last Updated	2026-02-12 00:00 GMT

Overview

Concrete tool for launching the Cypress interactive test runner provided by the CLI open module.

Description

The openModule.start function processes CLI options and spawns the Cypress binary as a child process in interactive (open) mode. It first verifies the binary installation, then maps user options to server arguments via processOpenOptions, and finally invokes spawn.start to launch the Electron application.

Usage

This function is called when a user runs cypress open from the command line or invokes it programmatically via the Cypress module API.

Code Reference

Source Location

• Repository: cypress-io/cypress
• File: cli/lib/exec/open.ts
• Lines: L81-106

Signature

const start = async (options: any = {}): Promise<any> => {
  // options.dev: boolean - run in development mode
  // options.detached: boolean - detach the spawned process
  // options.project: string - project directory path
  // options.browser: string - preferred browser
  // options.testingType: string - 'e2e' or 'component'
  // options.config: string - inline config overrides
  // Calls processOpenOptions(options) to map to server args
  // Calls spawn.start(args, { dev, detached }) to launch binary
}

Import

import openModule from '../exec/open'
// Usage: await openModule.start(options)

I/O Contract

Inputs

Name	Type	Required	Description
options	object	No	Open command options
options.project	string	No	Project directory path
options.browser	string	No	Browser name or path
options.testingType	string	No	'e2e' or 'component'
options.config	string	No	Inline config overrides
options.dev	boolean	No	Development mode flag
options.detached	boolean	No	Detach spawned process

Outputs

Name	Type	Description
Child process	Promise<any>	Resolves when the Cypress Electron app is launched
Interactive UI	Electron window	Launchpad UI for project setup and test selection

Usage Examples

CLI Usage

# Open interactive mode
npx cypress open

# Open with specific project
npx cypress open --project ./my-app

# Open with specific browser
npx cypress open --browser chrome

# Open in component testing mode
npx cypress open --component

Programmatic Usage

const cypress = require('cypress')

cypress.open({
  project: './my-app',
  browser: 'chrome',
  testingType: 'e2e',
})

Related Pages

Implements Principle

• Principle:Cypress_io_Cypress_Test_Runner_Launch

Requires Environment

• Environment:Cypress_io_Cypress_Browser_Requirements
• Environment:Cypress_io_Cypress_Linux_Display_Server

Uses Heuristic

• Heuristic:Cypress_io_Cypress_Xvfb_Display_Gotcha