Frappe Syntax Hooks Events

What it does

When your agent uses it

• Implementing document lifecycle hooks via docevents in hooks.py
• Understanding event execution order
• Extending/overriding document behavior from another app

Example prompts

• “/frappe-syntax-hooks-events”

Requirements

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

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

1. 1Controller method runs first (def validate(self))
2. 2doc_events handlers run in app installation order
3. 3Wildcard "*" handlers run after specific DocType handlers

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

  No scripts in the folder and no shell commands in SKILL.md (its code samples are python).

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

• Network

  Links to these hosts (documentation or services it may open):

  • docs.frappe.io

  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 Syntax Hooks Events loads about 3.1k tokens when it runs, and up to ~8.5k if it reads all its reference files. Until then it costs about 174 tokens; SKILL.md has 1,013 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~174

When it runs · the whole SKILL.md, loaded when a task matches

~3.1k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~8.5k

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

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). 1,013 words, ~3,117 tokens.

name

frappe-syntax-hooks-events

description

Use when implementing document lifecycle hooks via doc_events in hooks.py, understanding event execution order, or extending/overriding document behavior from another app. Prevents silent hook failures from wrong event names, incorrect execution order assumptions, and broken override chains. Covers doc_events hook syntax, all document events (before_insert, validate, on_submit, etc.), event execution order, extend vs override behavior, cross-app doc_events. Keywords: doc_events, hooks.py, before_insert, validate, on_submit, on_cancel, lifecycle, document events, override, extend, event order, which event fires when, before_save vs validate, document event list..

compatibility

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

license

MIT

metadata.author

OpenAEC-Foundation

metadata.version

2.0

# hooks.py
doc_events = {
    "Sales Invoice": {
        "on_submit": "myapp.events.sales_invoice.on_submit",
        "on_cancel": "myapp.events.sales_invoice.on_cancel",
    },
    "Purchase Order": {
        "validate": "myapp.events.purchase_order.validate",
    }
}

doc_events = {
    "*": {
        "after_insert": "myapp.events.global_handler.after_insert_all",
        "on_update": "myapp.events.global_handler.track_changes",
    }
}

doc_events = {
    "Sales Invoice": {
        "on_submit": [
            "myapp.events.accounting.create_gl_entries",
            "myapp.events.notifications.send_invoice_email",
        ]
    }
}

# myapp/events/sales_invoice.py
def on_submit(doc, method=None):
    """
    doc    — the Document instance (e.g., Sales Invoice)
    method — string name of the event (e.g., "on_submit"), or None
    """
    if doc.grand_total > 10000:
        frappe.sendmail(...)

extend_doctype_class = {
    "Sales Invoice": [
        "myapp.overrides.sales_invoice.SalesInvoiceExtension"
    ]
}

# myapp/overrides/sales_invoice.py
import frappe

class SalesInvoiceExtension:
    def validate(self):
        """This is called as part of the controller chain."""
        if self.grand_total < 0:
            frappe.throw("Grand total cannot be negative")

    def custom_method(self):
        """Custom methods are also available on the doc instance."""
        return self.items

# hooks.py
override_doctype_class = {
    "ToDo": "myapp.overrides.todo.CustomToDo"
}

# myapp/overrides/todo.py
from frappe.desk.doctype.todo.todo import ToDo

class CustomToDo(ToDo):
    def validate(self):
        super().validate()  # ALWAYS call super() to preserve original logic
        # Your additions here

© 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/syntax/frappe-syntax-hooks-events of Impertio-Studio/Frappe_Claude_Skill_Package.

• SKILL.md
• references/.gitkeep
• references/anti-patterns.md
• references/event-order.md
• references/examples.md

Open the folder on GitHubat commit 36cfa80