We’re considering building a coding agent for Lowdefy[1], a framework that lets you build web apps with YAML config.

For those who’ve built coding agents: do you think LLMs are better suited for generating structured config vs. raw code?

My theory is that agents producing valid YAML/JSON schemas could be more reliable than code generation. The output is constrained, easier to validate, and when it breaks, you can actually debug it.

I keep seeing people creating apps with vibe coder tools but then get stuck when they need to modify the generated code.

Curious if others think config-based approaches are more practical for AI-assisted development.

[1] https://github.com/lowdefy/lowdefy

> easier to validate

This is essential to productivity for humans and LLMs alike. The more reliable your edit/test loop, the better your results will be. It doesn't matter if it's compiling code, validating yaml, or anything else.

To your broader question. People have been trying to crack the low-code nut for ages. I don't think it's solvable. Either you make something overly restrictive, or you are inventing a very bad programming language which is doomed to fail because professional coders will never use it.

Mine is a much simpler use case but sharing in case it's useful. I wanted to be able to quickly generate and iterate on user flows during design collaboration. So I use some boilerplate HTML/CSS and have the LLM generate an "outline" (basically a config file) and then generate the HTML from that. This way I can make quick adjustments in the outline and just have it refresh the code when needed to avoid too much back forth with the chat.

Overall, it has been working pretty well. I did make a tweak I haven't pushed yet to make it always writes the outline to a file first (instead of just terminal). And I've also started adding slash commands to the instructions so I can type things like "/create some flow" and then just "/refresh" (instead of "pardon me, would you mind refreshing that flow now?").

https://github.com/pglevy/breadboarding-kit

> For those who’ve built coding agents: do you think LLMs are better suited for generating structured config vs. raw code?

Raw code. Use case was configuring a mapping of health data JSON from heterogeneous sources to a standard (also JSON) format. Initial prototype was a YAML DSL, based on the same theory as yours. LLMs had difficulty using the DSL’s semantics correctly, or even getting its syntax (not YAML-level syntax, but the schema: nesting levels for different constructs, and so on). It’s possible that better error loops or something would have cracked it, but a second prototype generating jq worked so much better out of the box that we basically never looked back.

I wouldn’t get hung up on one shotting anything. Output to a format that can be machine verified, ideally in a format there is plenty of industry examples for.

Then add a grader step to your agentic loop that is triggered after the files are modified. Give feedback to the model if there any errors and it will fix them.

How do you specify callbacks?

Config files should be mature programming languages, not Yaml/Json files.