"Free" AI coding tools where you bring your own key: what you actually pay for

oes. If you put them in a "free tools" list with no explanation, someone installs one, plugs in an Anthropic or OpenAI key, and gets a bill a week later. So here's how I record them, and what each one actually charges, checked against the official pages today (Nov 3, 2026). We count these as having a free tier, because the software itself costs nothing.

But each one carries a note that says where the money goes: your own API key, a hosted credit plan, or a free model the vendor provides. "Free" without that note is misleading. Zed (open-source editor) Personal plan is $0 forever, with unlimited use when you bring your own API keys or external agents like Claude Agent or Codex CLI. The pricing page lists supported key providers including Anthropic, OpenAI, Google AI, DeepSeek, Mistral, OpenRouter, Amazon Bedrock, and local runners like Ollama and LM Studio.

Pro is $10/month with $5 of tokens included, then billed at API list price +10%. There's a 14-day Pro trial, no card required. Cline (open-source VS Code extension and CLI) The open source version is free for individual developers, with no subscriptions or seat fees. You pay only for inference: either bring your own keys or buy credits through the Cline provider, which their pricing page describes as "at cost".

Enterprise adds things like SSO and the JetBrains extension. Aider (open-source terminal pair programmer) The tool is free. You pay your LLM provider directly; the quick-start literally passes --api-key on the command line. It can connect to local models too, which is the only way here to get the model cost to zero on your own hardware.

OpenCode (open-source agent, MIT license) This one is the exception that comes closest to truly free: it ships with a set of free models you can use without creating an account. The FAQ notes your data is stored when you use those free models, so that's the trade-off. You can also log in with an existing ChatGPT Plus/Pro or GitHub Copilot subscription, or connect other providers, which may cost extra. Warp (terminal with built-in agents, not open source) The core terminal is free on macOS, Windows and Linux.

On the free plan, agent usage beyond what's included is pay-as-you-go, or you bring your own AI inference. The paid Build plan includes $20 of agent usage a month at API rates. If your goal is "spend $0", the honest options are: OpenCode's free models (with the data trade-off), or any of these tools pointed at a local model. Everything else on this list is free software sitting in front of a metered API.

If you already pay for a ChatGPT or Copilot plan, OpenCode and Zed can reuse what you have instead of adding another bill. And if you just want a predictable monthly number, the bring-your-own-key route is usually the wrong one. A flat plan with included usage is easier to budget, even if it's not the cheapest per token. The directory currently has 244 tools, 176 marked with a free tier, 31 open source.

Prices change often, so each tool page links to the official pricing page it was checked against. The full free list is here, and how we check listings is on the review standards page.