Show HN: Greger.el – Agentic Coding in Emacs
4 fagerhult 2 7/2/2025, 11:14:43 AM github.com ↗
I was torn between using my beloved Emacs or using coding agents in Claude Code and Cursor. So I decided to have my cake and eat it.
Greger uses Claude with a set of built-in tools for editing code, running shell commands, searching the internet, etc. It also has a simple interface for adding custom tools.
The entire chat is a plain Emacs buffer, with markdown-like syntax. Which means that you can yank and kill and edit it like any other text file.
Every file that Greger changes gets tracked as a separate commit in Git, so you can roll back if it goes off the rails.
Most of Greger was written in Greger, with some light human review and refactoring. Claude is okay at Lisp, but I had to add a check for parens balance before accepting Claude's edits.
My main design goal was to have the whole chat described by a text buffer, that can be converted back and forth to the Claude dialog format. I love Emacs' built-in `shell-mode` because I can jump around in the shell buffer, kill and yank, etc. I wanted that same interaction model in the agent interface. I ended up writing a tree-sitter grammar and maybe going a bit over the top...
Also, I wanted something very hackable, where the entire codebase is in elisp. Claudemacs has the benefit of building on Claude Code, so it gets all the Claude Code features for free, whereas I have to implement everything from scratch. But I think of Greger as an experiment surface for novel agent patterns.
I don't think anyone has really figured out how to get the most of out agents yet, so it's great that we're all attacking it from different angles and taking inspiration from each other.