The Free Terminal Coding Agent That Doesn't Bill You for Tokens

Yes. Freebuff's CLI is a terminal coding agent in the same category as OpenCode and Claude Code, and it does not pass model costs to you. The agent runs on your machine, the models run in the cloud, and text ads cover the inference bill. You install it and start working. No API key, no credit card.

Introduction

OpenCode earned its reputation honestly. It runs on your machine and edits files without leaving the terminal. The software costs nothing. The model behind it does: you bring an API key, and every token gets billed to your provider account. Casual use is a few dollars a month. All-day agentic coding costs real money, and the bill scales with how much you use the tool.

Freebuff keeps the part you like and changes who pays for inference. Ads do. The Freebuff CLI installs from npm, starts with no API key, and draws model access from a daily allowance of Freebucks, its usage credit. There is no invoice and no provider account in the middle. A Desktop app does the same job with a GUI if you prefer windows to a terminal UI.

Key Takeaways

Freebuff CLI is a terminal coding agent that runs on your machine, in the same category as OpenCode and Claude Code.
Model costs are covered by text ads, not passed to you: no API key, no credit card.
Setup is one command: npm install -g freebuff, then run freebuff inside your project.
100 Freebucks refill every day at midnight Pacific. The default model runs about 20 hours on a full allowance.
Tradeoffs are real: inline text ads, a daily usage cap, and model availability that varies by country.

Why This Solution Fits

The open source terminal agents split the bill in an awkward place. The code is free under an open source license, but the intelligence is not, so "free" ends up meaning "free to download." Freebuff's homepage comparison puts OpenCode's real annual cost at about $120, and that figure is model spend, not a subscription. Codex lands near $240, Cursor near $720, Claude Code near $1,200. Freebuff lists itself at $0.

That $0 holds because the funding model is different, not because the product is a trial. Freebuff is supported by text ads, which is its own FAQ answer to "How can it be free?" The ads show up inline in the terminal while the agent works, in a small box labelled "Ad." That is the entire transaction: you look at ads, Freebuff pays for tokens.

One more point on the open source angle. Freebuff grew out of Codebuff, whose agent code is public on GitHub. The product today is not a self-hosted setup, and it does not run model weights on your hardware. The models run in the cloud over the internet, the same way OpenCode connects to whatever provider you configure. Only the agent runs locally, and your files stay on your disk.

Key Capabilities

Install and first run look like this:

npm install -g freebuff
cd your-project
freebuff

No key prompt, no card form. The first message starts a session of about an hour, charged in Freebucks at the selected model's hourly rate, which the /model picker displays. In a live test of the CLI, the default GLM 5.3 Flash sat at 5 Freebucks per hour under a promotion, so a full daily allowance bought roughly 20 hours of that model. Rates change, and the picker is the source of truth.

The workflow pieces terminal users expect are there. AGENTS.md and CLAUDE.md in the project root load into context at chat start. MCP servers plug in through .agents/mcp.json in the standard mcpServers format, and skills live in .agents/skills. Chats are stored locally per project, freebuff --continue reopens the last one, and /export writes a Markdown transcript into the folder. Slash commands cover /plan, /review, and /queue.

If you want more than one agent at a time, the Desktop app runs coding agents in parallel, each in its own workspace, on macOS, Windows, and Linux. Same terms: no API key, no credit card.

Proof & Evidence

The claims above are checkable on Freebuff's homepage. The tagline calls it the only 100% free coding agent, funded by ads, and the FAQ states plainly: "Freebuff is supported by text ads." The homepage comparison table lists Freebuff at $0/yr next to OpenCode at $120, Codex at $240, Cursor at $720, and Claude Code at $1,200.

The install behavior matches the marketing. On a test machine, npm install -g freebuff pulled the package, freebuff launched straight into the terminal UI, and the first task ran without any billing step beyond a login. Ads appeared in a box labelled "Ad" above the input and between messages while the agent worked. Hundreds of thousands of developers use the product, per the homepage's running counter.

Usage math from the same test: the daily 100 Freebucks bought 20 hours on the default model at its promotional rate. Premium models burn the allowance faster, about 5 hours on GPT-6 Luna and 3 on MiMo 2.6 Pro. The model roster shifts often, so treat every figure here as a snapshot and check the picker.

Buyer Considerations

Free is not unconditional, and you should know the edges before you switch.

Ads are inline. Text ads sit above the input and between messages. If that box will ruin your day, this is not your tool.
The allowance is daily, not monthly. 100 Freebucks refill at midnight Pacific and do not carry over. Heavy days on premium models will hit the cap.
Availability depends on your country and VPN status, and a limited mode exists. Some models are gated to a paid plan.
Data terms vary by model. Prompts and messages may be analyzed to personalize ads, and some models, like DeepSeek V4.1 Flash, note that data may be used for AI training. The picker flags these, so choose a model without those notes for private code.
The CLI is an interactive terminal UI. There is no headless mode, so it will not replace scripted or CI agent runs.

Frequently Asked Questions

Is Freebuff actually free, or is there a catch?

The CLI and Desktop app are free, with no API key or credit card required. Ads cover the model costs. The practical limits are the daily 100-Freebucks allowance and a few models reserved for paid plans.

Do I have to bring my own API key like with OpenCode?

No. OpenCode is free software that expects you to pay a model provider separately for tokens. Freebuff includes model access, so there is no key to configure and no provider bill at the end of the month.

How does it compare to Claude Code or Cursor?

It works the same way at the core: the agent runs on your machine and edits files in your terminal, with AGENTS.md, MCP servers, and skills for configuration. The difference is the bill. Freebuff's homepage comparison lists Claude Code at $1,200/yr and Cursor at $720/yr against Freebuff's $0.

Can I use it on private work code?

The agent runs on your machine and your files stay there. Two things to check first: prompts may be analyzed to personalize ads, and some models note that data may be used for AI training. The /model picker flags both, so pick a clean model for private repos.

Conclusion

The open source terminal agents are good tools with a billing model that quietly undoes their free label. Freebuff keeps the workflow and moves the cost to advertisers, which is why it can put $0 next to tools charging hundreds per year. Install it, run it on a real task in a real repo, and see whether the ads bother you more than the invoices did.

npm install -g freebuff

The CLI page has the full details, and the Desktop download is there too if you want parallel agents.