Antigravity CLI: Free Access to Top Gemini and Claude Models in the Terminal

What Is Antigravity CLI

As AI coding tools continue to multiply, most developers have grown accustomed to paying for API keys and monthly subscriptions. But a demo video recently circulating on YouTube proposes another approach: through a CLI tool called Antigravity (command agy), developers can call top models like Gemini 3.1 Flash and Claude Sonnet directly in the terminal, and it claims to be completely free. The video is presented as an animated conversation—lighthearted in form, but the tool's shape and workflow are worth breaking down.

According to the video description, Antigravity is a command-line tool that runs in the VS Code terminal. Users simply open the terminal, paste an install command, and deployment completes within seconds. After installation, typing agy and pressing Enter opens a full AI interaction interface.

This interface supports switching between Gemini 3.1 Flash, Claude Sonnet, and GPT-series models. The video emphasizes that the entire process requires no jumping to browser tabs, and no separate application or payment for API keys. For developers used to doing everything inside their editor, this "ask directly in the terminal, generate code on the spot" workflow can indeed reduce the cost of context switching.

CLI (Command-Line Interface) is a user interface that interacts with programs through text commands, as opposed to a graphical user interface (GUI). Common developer tools like git, npm, and docker are typical CLI tools. CLI tools offer advantages in scriptability, composability, low resource usage, and the ability to retain input/output history directly in the terminal session. The agy mentioned here is the executable command that Antigravity registers to the system path; entering it launches an interactive session (REPL-style interface) that continuously receives user questions and streams model output, rather than executing once and exiting.

Questions Behind "Free" and the Video's Ambiguities

The most eye-catching statement in the video is "completely free." But this needs to be viewed objectively: the video does not show any official pricing page, terms of service, or authorization documentation from the model providers. Whether "free" means shared quotas provided by the tool's author, some kind of proxy forwarding mechanism, or a limited-time promotional strategy—the video gives no answer.

Another notable detail is that the video ends by directing viewers to comment "setup" to obtain the installation guide, rather than publishing the command directly. This lead-generation approach is common on short-video platforms, but it also means viewers cannot independently verify the tool's safety and stability before actually using it. For developers who need to handle private code, handing terminal permissions to a CLI tool of unknown origin itself requires careful evaluation.

API keys and proxy forwarding are key to understanding the "free" controversy. Major model vendors (Google, Anthropic, OpenAI) all charge by token, and calls must carry an API Key for identity and quota verification. If a third-party CLI claims to call these models without users providing their own keys, this usually implies two possibilities: first, the tool's author provides shared keys or a quota pool at their own expense, with user requests relayed through their servers (i.e., proxy forwarding)—in which case users' prompts and code pass through third-party servers; second, the tool has no real model calls at all and is merely a demo or lead-generation scheme. Under the proxy forwarding model, data flows, log retention, and abuse risks are all controlled by the intermediary—which is exactly what needs careful assessment when handling private code.

The Experience Value of Calling Models in the Terminal

Setting aside the free-or-not debate, the interaction form Antigravity represents has its merits. In traditional workflows, developers need to switch back and forth between the IDE, browser, and API documentation; CLI tools compress model invocation into a single command, keeping prompts and generated results within the terminal session.

The scenario demonstrated in the video is: asking the model questions directly during coding, with the model generating the needed content instantly. This mode suits quickly validating ideas, generating boilerplate code, or explaining error messages. For developers already deeply comfortable with the terminal, the learning curve is nearly zero.

A Few Things to Verify Before Use

If you're interested in this tool, it's advisable to confirm the following before installing: whether the tool's code repository and maintainer information are public; whether model calls are relayed through third-party servers, and where code data is sent; whether the free quota has call-count or frequency limits; and whether there are terms allowing session content to be used for other purposes.

The video closes with the slogan "stop wasting money," which is emotionally compelling, but tool selection ultimately comes back to verifiable facts. Whether Antigravity can reliably provide these models long-term, and how long the free model can last, currently has no public information to support it. Treating it as a terminal AI interaction experiment worth observing is more prudent than treating it as a guaranteed money-saving solution.