Best Free Terminal AI Coding Agents in 2026 (Gemini CLI Alternatives)

For a year, the easiest answer to "what's a free AI coding agent I can run in my terminal?" was Gemini CLI — 1,000 requests a day on a personal Google account, no credit card. That answer expires on June 18, 2026, when Google retires the free Gemini CLI for individual users in favor of the Antigravity CLI, whose free tier is a fraction of the size.

So the field is reshuffling. This list ranks the terminal AI coding agents that are actually free to run for a beginner with no budget — with one honest lens: does it cost you money or hit a wall once you start using it?

The Honest Definition of "Free"

Every tool here is free to install. That's not the question. The question is what happens when you run a task:

• Genuinely free: open-source agents running a local model (via Ollama). The model runs on your machine, so there's no per-request cost and no quota — your only cost is a capable computer and some setup.
• Free with a wall: a hosted free quota (like Antigravity CLI's ~20 requests/day). Fine for light use, but you'll hit the ceiling.
• Not free to run: anything calling a paid cloud API (Claude Code, Codex CLI) — the software is free, the model isn't.

The list is ordered by that lens: truly-free first.

1. Goose — The Genuinely Free Winner

Goose is Block's open-source terminal agent (now stewarded by the Agentic AI Foundation under the Linux Foundation). It's model-agnostic: point it at a local Ollama model and it costs $0 per request, forever, or plug in any API key when you want a stronger cloud model.

That flexibility is exactly what the Gemini CLI retirement should teach you to want — you're not tied to one vendor's free tier that can be cut. The trade-off is the usual local-model one: a small local model is less capable than a frontier cloud model, and you need the RAM (and ideally a GPU) to run it well.

Best for: anyone with a capable machine who wants a real, no-strings free terminal agent.

2. Aider — Git-Native, Bring Your Own Model

Aider is the terminal pair-programming pioneer, and its signature is that it thinks in git: every edit it makes is a commit, so you always have a clean undo. It's open-source and model-agnostic — run it on a local Ollama model for $0, or connect a cloud API key (you pay the provider directly, often just cents per session).

For a beginner, the git-as-safety-net design is genuinely reassuring: you can let it work and roll back any change cleanly.

Best for: people who want provider flexibility and a built-in safety net, and don't mind a terminal-first workflow.

3. OpenCode — The Most-Starred Open-Source Agent

OpenCode is an MIT-licensed terminal agent that has become the most-starred open-source coding agent on GitHub, on the strength of its provider breadth — it works with effectively any model backend. Like the others here, "free" means running a local model; with a cloud key you pay the provider.

It's a strong, actively maintained choice if you want the broadest model support and a large community behind the tool.

Best for: developers who want maximum model/provider flexibility from an open-source agent.

4. Cline — Open-Source, Also Lives in Your Editor

Cline is best known as a VS Code/JetBrains extension, but it also ships a CLI. It's open-source and BYOK, with explicit per-change approval — it shows you each edit before applying it, which is a good default for beginners. Run it on a local model for $0 or connect an API key.

It's the natural pick if you want the same open-source agent in your editor and your terminal.

Best for: beginners who want to see and approve every change, in the editor or the terminal.

5. Antigravity CLI — The Official Gemini CLI Successor (Thin Free Tier)

Antigravity CLI (agy) is what Google is moving Gemini CLI users to. It's the official path, it's backed by Gemini 3 models, and it has a free tier — but a thin one: around 20 agent requests per day, cut from 250 at its late-2025 launch. It's also closed-source, and its credit system (paid usage at $0.01/credit) is not transparently documented.

For genuinely light use it's serviceable and it's the least-friction migration if you're already in Google's ecosystem. But it doesn't win a "free" ranking, because the free tier is small and has already been cut repeatedly.

Best for: existing Gemini/Google users who want the official successor and only need a handful of agent runs a day.

6. Codex CLI — Free to Install, Paid to Run

Codex CLI is OpenAI's open-source terminal agent, with sandboxed command execution by default (a nice safety feature). But there's no meaningful free quota: it runs through a ChatGPT plan or a paid OpenAI API key, billed per token. The software is free; the model is not.

Best for: people already paying for ChatGPT or OpenAI API access who want a fast, sandboxed terminal agent.

7. Claude Code — Not Free, But the Quality Bar

Claude Code isn't a free option — it needs a Claude Pro plan ($20/month) or pay-per-token API credits after a small trial. It's on this list only as the honest "if you're willing to pay" answer: for complex, multi-file work it's the most capable terminal agent here. If your budget is truly $0, it's not your tool yet.

Best for: anyone ready to pay $20/month for the strongest model quality and workflow.

The Bottom Line

Now that Gemini CLI's free tier is going away, the genuinely-free crown passes to open-source agents running a local model — Goose first, then Aider, OpenCode, and Cline. They cost nothing per request and, just as importantly, they're not tied to a vendor's free tier that can be cut from under you.

• Truly free, have a capable machine: Goose with a local model.
• Truly free, want a safety net: Aider (git-native).
• Official Gemini successor, light use only: Antigravity CLI (~20 requests/day).
• Willing to pay for the best: Claude Code.

For the broader landscape beyond the terminal — IDEs, app builders, and more — see our best free AI coding tools in 2026 roundup. And if you're migrating off Gemini CLI specifically, the Gemini CLI retirement guide walks through the move.