AI Creative OS
01Install the editor Cursor is built on02Add the agent, not an autocomplete03Give it a brain that costs nothing04Write the rules file before the first task05Start with a real task, not a toy

Build Your Own AI Coder

Cursor Pro is twenty dollars a month. The editor underneath it is free and open source, the agent that does the actual work is free and open source, and the model has a free tier. Here is the whole stack, installed in about fifteen minutes, plus the rules file that makes it behave like a senior dev instead of an autocomplete.
Build it step by stepInteractive · ~4 min · with Z’s build guideStart →
01Step 1
Install the editor Cursor is built on
Go to code.visualstudio.com and install VS Code. Its own homepage calls it "the open source AI code editor", and Cursor is a fork of it. So the editor was never the part you were paying for. Free, MIT licensed, every platform. If you already have it, skip to step 2.
02Step 2
Add the agent, not an autocomplete
In VS Code hit Extensions and search Cline. Install it. This is the piece that matters: it reads your files, runs terminal commands, uses the browser and works through a whole task, asking permission at each step. 67,700 stars, Apache 2.0, 5,250,282 installs, and free at every usage level. Anything that only suggests the next line is a different category of tool.
03Step 3
Give it a brain that costs nothing
Open aistudio.google.com, sign in, click Get API key, create one. Google's own pricing page lists a Free tier with free input and output tokens on Gemini 3.8 Flash. In Cline, open settings, pick Google Gemini as the provider, paste the key, select the Flash model. That is the last step. You now have an agentic coder for nothing.
04Step 4
Write the rules file before the first task
This is the step everyone skips and it is the one that decides whether the thing is useful. Make a file called .clinerules in your project root. The agent reads it on every single task, so your standards stop being something you re-explain in each chat. The block below is a working starting point, copy it as is and edit two lines.
05Step 5
Start with a real task, not a toy
Do not ask it to build a to-do app. Point it at something that actually annoys you: "read every file in this folder, tell me what it does, and write a README". Watch it plan, approve each step, and stop it the moment it goes somewhere you did not intend. Two or three real tasks and you will know exactly where the free tier ends and whether you ever needed the subscription. If you outgrow the free limits, keep the same setup and swap the key, because the editor and the agent stay free either way.
The rules file · save as .clinerules in your project root
# HOW YOU WORK
# Plan first. List the files you will touch and wait for my yes.
# One task at a time. Do not refactor things I did not ask about.
# Read the file before you edit it. Never guess at contents.

# THIS PROJECT
# Stack: <your language / framework here>
# Run tests with: <your test command here>
# Match the style of the file you are in. No new dependencies without asking.

# HARD RULES
# Never run a destructive command (rm, drop, force push) without asking.
# Never commit or push unless I say so.
# Never put secrets or API keys in a file you create.
# If you are unsure, stop and ask. A question is cheaper than a rewrite.
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