I think it depends on what you are trying to do.
The MCP is more of a thing that says “Hey, how many orders did we place to people in rainy climates” [or whatever]. You’re developing an AI module that queries the production content.
CODING an ERP app isn’t that - a Coding AI model would be something that understands Frappe and/or ERPNext itself. You don’t need an MCP, you just tell it to read the code on the disk (and with CoPilot, it does that anyway). It figures out you’re using ERPNext from your code.
In this case, I don’t have production data, I have an instance with test data in it, that’s not public (it’s on a VM in my Windows machine)
Frankly, I find most of the models are pretty close to full understanding of ERPNext. Unprompted, both Anthropic models suggested code in patches.txt, hooks.py, and other Frappe specific coding idioms.
I did have one generate some pre-version 15 code, and some of the internals have changed, so I had to add a context to my app.
This goes into a “copilot-instructions.md” (if you’re using copilot, for example):
## General Guidelines
- When generating Mermaid diagrams, use a placeholder language like ```text instead of ```mermaid, with a note to change
# Project Context
## Key Requirements
- ERPNext Version: v15
- Compatible with ERPNext version 16.
- Not backward compatible to other versions of ERPNext, but should be forward compatible with future versions as well.
- Target Users: <example sanitized>
- Compatible with ERPNext as well as Frappe HRMS for employee management and payroll.
## Architecture Decisions
- <examples sanitized>
This isn’t the same thing as writing docs; I have separate more detailed design specs. You can ask AI to read those, of course. Adding to the copilot-instructions.md means you don’t have to tell it to do that every time, and you can also fix bugs (it would consistently mess up Mermaid diagrams in my implementation plan)
My version kept giving API’s for far older versions of ERPNext, so that fixed it right up.
@ahassoun :
Has anyone written cursor rules? Looking for inspirations
So I haven’t really needed to. It intuitively understands to go look for the ERP docs. I just had to guide it to the correct version per my above.