Check open-source implementations before coding

How to use it

Models / tools: Works with multiple models and tools

1. Add the rule to the project instructions you give your AI coding agent, such as AGENTS.md or CLAUDE.md.

What it can do

This is a coding rule Blake Young shared on X, suggesting that everyone who writes code with AI add it to their project prompt. The rule tells the AI that when it meets an unfamiliar feature, it should first search GitHub for actively maintained, clearly licensed open-source projects that do the same thing, compare their approaches, dependencies and known issues, prefer designs that have been proven, and avoid copying code that's incompatible or of unclear origin. The author says the rule has saved him a lot of rework. It's a single paragraph, and it governs what the AI does before it starts writing. Add the rule to the project instructions you give your AI coding agent, such as AGENTS.md or CLAUDE.md.

Who it is for

Developers who use AI coding agents and want fewer false starts.

Before you use it

The author doesn't name a model, so any common AI coding agent will do. The rule has the agent search GitHub first, so it needs web access. Check the licence yourself before reusing any open-source code. The author has not stated a reuse licence, so we show only the rule itself; see the author's post for his comments.

Follow the stated license. Do not use the output to replicate someone else’s work or a real person’s likeness.