ECC, explained: the free file that makes your AI code like a pro
In September 2025, at a New York hackathon co-hosted by Anthropic and Forum Ventures, a developer named Affaan Mustafa and his team built a working AI product in eight hours and won $15,000 in AI credits. Impressive, but not the interesting part.
The interesting part is how he worked. His AI coding assistant was not the same one everyone else had. It had been trained on the job: roughly ten months of daily tuning, corrections, and rules, all stored in a personal configuration for Claude Code, Anthropic's AI coding agent.
In January 2026 he published the whole thing, for free. It is called ECC, and it exploded:
What ECC actually is
Out of the box, an AI coding agent is a brilliant intern with no training: smart, fast, and clueless about how professionals actually work. ECC is the training manual. Three building blocks:
284 skills. Ready-made playbooks the AI follows for specific jobs: reviewing code, writing tests, deploying, debugging. Instead of improvising every time, it follows a checklist a senior engineer would recognize.
67 agents. Mini AI workers with one job each: a security reviewer, a test writer, a bug hunter. The main AI can delegate to them instead of doing everything itself.
94 commands. Shortcuts for the boring parts, so entire routines run from a single line. Plus built-in security scanning over what gets produced.
Install it safely, step by step
Install Claude Code
ECC is a configuration for Claude Code, so you need that first. One line in your terminal:
npm install -g @anthropic-ai/claude-code
Then run claude in any folder and sign in. If this is your first time in a terminal, go slowly; nothing here bites.
Go to the official page, and only the official page
Type the address yourself: github.com/affaan-m/ECC (the official site is ecc.tools). Check three things: the author is affaan-m, the star count is in the hundreds of thousands, and the license says MIT.
Run the installer from the official README
The README on the official repo has a one-line install command. Copy it from there, never from a video comment section, a DM, or a re-upload. That one habit is most of your protection against the malware clones (more below).
Take it for a test drive
Open a project and ask Claude Code to do something you would normally dread. Ask it to review your code for security problems, or to write tests for a file. Watch which skills it picks up; that is ECC working.
Review this project for security issues, then fix the three most important ones and explain what you changed.
Learn five skills, ignore the rest (for now)
Nobody uses 284 playbooks in week one. Skim the skills list in the README, pick the five that match your actual work, and get comfortable. The rest will be there when you need them.
ECC's popularity spawned clones, and some carry hidden malware. The rule is simple: the official repo is github.com/affaan-m/ECC and the official site is ecc.tools. Anything else, however similar the name, treat as hostile. If you already installed from somewhere else, remove it and change any keys it could have touched.
ECC gives your agent general craft. The part nobody can write for you is the file describing your project: your test command, your house rules, the traps that have caught people out. Our free CLAUDE.md generator asks six questions and hands you the file. It runs in your browser, so nothing about your project is uploaded.
One thing to know once that file exists: it is read at session start and held in memory, so editing it mid-session does not apply until your next /clear or restart. That, and five other habits that keep a session cheap, are in six habits that cut Claude Code token usage.
And once you are comfortable letting it drive, the same trick works on installs nobody enjoys doing by hand. One prompt gets it to set up a full local AI video generator, hardware check and all, in make AI videos on your own computer.
A config file is also how a job that repeats every week stays correct. A marketer at Anthropic runs a Monday send to every sales rep off a prompt that grew nine rules in its first week, one for each thing it got wrong — all nine are in the nine rules behind Anthropic’s Monday send.
Questions people actually ask
Is ECC really free?
Yes. It is open source under the MIT license, which means free for personal and commercial use. If a site asks you to pay for ECC, you are on a fake.
Do I need to know how to code?
No, but you need to be comfortable installing a terminal tool and following a README. If you can copy-paste carefully, you can set this up in an afternoon.
Does it work with tools other than Claude Code?
It is built for Claude Code first. Codex is supported, Cursor and OpenCode are in beta, and Gemini support is experimental. If you use Claude Code, you get the full experience.
Will it slow my AI down?
Skills load on demand, so you are not paying for all 284 playbooks on every request. In practice the AI gets slower per answer but much faster per finished task, because it redoes less work.
Want this built for you?
We write these memos because we build this stuff every day. If you want it working in your business instead of sitting on your reading list, that is literally our job.