Agent skill

Frappe Impl Customapp

by Impertio-Studio in Impertio-Studio/Frappe_Claude_Skill_Package

A skill your agent uses when building a custom Frappe app from scratch.

MITAuto-check passed

Install Frappe Impl Customapp

skills CLI
$ npx skills add Impertio-Studio/Frappe_Claude_Skill_Package --skill frappe-impl-customapp -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install Impertio-Studio/Frappe_Claude_Skill_Package frappe-impl-customapp --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/Impertio-Studio/Frappe_Claude_Skill_Package.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/source/impl/frappe-impl-customapp .claude/skills/frappe-impl-customapp && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
frappe-impl-customapp
GitHub stars
187
Token cost
~2.8k tokens
SKILL.md length
532 words
Files
5 (incl. references)
Skills in repo
61
Repo updated
First seen
Licence
MIT

At a glance

A skill your agent uses when building a custom Frappe app from scratch.

  • Works in 12 steps: Create App Structure → Configure pyproject.toml (v15+) → Configure hooks.py → …
  • Building a custom Frappe app from scratch
  • SKILL.md covers Main Decision: Do You Need a…, Step 1: Create App Structure, Step 2: Configure… and Step 3: Configure hooks.py, plus 10 more sections
  • Calls git; reaches github.com

What it does

Frappe Impl Customapp is an agent skill from Impertio-Studio/Frappe_Claude_Skill_Package. Use when building a custom Frappe app from scratch. Covers bench new-app walkthrough, app structure decisions, adding DocTypes, hooks, patches, fixtures management, development workflow (bench migrate, build, clear-cache), testing, packaging, installing on another site, version management, and app dependencies for v14/v15/v16. Keywords: create custom app, new frappe app, bench new-app, app structure, module creation, doctype creation, fixtures, patches, deployment, packaging, data migration, patch file…

Its SKILL.md is about 2.8k tokens, which your agent loads only when the skill is triggered. The skill folder holds 5 other files, including reference files (for example `references/anti-patterns.md`, `references/decision-tree.md` and `references/examples.md`). Compatibility notes: Claude Code, Claude.ai Projects, Claude API. Frappe v14-v16.

The repository describes itself as: 60 deterministic Claude AI skills for Frappe Framework & ERPNext v14-v16 development and operations. The licence is MIT.

When your agent uses it

  • Building a custom Frappe app from scratch

Example prompts

  • “/frappe-impl-customapp”

Requirements

  • Python 3
  • Compatibility (from SKILL.md): Claude Code, Claude.ai Projects, Claude API. Frappe v14-v16.

Workflow steps

12 steps, taken from the step headings in SKILL.md.

  1. Create App Structure
  2. Configure pyproject.toml (v15+)
  3. Configure hooks.py
  4. Define Modules
  5. Install and Create DocTypes
  6. Add Hooks
  7. Add Patches
  8. Fixtures Management
  9. Development Workflow
  10. Testing the App
  11. Packaging for Distribution
  12. App Dependencies

What it can do on your machine

Read from SKILL.md and the folder at commit 36cfa80. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Shell commands in SKILL.md call:

    • git

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Hosts in commands or code, which the agent is likely to contact:

    • github.com

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

  • Compatibility

    Claude Code, Claude.ai Projects, Claude API. Frappe v14-v16.

    From compatibility in the SKILL.md frontmatter.

Context cost

Frappe Impl Customapp loads about 2.8k tokens when it runs, and up to ~26k if it reads all its reference files. Until then it costs about 151 tokens; SKILL.md has 532 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~151
When it runs · the whole SKILL.md, loaded when a task matches
~2.8k
With references · SKILL.md plus every file in references/, read only if the agent opens them
~26k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from Impertio-Studio/Frappe_Claude_Skill_Package at commit 36cfa80, republished under its MIT licence (© Impertio-Studio). 532 words, ~2,774 tokens.

Download SKILL.mdSave it as .claude/skills/frappe-impl-customapp/SKILL.md (or your agent's skills folder). This skill also uses 4 other files; get the full folder from GitHub.
name
frappe-impl-customapp
description
Use when building a custom Frappe app from scratch. Covers bench new-app walkthrough, app structure decisions, adding DocTypes, hooks, patches, fixtures management, development workflow (bench migrate, build, clear-cache), testing, packaging, installing on another site, version management, and app dependencies for v14/v15/v16. Keywords: create custom app, new frappe app, bench new-app, app structure, module creation, doctype creation, fixtures, patches, deployment, packaging, data migration, patch file, patches.txt, migrate data between DocTypes, create new app from scratch.
compatibility
Claude Code, Claude.ai Projects, Claude API. Frappe v14-v16.
license
MIT
metadata.author
OpenAEC-Foundation
metadata.version
2.0

Frappe Custom App - Implementation

Workflow for building a custom Frappe app from scratch. For exact syntax, see frappe-syntax-customapp.

