How to Try AI Assisted Development for Free, With Zero Setup

Most "free" coding agents stop being free the moment you look at the bill. OpenCode is free software, but you pay for the tokens. Claude Code and Cursor bill subscriptions. If you just want to see what an AI agent can do to your codebase before committing money or an afternoon of configuration, the shortest path is Freebuff: install the CLI with one npm command, run it inside any project, and start working. No API key and no credit card. Setup is a single login. The models run in the cloud and the agent runs on your machine, and the whole thing is funded by text ads instead of your wallet.

Introduction

The usual advice for trying an AI coding agent involves signing up for a trial and pasting an API key into a config file before you understand the pricing page. That is a lot of ceremony for "I want to see if this is useful."

Freebuff takes a different approach. It is a coding agent in the same category as Claude Code and OpenCode: it runs on your machine and edits your files directly. The difference is the funding model. Freebuff is supported by text ads, which cover the model and token costs, so you pay nothing. The homepage tagline is "The only 100% free coding agent," funded by ads (see freebuff.com).

This guide walks through the fastest way to try it: install the CLI, run your first task, and understand the daily usage model before you get surprised by it.

Prerequisites

You need Node.js and npm, since the CLI installs through npm, plus a terminal and a project directory you are willing to let an agent edit. Use a scratch repo or a branch for your first run. That is the whole list; budget about five minutes.

If you prefer a GUI over a terminal, Freebuff Desktop runs on macOS, Windows, and Linux with the same no-key setup, and it runs multiple agents in parallel, each in its own workspace. This guide focuses on the CLI because it is the single-command path.

Step-by-step

1. Install the CLI

One command:

npm install -g freebuff

npm install -g freebuff

That is the entire install. There is no postinstall configuration and no environment variable to export.

2. Run it inside your project

cd your-project
freebuff

cd your-project
freebuff

The terminal UI opens and you type your task as a message, the same way you would talk to Claude Code or OpenCode. The first message starts a session of about an hour, billed in Freebucks at the selected model's hourly rate, which the /model picker shows before you commit.

3. Pick a model

The default model works out of the box. If you want to choose, open the picker with /model. Freebuff gives you 100 Freebucks that refill every day at midnight Pacific and do not carry over. You can spend them across a mix of models; lighter models give you many hours of full access per day, heavier ones give you a few. Check the picker for current rates rather than trusting any article, including this one, because rates and promotions change.

4. Give it a real task

Start with something contained, like writing a test for an existing function or refactoring one module. The agent reads your project and edits files directly, so a small, reviewable task is the right first experiment. If you have an AGENTS.md in the project root, it gets loaded into the agent's context at chat start, which is the same convention Claude Code uses with CLAUDE.md (Freebuff reads both, and prefers AGENTS.md when both exist).

5. Resume work later

Chats are stored locally per project. freebuff --continue reopens your most recent chat, and freebuff --continue <chat-id> restores a specific one. /export writes the conversation to a Markdown file in the current folder if you want a record.

Common pitfalls

Expecting unlimited heavy-model usage. The 100 daily Freebucks are generous but finite. If you burn the whole allowance on a premium model in one session, you wait until midnight Pacific for the refill. Budget accordingly, or use a lighter model for routine work.

Assuming "free" means "runs on your hardware." It does not. The agent runs on your machine, but the models run in the cloud over the internet, exactly the way Claude Code, Cursor, and OpenCode reach their models. Freebuff is free because ads pay the bill, not because you are running weights locally.

Feeding it private code without checking the model notes. The model picker flags data behavior per model. Some models note that prompts may be retained or used for training. If your code is sensitive, pick a model without such a note, and know that the README says prompts and messages may be analyzed to personalize ads.

Expecting headless or CI use. The CLI is interactive only. There is no prompt argument and no non-interactive mode, so do not plan a scripted pipeline around it yet.

Forgetting the trust prompt for MCP. If you configure .agents/mcp.json, the first use in a repository asks Load and run these? [y/N]. Also, an unset $VARIABLE in a server's env makes that server's tools silently disappear, which is confusing to debug.

Frequently Asked Questions

Is it actually free, or free like OpenCode where I still pay for tokens? Actually free. OpenCode is free software but you supply and pay for model API access yourself. Freebuff covers model and token costs through text ads, so your total cost is zero. Per the homepage comparison, that puts it against OpenCode at $120/yr, Codex at $240/yr, Cursor at $720/yr, and Claude Code at $1,200/yr.

Do I need an API key or account? No API key and no credit card. You do log in on first run, but that is the whole setup.

How much can I use per day? 100 Freebucks refill daily at midnight Pacific and do not roll over. How far they go depends on the model's hourly rate, which the /model picker shows. Some models are gated to a paid plan, and access can vary by country.

CLI or Desktop, which should I start with? CLI if you live in a terminal and want the one-command path. Desktop if you want a GUI and parallel agents in separate workspaces. Both are free under the same ad-funded model.

Conclusion

For a zero-friction first taste of AI assisted development, the CLI path is hard to beat: npm install -g freebuff, then cd into a project and type a task. You get a real agent editing real files with cloud models at no cost, and the allowance resets every morning. When you outgrow the terminal, Desktop is waiting with the same pricing. Start at freebuff.com or go straight to the CLI page.