import { createServer } from "node:http"; import { ANTIGRAVITY_REDIRECT_URI } from "../constants"; interface OAuthListenerOptions { /** * How long to wait for the OAuth redirect before timing out (in milliseconds). */ timeoutMs?: number; } export interface OAuthListener { /** * Resolves with the callback URL once Google redirects back to the local server. */ waitForCallback(): Promise; /** * Cleanly stop listening for callbacks. */ close(): Promise; } const redirectUri = new URL(ANTIGRAVITY_REDIRECT_URI); const callbackPath = redirectUri.pathname || "/"; /** * Starts a lightweight HTTP server that listens for the Antigravity OAuth redirect * and resolves with the captured callback URL. */ export async function startOAuthListener( { timeoutMs = 5 * 60 * 1000 }: OAuthListenerOptions = {}, ): Promise { const port = redirectUri.port ? Number.parseInt(redirectUri.port, 10) : redirectUri.protocol === "https:" ? 443 : 80; const origin = `${redirectUri.protocol}//${redirectUri.host}`; let settled = false; let resolveCallback: (url: URL) => void; let rejectCallback: (error: Error) => void; const callbackPromise = new Promise((resolve, reject) => { resolveCallback = (url: URL) => { if (settled) return; settled = true; if (timeoutHandle) clearTimeout(timeoutHandle); resolve(url); }; rejectCallback = (error: Error) => { if (settled) return; settled = true; if (timeoutHandle) clearTimeout(timeoutHandle); reject(error); }; }); const successResponse = ` Opencode Antigravity OAuth

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`; const timeoutHandle = setTimeout(() => { rejectCallback(new Error("Timed out waiting for OAuth callback")); }, timeoutMs); timeoutHandle.unref?.(); const server = createServer((request, response) => { if (!request.url) { response.writeHead(400, { "Content-Type": "text/plain" }); response.end("Invalid request"); return; } const url = new URL(request.url, origin); if (url.pathname !== callbackPath) { response.writeHead(404, { "Content-Type": "text/plain" }); response.end("Not found"); return; } response.writeHead(200, { "Content-Type": "text/html; charset=utf-8" }); response.end(successResponse); resolveCallback(url); setImmediate(() => { server.close(); }); }); await new Promise((resolve, reject) => { const handleError = (error: Error) => { server.off("error", handleError); reject(error); }; server.once("error", handleError); server.listen(port, "127.0.0.1", () => { server.off("error", handleError); resolve(); }); }); server.on("error", (error) => { rejectCallback(error instanceof Error ? error : new Error(String(error))); }); return { waitForCallback: () => callbackPromise, close: () => new Promise((resolve, reject) => { server.close((error) => { if (error && (error as NodeJS.ErrnoException).code !== "ERR_SERVER_NOT_RUNNING") { reject(error); return; } if (!settled) { rejectCallback(new Error("OAuth listener closed before callback")); } resolve(); }); }), }; }