Version: v14/v15/v16 compatible


Main Decision: Do You Need a Custom App?

WHAT CHANGES DO YOU NEED?
|
+-- Add fields to existing DocType?
|   +-- NO APP NEEDED: Custom Field + Property Setter
|
+-- Simple automation/validation (<50 lines)?
|   +-- NO APP NEEDED: Server Script or Client Script
|
+-- Complex business logic, new DocTypes, or Python code?
|   +-- YES: Create custom app
|
+-- Integration with external system (needs imports)?
|   +-- YES: Custom app REQUIRED (Server Scripts block imports)
|
+-- Custom reports with complex queries?
|   +-- Script Report (no app) vs Query Report (app optional)

Rule: ALWAYS start with the simplest solution. Server Scripts + Custom Fields solve 70% of needs without a custom app.


Step 1: Create App Structure

bash
cd ~/frappe-bench
bench new-app my_app
# Prompts: Title, Description, Publisher, Email, License

ALWAYS verify immediately:

python
# my_app/my_app/__init__.py MUST have:
__version__ = "0.0.1"

Step 2: Configure pyproject.toml (v15+)

toml
[build-system]
requires = ["flit_core >=3.4,<4"]
build-backend = "flit_core.buildapi"

[project]
name = "my_app"
authors = [{ name = "Your Company", email = "dev@example.com" }]
description = "Your app description"
requires-python = ">=3.10"
readme = "README.md"
dynamic = ["version"]
dependencies = [
    "requests>=2.28.0"   # Only PyPI packages here
]

[tool.bench.frappe-dependencies]
frappe = ">=15.0.0,<16.0.0"
# erpnext = ">=15.0.0,<16.0.0"  # Only if needed

Rule: NEVER put frappe or erpnext in [project].dependencies -- they are NOT on PyPI.


Step 3: Configure hooks.py

python
app_name = "my_app"
app_title = "My App"
app_publisher = "Your Company"
app_description = "Description"
app_email = "dev@example.com"
app_license = "MIT"

required_apps = ["frappe"]  # Or ["frappe", "erpnext"]

fixtures = []  # Configured later

Rule: ALWAYS declare required_apps with all dependencies.


Step 4: Define Modules

text
# my_app/my_app/modules.txt
My App
App SizeModule Strategy
1-5 DocTypesONE module with app name
6-15 DocTypes2-4 modules by functional area
15+ DocTypesModules by business domain

Rule: Each DocType belongs to EXACTLY one module. Module name in modules.txt maps to directory: My Custom App --> my_custom_app/.

Adding a Module
bash
mkdir -p my_app/my_app/new_module/doctype
touch my_app/my_app/new_module/__init__.py
# Add "New Module" to modules.txt
bench --site mysite migrate

Step 5: Install and Create DocTypes

bash
# Install app on site
bench --site mysite install-app my_app

# Create DocType (via UI recommended, or CLI)
bench --site mysite new-doctype "My Document" --module "My App"

This creates:

my_app/my_app/doctype/my_document/
+-- my_document.json    # DocType definition
+-- my_document.py      # Controller
+-- my_document.js      # Client script
+-- test_my_document.py # Tests

Step 6: Add Hooks

doc_events (v14/v15/v16)
python
doc_events = {
    "Sales Invoice": {
        "validate": "my_app.events.sales_invoice.validate",
        "on_submit": "my_app.events.sales_invoice.on_submit"
    }
}
extend_doctype_class (v16 ONLY -- preferred)
python
extend_doctype_class = {
    "Sales Invoice": "my_app.overrides.sales_invoice.CustomSalesInvoice"
}

Rule: ALWAYS call super().method() when overriding lifecycle methods in v16.

Scheduler Events
python
scheduler_events = {
    "daily": ["my_app.tasks.daily_cleanup"],
    "cron": {"0 9 * * 1-5": ["my_app.tasks.morning_report"]}
}

See frappe-impl-hooks and frappe-impl-scheduler for complete patterns.


