I didn't really understand the "long task" thing until I actually experienced it. The problem is finding a task you can set an agent that justifies working for that long. I finally hit one when I tried porting that Python HTML5 parser to JavaScript by pointing Codex CLI at the 9,200 html5lib-tests test suite: https://simonwillison.net/2025/Dec/15/porting-justhtml/
It's pretty amazing to watch tools-in-a-loop crunch away for >4 hours to solve a generally difficult problem through sheer brute-force.
It's pretty amazing to watch tools-in-a-loop crunch away for >4 hours to solve a generally difficult problem through sheer brute-force.