main_first_positional_parameter_type

The type of the first positional parameter of the 'main' function must be a supertype of 'List'.

The analyzer produces this diagnostic when the first positional parameter of a function named main isn't a supertype of List<String>.

The following code produces this diagnostic because List<int> isn't a supertype of List<String>:

void main(List<int> args) {}

If the function is an entry point, then change the type of the first positional parameter to be a supertype of List<String>:

void main(List<String> args) {}

If the function isn't an entry point, then change the name of the function:

void f(List<int> args) {}

Unless stated otherwise, the documentation on this site reflects Dart 3.8.1. Page last updated on 2025-05-08. View source or report an issue.