Step 7: Add Patches

Create Patch File
bash
mkdir -p my_app/my_app/patches/v1_0
touch my_app/my_app/patches/__init__.py
touch my_app/my_app/patches/v1_0/__init__.py
python
# my_app/my_app/patches/v1_0/populate_defaults.py
import frappe

def execute():
    if not frappe.db.has_column("My DocType", "target_field"):
        return  # Skip if not applicable

    batch_size = 1000
    offset = 0
    while True:
        records = frappe.get_all("My DocType",
            limit_page_length=batch_size, limit_start=offset)
        if not records:
            break
        for r in records:
            frappe.db.set_value("My DocType", r.name,
                "target_field", "default", update_modified=False)
        frappe.db.commit()
        offset += batch_size
Register in patches.txt
ini
[pre_model_sync]
# Patches that run BEFORE schema changes (backup data from deleted fields)

[post_model_sync]
# Patches that run AFTER schema changes (populate new fields)
my_app.patches.v1_0.populate_defaults

Rules:

  • ALWAYS check if patch is needed (guard clause)
  • ALWAYS batch process 1000+ records
  • ALWAYS commit after each batch
  • NEVER run untested patches on production

Step 8: Fixtures Management

Configure in hooks.py
python
fixtures = [
    {"dt": "Custom Field", "filters": [["module", "=", "My App"]]},
    {"dt": "Property Setter", "filters": [["module", "=", "My App"]]},
    {"dt": "Role", "filters": [["name", "in", ["My App User", "My App Manager"]]]},
    {"dt": "Workflow", "filters": [["document_type", "=", "My DocType"]]},
    "My Category",  # All records of your own config DocType
]
Export and Verify
bash
bench --site mysite export-fixtures --app my_app
ls my_app/my_app/fixtures/
# custom_field.json, property_setter.json, etc.

Rules:

  • ALWAYS filter fixtures to YOUR app's customizations
  • NEVER include transactional data (invoices, orders)
  • NEVER export without filters for shared DocTypes (Custom Field, Workflow)
  • Fixtures auto-import during bench migrate

Step 9: Development Workflow

Essential Commands
bash
# After schema changes (DocType fields, hooks.py, patches)
bench --site mysite migrate

# After JS/CSS changes
bench build --app my_app

# After Python changes (controllers, events)
bench --site mysite clear-cache

# Full restart (production)
bench restart

# Watch mode (development)
bench watch  # Auto-rebuilds on file changes
Development Cycle
1. Edit code/DocType
2. bench --site mysite migrate (if schema changed)
3. bench build --app my_app (if JS/CSS changed)
4. bench --site mysite clear-cache (if Python changed)
5. Test in browser
6. Repeat

Step 10: Testing the App

bash
# Run all tests
bench --site mysite run-tests --app my_app

# Run specific test
bench --site mysite run-tests --module my_app.my_module.doctype.my_doctype.test_my_doctype

# Run with verbose output
bench --site mysite run-tests --app my_app -v

See frappe-testing-unit for writing test cases.


Step 11: Packaging for Distribution

Via Git (standard method)
bash
cd apps/my_app
git init && git add . && git commit -m "Initial commit"
git remote add origin https://github.com/org/my_app.git
git push -u origin main
Install on Another Site
bash
# On target bench
bench get-app https://github.com/org/my_app.git
bench --site target-site install-app my_app
bench --site target-site migrate
Version Management
python
# my_app/my_app/__init__.py
__version__ = "1.0.0"  # Semantic versioning: MAJOR.MINOR.PATCH
Change TypeVersion BumpExample
Breaking changesMAJOR1.x -> 2.0.0
New featuresMINOR1.1.x -> 1.2.0
Bug fixesPATCH1.2.0 -> 1.2.1

Step 12: App Dependencies

Frappe/ERPNext Dependencies
python
# hooks.py
required_apps = ["frappe", "erpnext"]  # Install order matters
toml
# pyproject.toml
[tool.bench.frappe-dependencies]
frappe = ">=15.0.0,<16.0.0"
erpnext = ">=15.0.0,<16.0.0"
Python Package Dependencies
toml
[project]
dependencies = ["requests>=2.28.0", "pandas>=1.5.0"]

Rule: NEVER create circular dependencies between apps.


Show full SKILL.md (216 more words)Show less

Version-Specific Considerations

Aspectv14v15v16
Build configsetup.pypyproject.tomlpyproject.toml
DocType extensiondoc_eventsdoc_eventsextend_doctype_class preferred
Python minimum3.103.103.11
Patch formatINI sectionsINI sectionsINI sections
v16 Breaking Changes to Know
  • extend_doctype_class hook: Cleaner extension via mixins
  • Data masking: Field-level privacy configuration
  • UUID naming: New naming rule option
  • Chrome PDF: wkhtmltopdf deprecated

