commander breaking changes

15.0.0

28 breaking changes, first published May 29, 2026.

• Removed
  Code running on older Node.js versions will no longer work with Commander 15; upgrade Node.js first. github.com
• Removed commander.esm.mjs
  Removed the deprecated commander/esm.mjs export in commander 15.0.0 github.com
• Removed esm.mjs:AddHelpTextContext
  AddHelpTextContext was removed in commander 15.0.0 npmjs.com
• Removed esm.mjs:AddHelpTextPosition
  AddHelpTextPosition was removed in commander 15.0.0 npmjs.com
• Removed esm.mjs:Argument
  Argument was removed in commander 15.0.0 npmjs.com
• Removed esm.mjs:Command
  Command was removed in commander 15.0.0 npmjs.com
• Removed esm.mjs:CommanderError
  CommanderError was removed in commander 15.0.0 npmjs.com
• Removed esm.mjs:CommandOptions
  CommandOptions was removed in commander 15.0.0 npmjs.com
• Removed esm.mjs:createArgument
  createArgument was removed in commander 15.0.0 npmjs.com
• Removed esm.mjs:createCommand
  createCommand was removed in commander 15.0.0 npmjs.com

And 18 more in this version.

14.0.0

2 breaking changes, first published May 18, 2025.

• Removed
  Commander 14 drops support for older Node.js versions. Users on Node.js versions below v20 must upgrade Node.js before upgrading Commander. github.com
• Signature changed Command.argument
  Was argument<T>(flags: string, description: string, fn: (value: string, previous: T) => T, defaultValue?: T): this; now argument<T>(flags: string, description: string, parseArg: (value: string, previous: T) => T, defaultValue?: T): this. npmjs.com

13.0.0

6 breaking changes, first published December 30, 2024.

• Removed Help.wrap
  Help.wrap() was refactored away. Use formatItem() or boxWrap() instead. npmjs.com
• Removed HelpConfiguration.wrap
  HelpConfiguration.wrap was removed in commander 13.0.0 npmjs.com
• Behavior changed Option
  Option flags such as multiple characters after a single dash now throw during Option construction. Use supported flag forms. github.com
• Behavior changed parse
  Calling parse() more than once now throws if storeOptionsAsProperties is true. Parse only once in that configuration. github.com
• Default changed allowExcessArguments
  Passing more command-arguments than declared now fails with an error. To keep the old behaviour, call allowExcessArguments() explicitly. github.com
• Signature changed Command.action
  The TypeScript parameters for the action handler callback now include the implicit this, which can affect typed handlers. npmjs.com

12.0.0

7 breaking changes, first published February 3, 2024.

• Removed
  Commander 12 requires Node.js v18 or higher, so users on older Node.js versions must upgrade Node.js before using this release. github.com
• Removed default
  The default export of a global Command instance from CommonJS was removed; switch to the named program export or create a new Command. github.com
• Behavior changed
  When a spawned executable subcommand terminates due to a signal, the parent now exits with a non-zero exit code, which can change scripts that expected success. github.com
• Behavior changed addCommand
  Adding a command whose name or alias is already in use now throws, so programs with duplicate command names must be fixed. github.com
• Behavior changed option
  Adding an option whose flag is already in use by another option now throws, so programs with duplicate flags must be fixed. github.com
• Behavior changed storeOptionsAsProperties
  Calling storeOptionsAsProperties after an option value has been set now throws an error; call it before setting option values. github.com
• Signature changed Command.addHelpCommand
  Was addHelpCommand(enableOrNameAndArgs?: string | boolean, description?: string): this; now addHelpCommand(cmd: Command): this addHelpCommand(enable?: boolean): this addHelpCommand(nameAndArgs: string, description?: string): this. npmjs.com

Check your code

These are the changes. To see which of them reach your code, scan a public repository, or have your coding agent call check_code with your manifest or lockfile over MCP. The API reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys.