vercel-labs/agent-browser · error

The "goto" action requires a url.

Error message

The "goto" action requires a url.

What it means

The eve 'navigate' tool maps action 'goto' to 'agent-browser open <url>'. url is optional in the schema only because the other actions (back/forward/reload) take none; execute() throws when action is 'goto' and url is undefined so the CLI never receives a argument-less open.

Source

Thrown at packages/@agent-browser/eve/extension/tools/navigate.ts:19

import { defineTool } from "eve/tools";
import { z } from "zod";

import { runBrowser } from "../lib/browser";

export default defineTool({
  description:
    "Navigate the sandboxed browser: open a URL, or go back/forward/reload. Launches the browser on first use. After navigating, call the snapshot tool to see the page.",
  inputSchema: z.object({
    action: z
      .enum(["goto", "back", "forward", "reload"])
      .default("goto")
      .describe('"goto" opens the given URL; the others act on history.'),
    url: z.string().optional().describe('Required when action is "goto".'),
  }),
  async execute({ action, url }, ctx) {
    if (action === "goto") {
      if (url === undefined) {
        throw new Error('The "goto" action requires a url.');
      }
      return await runBrowser(ctx, ["open", url]);
    }
    return await runBrowser(ctx, [action]);
  },
});

View on GitHub (pinned to 548b159b30)

Solutions

1. Provide the url: tools.navigate({ action: 'goto', url: 'https://example.com' })
2. Or omit action entirely (it defaults to 'goto') but always include url
3. Use action 'reload'/'back'/'forward' when you do not want navigation to a URL

Example fix

// before
await tools.navigate({ action: "goto" });

// after
await tools.navigate({ action: "goto", url: "https://example.com" });

if ((input.action ?? "goto") === "goto" && input.url === undefined) {
  throw new Error("navigate to a URL requires the url field");
}

function canNavigate(i: { action?: string; url?: string }): boolean {
  const action = i.action ?? "goto";
  return action !== "goto" || i.url !== undefined;
}

When it happens

Trigger: Invoking navigate with { action: 'goto' } and no url; explicitly passing action: 'goto' while the url lives in an undefined variable; empty-string url is allowed by the schema but only undefined triggers this guard.

Common situations: Agents defaulting action to 'goto' without supplying the target; template code where the URL variable failed to resolve.

Related errors

• The "${action}" action requires a value.
• The "${property}" property requires a selector.
• The "attr" property requires an attribute name.
• Provide a direction to scroll, or a selector to scroll into
• The "switch" action requires a target tab id or label.

AI-assisted analysis of vercel-labs/agent-browser@548b159b30 (2026-08-16). Data as JSON: /api/errors/2ab82d927cb685d7. Report an issue: GitHub.