Critical Rules Summary

ALWAYS
  1. Start with bench new-app - NEVER create structure manually
  2. Define __version__ in __init__.py
  3. Use dynamic = ["version"] in pyproject.toml
  4. Test patches on database copy before production
  5. Filter fixtures to your app's customizations only
  6. Version your patches (v1_0, v2_0 directories)
  7. Test installation on a fresh site
NEVER
  1. Put frappe/erpnext in [project].dependencies
  2. Include transactional data in fixtures
  3. Hardcode site-specific values (use settings DocTypes)
  4. Skip frappe.db.commit() in large patches
  5. Delete fields without backup patch
  6. Modify core ERPNext files directly

Reference Files

FileContents
workflows.md8 step-by-step implementation guides
decision-tree.mdComplete decision flowcharts
examples.md5 complete working app examples
anti-patterns.mdCommon mistakes to avoid

See Also

  • frappe-syntax-customapp - Exact syntax reference
  • frappe-syntax-hooks - Hooks configuration syntax
  • frappe-impl-hooks - Hook implementation patterns
  • frappe-core-database - Database operations for patches
  • frappe-impl-scheduler - Scheduled task implementation
  • frappe-ops-bench - Bench commands reference
  • frappe-ops-app-lifecycle - App versioning and release management
  • frappe-testing-unit - Writing tests for your app
  • frappe-testing-cicd - CI/CD pipeline for app testing

© Impertio-Studio, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 4 other files (references) in skills/source/impl/frappe-impl-customapp of Impertio-Studio/Frappe_Claude_Skill_Package.

  • SKILL.md
  • references/anti-patterns.md
  • references/decision-tree.md
  • references/examples.md
  • references/workflows.md

Open the folder on GitHubat commit 36cfa80

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Questions about Frappe Impl Customapp

What does Frappe Impl Customapp do?

A skill your agent uses when building a custom Frappe app from scratch. Frappe Impl Customapp is an agent skill from Impertio-Studio/Frappe_Claude_Skill_Package. Use when building a custom Frappe app from scratch.

When should I use Frappe Impl Customapp?

Frappe Impl Customapp fits situations like: building a custom Frappe app from scratch.

How do I install Frappe Impl Customapp in Claude Code?

Run `npx skills add Impertio-Studio/Frappe_Claude_Skill_Package --skill frappe-impl-customapp -a claude-code`. Or copy the skill folder (skills/source/impl/frappe-impl-customapp in Impertio-Studio/Frappe_Claude_Skill_Package) into .claude/skills/frappe-impl-customapp in your project. Claude Code loads it when a task matches its description.

How do I install Frappe Impl Customapp in Codex?

Run `npx skills add Impertio-Studio/Frappe_Claude_Skill_Package --skill frappe-impl-customapp -a codex`. Or copy the skill folder (skills/source/impl/frappe-impl-customapp in Impertio-Studio/Frappe_Claude_Skill_Package) into .agents/skills/frappe-impl-customapp in your project. Codex loads it when a task matches its description.

Can I use Frappe Impl Customapp in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add Impertio-Studio/Frappe_Claude_Skill_Package --skill frappe-impl-customapp -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/frappe-impl-customapp, .gemini/skills/frappe-impl-customapp, .github/skills/frappe-impl-customapp and .opencode/skills/frappe-impl-customapp in your project.

What does Frappe Impl Customapp need to run?

Going by SKILL.md and its folder, Frappe Impl Customapp needs the command-line tools its instructions call (git). Our summary lists: Python 3. Compatibility (from SKILL.md): Claude Code, Claude.ai Projects, Claude API. Frappe v14-v16..

Does Frappe Impl Customapp access the network?

SKILL.md names 1 domain. In commands or code: github.com; the agent is likely to contact it when it follows the instructions. This is read from the text; nothing was executed.

Is Frappe Impl Customapp safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Frappe Impl Customapp use?

Frappe Impl Customapp is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Frappe Impl Customapp use?

About 2.8k tokens (SKILL.md is roughly 11k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 24k tokens, read only when the agent opens those files.

What are the alternatives to Frappe Impl Customapp?

Skills that share tags, products or a category with Frappe Impl Customapp: Impl (tympanix/Electorrent, 1.2k stars), Kermt Pretrain Scratch (NVIDIA/skills, 3.5k stars), Dev Impl (classmethod/tsumiki, 974 stars) and Credit From Scratch (mohitagw15856/pm-claude-skills, 1.4k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Frappe Impl Customapp?

Impertio-Studio (a GitHub organization) maintains it in Impertio-Studio/Frappe_Claude_Skill_Package, which has 187 GitHub stars. The repository holds 61 skills in this directory. The repository was last updated on September 17, 2026.

Source: Impertio-Studio/Frappe_Claude_Skill_Package on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.