jackwener/OpenCLI · critical · Error

Cannot connect to Antigravity at ${endpoint}. 1. Make sure

Error message

Cannot connect to Antigravity at ${endpoint}.
  1. Make sure Antigravity is running
  2. Launch with: --remote-debugging-port=9234

What it means

ensureConnected wraps CDP (Chrome DevTools Protocol) connection setup; when the underlying connection fails with ECONNREFUSED it rethrows this actionable error naming the Antigravity debug endpoint. Antigravity isn't listening on the remote-debugging port, so no browser automation can proceed.

Source

Thrown at clis/antigravity/serve.js:435

        // List available targets for debugging
        try {
            const res = await fetch(`${endpoint.replace(/\/$/, '')}/json`);
            const targets = await res.json();
            const pages = targets.filter(t => t.type === 'page');
            console.error(`[serve] Available targets: ${pages.map(t => `"${t.title}"`).join(', ')}`);
        }
        catch { /* ignore */ }
        console.error(`[serve] Connecting via CDP (target pattern: "${process.env.OPENCLI_CDP_TARGET}")...`);
        cdp = new CDPBridge();
        try {
            page = await cdp.connect({ timeout: 15_000, cdpEndpoint: endpoint });
        }
        catch (err) {
            cdp = null;
            const errMsg = getErrorMessage(err);
            const cause = err instanceof Error ? err.cause : undefined;
            const isRefused = cause?.code === 'ECONNREFUSED' || errMsg.includes('ECONNREFUSED');
            throw new Error(isRefused
                ? `Cannot connect to Antigravity at ${endpoint}.\n` +
                    '  1. Make sure Antigravity is running\n' +
                    '  2. Launch with: --remote-debugging-port=9234'
                : `CDP connection failed: ${errMsg}`);
        }
        console.error('[serve] ✅ CDP connected.');
        // Quick verification
        const hasUI = await page.evaluate(`
      (() => !!document.getElementById('conversation') || !!document.getElementById('antigravity.agentSidePanelInputBox'))()
    `);
        if (!hasUI) {
            console.error('[serve] ⚠️  Warning: chat UI elements not found in this target. Try setting OPENCLI_CDP_TARGET to the correct window title.');
        }
        return page;
    }
    const server = createServer(async (req, res) => {
        // CORS preflight
        if (req.method === 'OPTIONS') {

View on GitHub (pinned to 49907e53dc)

Solutions

1. Close and relaunch Antigravity with --remote-debugging-port=9234
2. Confirm Antigravity is fully running (open the window) before starting the serve process
3. Verify the endpoint/port matches how Antigravity was launched (curl http://127.0.0.1:9234/json/version)
4. Check that nothing else occupies the port and no firewall blocks it
5. Wait a few seconds after launching before connecting (startup race)

Example fix

// before
antigravity
// after
antigravity --remote-debugging-port=9234

async function cdpReachable(endpoint) {
  try {
    const res = await fetch(`http://${endpoint}/json/version`);
    return res.ok;
  } catch { return false; }
}
if (!await cdpReachable('127.0.0.1:9234')) {
  throw new Error('Start Antigravity with --remote-debugging-port=9234 first');
}

try {
  await client.connect(endpoint);
} catch (err) {
  if (String(err?.cause?.code || err.message).includes('ECONNREFUSED')) {
    console.error('Antigravity not reachable. Run: antigravity --remote-debugging-port=9234');
    process.exit(1);
  }
  throw err;
}

When it happens

Trigger: ensureConnected attempts the CDP WebSocket/HTTP connect to the endpoint (default port 9234), gets ECONNREFUSED (err.cause.code or message contains 'ECONNREFUSED'), and throws the formatted message; any other connect error becomes 'CDP connection failed: ...' instead.

Common situations: Antigravity launched normally without --remote-debugging-port=9234; Antigravity not running at all; wrong endpoint/port configured (env or flag); remote debugging port already bound by another instance then exited; firewall/container networking blocking localhost port; Antigravity still starting when the server connected.

Related errors

• 字幕获取失败: ${err?.message || err}
• Failed to fetch CDP targets: HTTP ${response.status}
• CDP not reachable at ${manualEndpoint}
• 12306 queryByTrainNo returned HTTP ${resp.status}
• 12306 queryByTrainNo returned non-JSON body

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/cd2f2be4b87aeca9. Report an issue: GitHub.