Introduction

This tutorial guides you through creating your first custom app using Frappe Framework v15—a full-stack, low-code platform that powers ERPNext.

Whether you’re a Python developer, ERP consultant, or a tech entrepreneur, this guide offers hands-on experience with Frappe’s modular architecture, DocType creation, scripting, and backend logic.

You’ll create a basic app to manage “Books” and understand how DocTypes, permissions, REST APIs, and front-end forms work in unison.

Core Sections

Overview

In this tutorial, you will:

• Create a custom Frappe app (library_management)
• Create a site and install the app
• Define custom DocTypes like Book and Library Member
• Add fields, relationships, and permissions
• Build backend logic and test APIs

By the end, you’ll have a functioning app with both backend and UI, powered by Frappe’s out-of-the-box features.

Installation / Setup

Prerequisites

Ensure you’ve followed the Frappe v15 Installation Guide.

Create and Setup Bench

bench init my-bench --frappe-branch version-15
cd my-bench
bench new-site library.local

Create Your First App

bench new-app library_management

Follow the CLI prompts:

• App Name: Library Management
• App Title: Library Management
• App Description: App for managing library resources
• App Publisher: Your name/company
• Email, license, etc.

Install App on Site

bench --site library.local install-app library_management

Start Development Server

bench start

Access: http://localhost:8000
Login with Administrator credentials you set during new-site.

Configuration

Navigate to Library Management > Library Management > DocType in the UI.

Create a New DocType: Book

• Name: Book
• Module: Library Management
• Check “Is Submittable”
• Add Fields:
  • title → Data
  • author → Data
  • isbn → Data
  • status → Select (Available, Issued)

Save and reload.

Create Another DocType: Library Member

• first_name → Data
• last_name → Data
• email_id → Data
• membership_expiry_date → Date

Functional Use

Now your app has two main DocTypes:

• Book: Manages book inventory
• Library Member: Tracks members

You can:

• Add records using the web UI
• Link them together
• Assign roles and permissions

Frappe auto-generates forms, list views, and REST APIs.

Developer Reference / API

To fetch records via REST:

GET /api/resource/Book

To create a new Book via API:

curl -X POST https://library.local/api/resource/Book \
-H "Authorization: token <api_key>:<api_secret>" \
-H "Content-Type: application/json" \
-d '{
"title": "The Alchemist",
"author": "Paulo Coelho",
"isbn": "978-0061122415",
"status": "Available"
}'

To add custom server logic, use hooks like:

# in library_management/library_management/book/book.py
def before_insert(self):
if not self.title:
frappe.throw("Title is required")

Practical Use Case

Scenario: A small-town library wants to digitize its book borrowing system. Instead of using spreadsheets, they deploy Frappe v15 and:

1. Create a custom app: Library Management
2. Define DocTypes: Book, Library Member, Borrow Entry
3. Add custom workflows for issuing/returning
4. Use print formats to generate receipts
5. Set automated email reminders for overdue returns

In just a few days, they build a tailored ERP solution—without licensing fees or coding from scratch.

Advanced Features

• Child Tables: Create a Borrowed Book child table linked to a Borrow Entry DocType
• Workflows: Add approval states for new book purchases
• Role Permissions: Restrict access to librarians only
• Print Formats: Design borrower receipts in Jinja templates

Tips, Best Practices & Pitfalls

Best Practices:

1. Use descriptive fieldnames and keep naming consistent.
2. Leverage client-side scripting only for UI—not validations.
3. Modularize Python logic and avoid fat Doctype classes.

Common Pitfalls:

• Skipping bench migrate after adding DocTypes = broken schema.
• Not creating separate apps = harder upgrades later.
• Overuse of custom scripts = security risks.

v15 Notes:

• Vue 3 is fully supported for frontend customization.
• DocType UI is faster and more responsive than previous versions.

Visual Suggestion

• Diagram: Frappe MVC Flow (Doctype → DB → API → UI)
• Screenshot: Custom DocType creation screen
• Workflow: Book Issuance Approval Flow

Conclusion

Frappe Framework v15 empowers you to quickly build full-featured business applications. With this tutorial, you’ve taken the first step into the Frappe ecosystem—equipped to create modular apps, manage business logic, and connect data across users and interfaces.