I created a script that outputs the entire codebase to a text file (also allows me to exclude files/folders/node_modules), separating and labeling each file in the program folder.

I then structure my prompts around like so:

<project_code> ``` ``` </project_code>

<heroku_errors> " " </heroku_errors>

<task> " " </task>

I've been using this with Google Ai studio and it's worked phenomenally. 1 million tokens is A LOT of code, so I'd imagine this would work for lots n lots of project type programs.

Repomix, there's a cli and an MCP.