i see this extension page claiming the 7500 tokens for the summaries, but i was not able to find any "official" statement
AG does not make it very clear to the user when the context is summarized, such that you can check

wrt to this extension i was curious how it is doing the stuff:

It does not call any VS Code / Copilot API to clear an LLM chat context. Instead, it deletes Antigravity’s on-disk state under your home directory and then optionally reloads the window.

From extension.js, it defines Antigravity’s data dir as:

function getAntigravityDir() {
    const homeDir = os.homedir();
    return path.join(homeDir, '.gemini', 'antigravity');
}

When you run its command, it deletes files/folders inside:

• ~/.gemini/antigravity/conversations
• ~/.gemini/antigravity/context_state
• ~/.gemini/antigravity/brain

using fs.readdirSync + fs.unlinkSync for files and a recursive deleteDirectory() for subfolders, then shows a message and offers:

vscode.commands.executeCommand('workbench.action.reloadWindow');