Tell erpfly what your ERPNext should do. It writes the Frappe app, installs it on a copy of your site, and opens a pull request when you’re happy with it.
Two ways in
Build
For processes ERPNext doesn’t cover: rentals, calibration, inspections, your own customer portal. You get an app that installs with bench and has its own DocTypes, logic, reports and tests.
ERPNext module development
Customize
For changes to Sales Order, Item, Employee and the rest. Everything is exported as fixtures inside a small app, so staging and production end up with the same fields and rules.
ERPNext customization
Example requests
Typical requests, written the way people type them. Underneath each one, what ends up in the frappe app.
Block submitting a Sales Order when the customer is on credit hold, unless an Accounts Manager does it.
A Check field on Customer, a before_submit hook on Sales Order, a role check and a test for both paths.
Sales order module ›Sync our ZKTeco punches into Employee Checkin every 15 minutes.
A settings DocType for device IPs, a scheduler_events entry in hooks.py, and an Error Log entry when a device doesn’t answer.
Attendance module ›Bin locations inside each warehouse, and pick lists sorted by walking order.
A Bin Location DocType linked to Warehouse, a field on Pick List Item, and a sort applied when the pick list is created.
Warehouse module ›A tax invoice print format with our bank details and the HSN code on every line.
A Print Format in Jinja shipped as a fixture, using the item’s gst_hsn_code and the company’s default bank account.
Invoice module ›Tools have calibration due dates. A job card can’t start if one of its tools is overdue.
A Tool Calibration DocType, a validate hook on Job Card, and a daily job that emails the maintenance lead a week ahead.
Manufacturing module ›Machine rentals with deposits and a damage check on return.
Submittable Rental Booking and Damage Inspection DocTypes, a Sales Invoice made on return, and a report of machines out today.
Custom ERPNext apps ›Fits your setup
app_name = "credit_hold"
app_title = "Credit Hold"
required_apps = ["erpnext"]
doc_events = {
"Sales Order": {
"before_submit": "credit_hold.sales_order.check_credit_hold",
}
}
fixtures = [
{"dt": "Custom Field", "filters": [["module", "=", "Credit Hold"]]},
{"dt": "Property Setter", "filters": [["module", "=", "Credit Hold"]]},
]The pull request is an ordinary Frappe app. Your developer runs bench get-app with the repository URL, installs it on the site, and runs bench migrate on later updates. Nothing about how your bench is set up has to change.
Custom apps need a private bench group on Frappe Cloud. Connect the GitHub repository to the bench, deploy, then install the app on your site. Shared benches only offer apps from the marketplace, so this is the one setting to check before you start.
Changes made in Customize Form live only in one site’s database. erpfly exports them as fixtures inside the app, so Custom Fields, Property Setters and Workflows reach staging and production the same way, and a move from v15 to v16 doesn’t leave half of them behind.
Upgrading without losing customizations ›Server Scripts are fine for a one-line rule. They are switched off by default on self-hosted benches, can’t import libraries and don’t come with tests. As soon as a change touches more than one DocType, erpfly writes an app instead.
Server Scripts vs a custom app ›How it works
In your own words. Paste the spreadsheet or a photo of the paper form if that's easier.
It asks only what it can't work out from your setup, like who's allowed to override.
A copy of your site with the module installed. Break it, then ask for changes.
Code lands as a pull request with tests. Your developer, or ours, reviews it first.
Module library
Every one of these can be built as a frappe app. Open one to see what gets generated, then describe your version.
Guides
The official documentation and source code this page was checked against.
Glossary
Something missing? Email [email protected] and a person will answer.
Yes, as long as the site is on a private bench group. Custom apps can’t be installed on shared benches. You connect the repository erpfly pushes to, deploy the bench, and install the app on your site.
Yes. It adds Custom Fields and Property Setters, hooks into document events from hooks.py, and exports all of it as fixtures. It never edits files inside the erpnext or frappe apps, so updates don’t overwrite your changes.
ERPNext and Frappe v15 and v16. You pick the version before you start, because the generated code targets that version exactly. If you’re on v14 or older, plan the upgrade first.
Yes. When you connect a staging site, erpfly reads the installed apps and their DocTypes, and lists the ones your new app depends on in required_apps. HRMS has been a separate app since v14, so HR changes build on it rather than on ERPNext.
It opens the erpfly builder with your description, the ERPNext version and the Build or Customize choice already filled in. Nothing is generated until you sign in and confirm.
Running Odoo instead? The same chat builds and customizes Odoo too. Last updated .
Write it the way you’d explain it to a new hire. We’ll turn it into an app you can read, test and install.