What is yaffa copilot-instructions.md?

A set of Copilot instructions for Yaffa, a self-hosted personal finance web application built with Laravel, PHP, Vue, and MySQL. It describes the application structure, technology stack, tests, and code-quality checks.

Use it for Yaffa feature work, bug fixes, testing, and maintenance. It is especially relevant to PHP and Laravel backend code, Vue interfaces, and finance-related application features.

It gives a coding agent the application's purpose and technical context before it changes code. That reduces the risk of using the wrong framework conventions or breaking related parts of the app.

How kantorge/yaffa configures GitHub Copilot

Reuse

Borrowing it

Nothing to install: this file belongs to kantorge/yaffa. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/kantorge/yaffa/develop/.github/copilot-instructions.md

Clone the repo

git clone --depth 1 https://github.com/kantorge/yaffa

Made for: GitHub Copilot.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/kantorge/yaffa/copilot-instructions/github.svg)](https://agentmods.dev/instructions/kantorge/yaffa/copilot-instructions)

Your own site

<a href="https://agentmods.dev/instructions/kantorge/yaffa/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/kantorge/yaffa/copilot-instructions/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/kantorge/yaffa/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/kantorge/yaffa/copilot-instructions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 2,732 This file is loaded in full into every session.

When invoked 2,732 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.02732	$0.02732
Opus 5.5	$0.01093	$0.01093
Sonnet 5.5	$0.00546	$0.00546
Haiku 4.5	$0.00273	$0.00273

Measured 11d ago against content hash 68ddb06bed9b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

yaffa copilot-instructions.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.github/copilot-instructions.md · 285 lines

How it starts

The opening of the file, as written. The whole thing — 285 lines — stays where its author put it; the contents beside it link to each section on GitHub.

YAFFA - Coding Agent Instructions

Project Overview

YAFFA (Yet Another Free Financial Application) is a self-hosted personal finance web application built with Laravel 12 (PHP 8.4) and Vue 3. It helps users track income/expenses, manage multiple currencies, handle investments, and perform long-term financial planning. The application includes ~7,700 lines of PHP code across Controllers, Models, Services, and more.

Key Technologies:

Backend: PHP 8.4, Laravel 12 Framework
Frontend: Vue 3, Bootstrap 5, CoreUI, jQuery, DataTables
Build: Laravel Mix (Webpack), NPM
Testing: PHPUnit (Unit/Feature tests), Laravel Dusk (Browser tests)
Database: MySQL 8
Code Quality: Laravel Pint (PSR-12), PHPStan (Level 5), ESLint

Repository Structure

├── app/                    # Laravel application code
│   ├── Console/           # Artisan commands
│   ├── Http/Controllers/  # Request handlers
│   ├── Models/           # Eloquent models
│   ├── Services/         # Business logic (TransactionService, InvestmentService, etc.)
│   ├── Policies/         # Authorization logic
│   ├── Jobs/             # Queue jobs
│   └── Rules/            # Validation rules
├── resources/
│   ├── js/               # Vue 3 components and JavaScript
│   ├── views/            # Blade templates
│   └── sass/             # SCSS stylesheets
├── tests/
│   ├── Unit/             # Unit tests
│   ├── Feature/          # Feature tests
│   └── Browser/          # Laravel Dusk browser tests
├── config/               # Laravel configuration files
├── database/
│   ├── migrations/       # 43 database migration files
│   ├── factories/        # Model factories for testing
│   └── seeders/          # Database seeders (including demo.sql)
├── routes/
│   ├── web.php           # Web routes
│   ├── api.php           # API routes
│   └── breadcrumbs.php   # Breadcrumb definitions
├── docker/               # Docker deployment files
├── public/               # Public assets (CSS, JS - generated)
└── storage/              # Application storage (logs, cache)

Read the full file on GitHub · 285 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

11d ago First seen · 285 lines · 2,732 tokens per session scan A 68ddb06bed9b

Subscribe to this mod's changes

yaffa copilot-instructions.md is an instructions file published in the GitHub repository kantorge/yaffa (113 stars, last pushed today), licensed MIT. It adds 2,732 tokens to every session, about $0.0109 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-26.

Backend and APIs Finance and fintech

yaffa copilot-instructions.md next to 6 instructions from other repositories
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yaffa: Instructions file for GitHub Copilot