Advanced Customization in CRM/Lending apps with forward compatibility

[Heshan_Karunaratne]

Hi everyone,
We are starting a project using Frappe, specifically the CRM Portal and Lending apps. Most of the basic features are perfect for us, but we need to make some significant and deep changes.
I know Frappe recommends building a separate Custom App for our changes so we can easily update the official apps later (forward compatibility).
However, the specific customizations we need seem too invasive to manage easily in a custom app. I’m worried about breaking things when we update the core apps.
Our Main Customization Needs:

1. Rename Core Items: We need to rename the actual DocTypes and pages for things like Leads and Deals. We also need to remove, rename, or add many fields to the core Lead and Deal DocTypes.

2. Advanced Tasks: We need a complex Task system where the popup window (the Task Modal UI) changes completely based on what Task Type is selected.

3. Automation: We plan to use Workflows and scripts heavily for things like automating the Lead-to-Deal conversion process.

4. UI - Create new Pages written in vue utilizing the Frappe backend, and render within CRM Porta or Lending apps

The Problem:
When I try to do these changes using the recommended custom app method, it seems almost impossible or super complicated to maintain. Doing it by modifying the official app files directly works, but then we can’t update easily
My Questions to the Forum:

• Is this level of deep customization (especially renaming core DocTypes or altering the Task UI behavior) normal or supported for Frappe apps?

• Am I missing a standard, easy way to make these big changes while keeping the ability to update the official apps smoothly?

• What is the community’s best practice for managing these invasive customizations without getting stuck on an old version?

• For those who have heavily customized core apps - Do you rely on Fixtures/Hooks, or did you end up forking the apps?

Any advice on handling deep customization for Frappe’s core apps would be appreciated!
Thanks!

[Yamen_Zakhour]

Renaming doctypes will not work, other customizations are doable check this

Overriding Frappe UI: A Step-by-Step Guide with Explanations

Overriding Frappe UI: A Step-by-Step Guide with Explanations This guide focuses on overriding the Frappe CRM app, inspired by Safwan Erooth’s tutorial https://www.youtube.com/watch?v=OKrGJa2NnIs. It explains how and why to extend or modify Frappe’s CRM module UI for your custom requirements. We’ve also included a reference to the Frappe CRM GitHub repository and a screenshot of the CRM app UI for better context. [Screenshot from 2024-12-23 15-21-38] Prerequisites Ensure you have the follo…

Suggestion: do not try to rename the doctypes, instead change the labels on the Vue frontend.

[Heshan_Karunaratne]

@Yamen_Zakhour

ctypes, instead change the labels on the Vue frontend.

Thanks for the quick response. I’ll give it a try and see if it works for us.
Our initial plan was to rename the doctypes to maintain consistency across our apps. For now, we can proceed without renaming them. However, we do need to add new fields or modify the existing field properties within those doctypes. Is it possible to achieve this using the custom app approach?

[Yamen_Zakhour]

No you will break all controllers logic and api calls from the frontend. That will require a fork and then for future updates you will need to manually merge