SeleniumHQ/selenium · error · Error

Unrecognized command: ${command.getName()}

Error message

Unrecognized command: ${command.getName()}

What it means

Thrown as a generic Error by webdriver.http.Executor.execute() when a Command's name does not match any entry in the executor's customCommands_ map or the static COMMAND_MAP_. The executor looks up the command name to obtain its HTTP method and path template; if neither source has it, the command is unrecognized and cannot be sent over the wire. This is from the legacy javascript/webdriver (Closure-based) HTTP layer.

Source

Thrown at javascript/webdriver/http/http.js:110

 * @param {string} name The command name.
 * @param {string} method The HTTP method to use when sending this command.
 * @param {string} path The path to send the command to, relative to
 *     the WebDriver server's command root and of the form
 *     "/path/:variable/segment".
 */
webdriver.http.Executor.prototype.defineCommand = function(
    name, method, path) {
  this.customCommands_[name] = {method: method, path: path};
};


/** @override */
webdriver.http.Executor.prototype.execute = function(command) {
  var resource =
      this.customCommands_[command.getName()] ||
      webdriver.http.Executor.COMMAND_MAP_[command.getName()];
  if (!resource) {
    throw new Error('Unrecognized command: ' + command.getName());
  }

  var parameters = command.getParameters();
  var path = webdriver.http.Executor.buildPath_(resource.path, parameters);
  var request = new webdriver.http.Request(resource.method, path, parameters);

  var log = this.log_;
  log.finer(function() {
    return '>>>\n' + request;
  });

  return this.client_.send(request).then(function(response) {
    log.finer(function() {
      return '<<<\n' + response;
    });
    return webdriver.http.Executor.parseHttpResponse_(
          /** @type {!webdriver.http.Response} */ (response));
  });

View on GitHub (pinned to aa36b38e69)

Solutions

1. Check that the command name string exactly matches a name registered in webdriver.http.Executor.COMMAND_MAP_ or previously added via defineCommand().
2. If using a custom endpoint, register it first: executor.defineCommand('myCommand', 'POST', '/session/:sessionId/my-command').
3. Verify the command name constant exists in the version of the library you are using — consult the command.Name enumeration.

Example fix

// before
executor.execute(new webdriver.command.Command('NonexistentCommand'))

// after
executor.defineCommand(
  'MyCustomCommand', 'POST', '/session/:sessionId/custom'
)
executor.execute(
  new webdriver.command.Command('MyCustomCommand')
)

const known = Object.assign(
  {}, executor.customCommands_,
  webdriver.http.Executor.COMMAND_MAP_
)
if (command.getName() in known) {
  executor.execute(command)
}

try {
  executor.execute(command)
} catch (e) {
  if (/Unrecognized command/.test(e.message)) {
    // register the command or fix the name
  } else throw e
}

When it happens

Trigger: Calling executor.execute(command) where command.getName() returns a string that was never registered via defineCommand() and is not part of the built-in COMMAND_MAP_. This happens when constructing a Command with a misspelled or non-existent command name.

Common situations: Using a command name that does not exist in the W3C/legacy WebDriver command set; referencing a custom command that was never registered via defineCommand(); a typo in the command name constant; version mismatch where a command was renamed or removed.

Related errors

• Missing required parameter: ${key}
• events should be string or string array
• browsingContexts should be string or string array
• Params must be an instance of AddInterceptParameters. Receiv
• Params must be an instance of ContinueRequestParameters. Rec

AI-assisted analysis of SeleniumHQ/selenium@aa36b38e69 (2026-08-14). Data as JSON: /api/errors/9e348cfd72d344db. Report an issue: GitHub.