[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$f36n1xdpon1xms":3},{"_id":4,"slug":5,"title":6,"subtitle":7,"kind":8,"cards":9,"tags":58,"categories":60,"source":62,"lang":65,"author":66,"audioState":69,"stats":70,"publishedAt":73,"renderer":74},"6abaedb3ca21c797c7e9b4e1","i-stopped-writing-separate-instructions-for-claude-code-code-5af0278f","I Stopped Writing Separate Instructions for Claude Code, Codex, and Cursor - Here's My 2026 Setup","AGENTS.md vs CLAUDE.md vs Cursor Rules vs Skills vs MCP: What Actually Belongs Where?","news",[10,14,19,24,29,33,38,43,48,53],{"headline":11,"body":12,"imageUrl":13,"sourceImageUrl":13},"I Stopped Writing Separate Instructions for Claude Code, Codex, and Cursor -…","AGENTS.md vs CLAUDE.md vs Cursor Rules vs Skills vs MCP: What Actually Belongs Where? AGENTS.md vs CLAUDE.md vs Cursor Rules vs Skills vs MCP: What Actually Belongs Where? I use multiple AI coding agents in my development workflow. Claude Code for some tasks. Codex for others. Cursor when I want to work directly inside the editor. At first, my approach was simple: Give each AI tool enough instructions to understand the project. That worked. Until it didn't. My repositories gradually started accumulating instructions everywhere: Many of these files contained overlapping information.","https:\u002F\u002Fmedia2.dev.to\u002Fdynamic\u002Fimage\u002Fwidth=1200,height=627,fit=cover,gravity=auto,format=auto\u002Fhttps%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2F80j05naoazp7pk24ie2l.png",{"headline":15,"body":16,"imageUrl":17,"images":18},"I was mixing project conventions, architecture decisions, feature","I was mixing project conventions, architecture decisions, feature requirements, and agent workflows into the same documents. Whenever I updated a rule, I had to remember where else I'd duplicated it. The problem wasn't necessarily that my agents needed more context. The problem was how I organized that context. So I started separating shared repository knowledge from tool-specific instructions and task-specific requirements.","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F1.webp",{"local":17},{"headline":20,"body":21,"imageUrl":22,"images":23},"This article explains the structure, why I use","This article explains the structure, why I use it, and how to avoid a subtle configuration problem when sharing instructions between Claude Code, Codex, and Cursor.","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F2.webp",{"local":22},{"headline":25,"body":26,"imageUrl":27,"images":28},"Important: This is my approach to organizing AI","Important: This is my approach to organizing AI development workflows, not a universal standard. Each coding agent has its own instruction discovery and configuration behavior. Always check your tool's current documentation.","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F3.webp",{"local":27},{"headline":25,"body":30,"imageUrl":31,"images":32},"Important: This is my approach to organizing AI development workflows, not a universal standard. Each coding agent has its own instruction discovery and configuration behavior. Always check your tool's current documentation. 1. The Problem: Every AI Agent Needs Context Imagine you're developing a production application using: Authentication and permissions Established architectural conventions You ask your coding agent: That sounds straightforward. But the agent needs answers to several questions.","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F4.webp",{"local":31},{"headline":34,"body":35,"imageUrl":36,"images":37},"Does the application already have a reusable filter","Does the application already have a reusable filter component? Are filters stored in URL parameters? Does the backend already support filtering? Where should data fetching happen? More importantly, which existing patterns should the agent preserve?","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F5.webp",{"local":36},{"headline":39,"body":40,"imageUrl":41,"images":42},"Without sufficient context, an agent might introduce a","Without sufficient context, an agent might introduce a second filtering system instead of extending the existing implementation.","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F6.webp",{"local":41},{"headline":44,"body":45,"imageUrl":46,"images":47},"That's where AI-generated code becomes expensive: not necessarily","That's where AI-generated code becomes expensive: not necessarily because the generated code is incorrect, but because it doesn't fit the existing system. 2. My First Mistake: The Giant Instruction File Initially, I tried solving this by putting almost everything into one instruction file. Eventually, the file became difficult to maintain.","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F7.webp",{"local":46},{"headline":49,"body":50,"imageUrl":51,"images":52},"The problem was that permanent instructions, temporary requirements","The problem was that permanent instructions, temporary requirements, and reference documentation were all competing for the same space. A small UI change didn't need deployment documentation. A backend bug didn't need animation guidelines. And a feature requirement shouldn't permanently live alongside repository-wide coding conventions. More context is not automatically better context. I needed a way to organize information according to its purpose. 3. The Mental Model I Use Now Instead of treating context as one giant document, I separate it into distinct responsibilities. Each layer answers a different question.","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F8.webp",{"local":51},{"headline":54,"body":55,"imageUrl":56,"images":57},"For example, repository instructions explain how an agent","For example, repository instructions explain how an agent should work, while feature intent explains what a particular change should accomplish. This distinction makes it easier to maintain context without repeating everything in every prompt. A note about compatibility","\u002Fapi\u002Fmedia\u002Fposts\u002Fi-stopped-writing-separate-instructions-for-claude-code-code-5af0278f\u002F9.webp",{"local":56},[59],"dev",[61],"Technology",{"name":63,"url":64},"Dev.to","https:\u002F\u002Fdev.to\u002Fnaelawadallah\u002Fi-stopped-writing-separate-instructions-for-claude-code-codex-and-cursor-heres-my-2026-setup-47ih","en",{"handle":67,"displayName":68},"spots","Spots","queued",{"views":71,"likes":72,"saves":72,"shares":72,"completions":72,"opens":72,"skips":72,"depthSum":72},3,0,"2026-09-28T22:44:03.840Z","local"]