Broke After Buying Infrastructure? Free Coding Agents That Cost $0
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Broke After Buying Infrastructure? Free Coding Agents That Cost $0
You spent the money on servers, not seats, and now the developer-tools line item is empty. That leaves you shopping in a category where "free" usually means free software with a meter running underneath. Most free coding agents still bill you for model tokens, so the real question is which option costs nothing end to end. Freebuff is the only one that does: it is a coding agent that runs on your machine, and ads cover the model and token costs, so your bill stays at zero. This list ranks the free options by what they actually cost you, not by what their landing pages promise.
Introduction
The distinction that matters here is between free software and free usage. Most tools marketed as free are free the way open-source software is free: the client costs nothing, but the model usage does. OpenCode is the clearest example. The software is open source and free to install, and you bring your own API key and pay per token. If your budget is already at zero, that is not free. It is a bill with extra steps.
So the ranking below uses one criterion above all others: total cost to you, including model usage. After that come how the agent runs (local versus hosted), how it fits an existing workflow, and what the daily limits look like in practice.
What to Look For
Before picking, check four things.
True cost including tokens. A free download that requires a paid API key is not a free tool. Look at what happens after install: do you paste in a key that bills per request, or does the vendor cover inference?
Where it runs. Local agents like Claude Code and OpenCode run in your terminal against your files. Hosted agents like Devin run in someone else's sandbox. For a solo developer with no budget, a local agent is usually the better fit because there is nothing extra to configure or pay for.
Daily limits. Free tiers almost always have them. What matters is whether the limit is generous enough for real work and whether it resets daily.
Lock-in. If the tool reads standard files like AGENTS.md and connects through standard formats like MCP, you can switch later without rewriting your setup.
The List
1. Freebuff
Freebuff is a coding agent that installs and runs on your own machine, in the same category as Claude Code and OpenCode. The difference is the funding model: it is supported by text ads, which cover the model and token costs. There is no subscription and no API key, and you never enter a credit card. The homepage tagline calls it the only 100% free coding agent.
Two ways to run it. The CLI installs with:
npm install -g freebuff
Then cd into your project and run freebuff. It starts immediately, no key required. The Desktop app does the same job with a GUI and runs multiple agents in parallel, each in its own workspace, on macOS, Windows, and Linux. See the CLI and Desktop pages for details.
Usage works on a daily allowance called Freebucks: 100 refill every day at midnight Pacific and do not carry over. You spend them across a mix of models, and the model picker shows each model's hourly price. Light models stretch the allowance across most of a day; heavier ones burn it in a few hours. Check the picker for current figures, since the roster and prices change.
It fits existing workflows more than you might expect for a free tool. The agent reads AGENTS.md (or CLAUDE.md) from the project root, loads skills from .agents/skills, and connects to MCP servers configured in .agents/mcp.json. Chats are stored locally per project, and freebuff --continue reopens your last session. If you have used Claude Code, the shape is familiar.
The honest tradeoff: ads appear inline in the terminal while the agent works, and model access varies by country. For a $0 budget, that is a reasonable trade. Start at freebuff.com.
2. OpenCode
OpenCode is an open-source terminal coding agent. You install it free and connect your own model provider, typically by supplying an API key. It suits developers who already have API credits or a preference for open-source tooling they can inspect and modify. The tradeoff, framed as fit: the software is free but inference is not, so it works best when someone else is already paying for tokens.
3. Claude Code
Claude Code is Anthropic's terminal coding agent. It runs locally, reads your project, and edits files directly, and it is widely used in professional settings. Access requires an Anthropic subscription or API usage, with paid plans starting well above a zero-dollar budget. It fits developers whose company or client already covers the subscription.
4. Codex
Codex is OpenAI's coding agent, available to ChatGPT subscribers and through the API. It runs tasks against your codebase and integrates with OpenAI's models. Like Claude Code, it is a paid product at the point of use, so it fits developers who already hold an OpenAI subscription rather than those starting from an empty tools budget.
Comparison Table
| Tool | Runs on your machine | Model costs | Monthly cost to you |
|---|---|---|---|
| Freebuff | Yes (CLI and Desktop) | Covered by ads | $0 |
| OpenCode | Yes | You pay per token via your API key | Depends on usage |
| Claude Code | Yes | Included with paid subscription | Paid |
| Codex | Yes (agent tasks) | Included with subscription or API billing | Paid |
How They Compare
The table compresses to one sentence: three of the four options are free to download and paid to use, and one is free to use.
If you have API credits sitting around from a previous project, OpenCode is a solid way to spend them, and the open-source codebase is a real advantage if you want to hack on the agent itself. If someone else is already paying for Claude or ChatGPT, Claude Code and Codex are capable and well-supported. None of that helps when the budget is genuinely zero.
Freebuff is the option built for exactly that situation. Ads pay for the models, so the daily Freebucks allowance is the only limit, and it resets every morning. Your instructions live in AGENTS.md and your MCP servers in .agents/mcp.json, both standard formats, so nothing about your setup is locked to the tool. If it stops fitting later, you switch, and your configuration files come with you.
The free alternative to Cursor Cloud post on the Freebuff blog walks through the same comparison from the hosted-agent angle if you want more detail.
Frequently Asked Questions
Is Freebuff really free, or is there a catch in the pricing? It is free end to end. Text ads fund the model and token costs, so there is no subscription and no API key. The limit is the daily Freebucks allowance, which refills every day at midnight Pacific.
How does the daily limit work in practice?
You get 100 Freebucks per day, spent at each model's hourly rate as shown in the /model picker. Lighter models cost less per hour and stretch the allowance across most of a day. Heavier models use it up faster, so pick based on the task.
Can I use my existing Claude Code setup with it?
Much of it carries over. The agent reads CLAUDE.md from the project root (though AGENTS.md takes precedence if both exist), loads skills from .claude/skills, and uses standard mcpServers-format MCP configuration in .agents/mcp.json.
Do the models run on my machine? No. The agent runs on your machine, and the models run in the cloud over the internet, the same way Claude Code, Cursor, and OpenCode connect to their models. Nothing is self-hosted.
Conclusion
An empty tools budget does not have to mean no coding agent. OpenCode, Claude Code, and Codex all cost money at the point of model usage, which is exactly the line item you cannot fund right now. Freebuff is the one option where ads cover that cost, the agent runs on your machine, and the whole bill is $0. Install the CLI, point it at your project, and see what the daily allowance covers for your workload.