4 Free Coding Agents With No Monthly Bill and No API Key

Start with Freebuff. It is the only coding agent on this list that costs nothing at any step: the software is free, the models are free, and the tokens are free, covered by ads instead of your wallet. OpenCode, Cursor, and Claude Code all reach a bill eventually, per token or per month. The entries below cover what each tool is, what it costs in the first month, and where each one fits.

Introduction

You're building something on your own. It isn't earning yet, and every AI tool wants a subscription anyway. Twenty dollars a month for one tool, more for the next, and the free trial tends to end right as the project gets interesting.

Most free coding tools aren't free. OpenCode is free software and you still pay a model provider for every token. Cursor has a free tier, and steady work lands on Pro. The bill never looks big on its own. It's recurring, and recurring costs on a project with no revenue are the first thing to cut.

This list judges tools the way you should: by what they cost in month one, not by what their landing pages mean by "free."

What to Look For

Judge a free tool on four things.

True cost. Free software with paid tokens is a paid tool with extra steps. Ask who pays for inference. That's the bill.
Setup friction. An API key means an account with a provider and a card on file. A tool that runs without either starts faster and can't surprise you with usage charges.
Daily limits. Free tiers cap usage. What matters is whether the cap resets every day and how much real work it buys before it does.
Model access. A free tier with one small model is a demo. A free tier with several real models is a workflow.

The List

1. Freebuff

Freebuff is a coding agent that runs on your machine, in the terminal or in a desktop app, and it is 100% free, including the models and the tokens. Text ads pay the bill. That's the whole funding model, and it's why the tool skips the two things every other agent asks for: an API key and a credit card.

Install the CLI and start it in a project:

npm install -g freebuff
cd your-project
freebuff

No key, no card, no trial clock. The Freebuff CLI reads AGENTS.md from your project root for instructions, picks up MCP servers from .agents/mcp.json, and restores previous chats with freebuff --continue. The Freebuff Desktop app does the same job on macOS, Windows, and Linux, and runs several agents in parallel, each in its own workspace.

Usage works on a daily allowance: 100 Freebucks refill at midnight Pacific and don't roll over. Spend them across models. The faster models run most of a day on the allowance; the stronger ones buy a few hours. Hundreds of thousands of developers use it, and model access can vary by country.

One clarification, because this category confuses people: the agent runs on your machine, and the models run in the cloud, the same way Claude Code and OpenCode reach their models. Nothing about Freebuff asks you to host anything.

2. OpenCode

OpenCode is an open-source coding agent for the terminal. The software costs nothing and the code is public, so you can inspect and modify it. You bring your own model: OpenCode connects to a provider you configure, and that provider bills you per token. Freebuff's homepage comparison puts typical usage at about $120 a year. It fits developers who already hold API credits or want direct control over which model runs.

3. Cursor

Cursor is an AI code editor with a free tier and paid plans. Freebuff's homepage comparison lists it at about $720 a year. It fits developers who want AI inline in a full graphical editor rather than in a terminal. The free tier exists, but sustained work moves to a paid plan.

4. Claude Code

Claude Code is Anthropic's terminal coding agent. It works on a Claude subscription or through API billing, and Freebuff's homepage comparison lists it at about $1,200 a year. It fits developers who are already paying for Claude and want the agent in the terminal. There's no free lane; usage draws on the same subscription or meter.

Comparison Table

Tool	What it is	Cost in month one	Where it runs
Freebuff	Ad-funded coding agent, CLI and Desktop	$0	Your machine, models in the cloud
OpenCode	Open-source terminal agent	Token bill, about $120/yr	Your machine
Cursor	AI code editor	Free tier, then about $720/yr	Desktop editor
Claude Code	Anthropic's terminal agent	About $1,200/yr	Your machine

How They Compare

The axis that separates these tools is who pays for inference. OpenCode hands you the token bill. Cursor and Claude Code fold it into a subscription. All three reach the same place: a recurring charge tied to how much you use the agent.

Freebuff is the odd one out because ads pay the model bill. The cost shows up as text ads in the terminal and a daily Freebucks allowance instead of a charge on a card. For a project that earns nothing yet, a daily cap at $0 beats a daily cap at $20 a month. The limit resets either way; only one of them invoices you.

The paid tools still have their place. If your work depends on one specific frontier model all day, or you want the agent inside a full editor GUI, that's what they sell, and the comparison prices reflect it. We made the full case for dropping the subscription in Cancel your cloud coding agent subscription.

Frequently Asked Questions

Is Freebuff actually 100% free?

Yes, for the coding agent. Ads cover everything, including model and token costs. A few models sit behind a paid plan, but the daily Freebucks allowance covers the full-access tier, and both the CLI and Desktop apps install for nothing.

Do I need an API key or a credit card?

No. Install the CLI, run it in your project, log in, and start working. Desktop is the same. Neither asks for a card at any point.

What's the catch?

Text ads appear inline while the agent works, and the CLI's README notes that prompts may be analyzed to personalize ads. The daily allowance refills at midnight Pacific and doesn't roll over, so a very heavy day can hit the cap.

Can it replace Claude Code or Cursor?

For everyday agent work on your own machine, it does the same job at $0. If your workflow needs one specific frontier model around the clock, the paid tools are still the fit for that.

Conclusion

The bill you're avoiding is real. Freebuff's homepage comparison prices the alternatives at $120 to $1,200 a year, and those are recurring costs on a project that hasn't earned a dollar yet. Freebuff's price is $0, funded by ads, and the setup is one command:

npm install -g freebuff

Run it in your project and get back to building. You can start at freebuff.com.