can1357/oh-my-pi · error · ToolError

Tab ${JSON.stringify(name)} is bound to a different browser

Error message

Tab ${JSON.stringify(name)} is bound to a different browser (${describeKind(existing.browser.kind)}). Close it first.

What it means

Named tabs are bound to a specific browser kind (e.g. managed CDP vs remote). If tab.open is called with a name that already exists on a different browser kind, the tool fails fast with this ToolError rather than silently migrating the tab; the caller must close the existing tab first.

Source

Thrown at packages/coding-agent/src/tools/browser.ts:270

			}
			throw error;
		}
	}

	async #open(
		name: string,
		params: BrowserParams,
		details: BrowserToolDetails,
		timeoutMs: number,
		signal?: AbortSignal,
	): Promise<AgentToolResult<BrowserToolDetails>> {
		const kind = resolveBrowserKind(params, this.session);
		details.browser = kind.kind;

		// If a tab with this name already exists on a different browser kind, fail fast — caller must close first.
		const existing = getTab(name);
		if (existing && !sameBrowserKind(existing.browser.kind, kind)) {
			throw new ToolError(
				`Tab ${JSON.stringify(name)} is bound to a different browser (${describeKind(existing.browser.kind)}). Close it first.`,
			);
		}

		// The requested timeout must cover the *entire* open — browser
		// acquisition (CDP discovery/connect), queued tab acquisition, worker
		// creation, and navigation — not only `acquireTab`. Compose one deadline
		// from the caller signal and `params.timeout` and thread it through both
		// stages so a stalled acquisition rejects at the requested boundary.
		// Capture the deadline start as well: `acquireTab` counts its
		// worker-init time against this same budget via `deadlineStartMs`
		// instead of restarting the clock after acquisition.
		const deadlineStart = performance.now();
		const timeoutSignal = AbortSignal.timeout(timeoutMs);
		const openSignal = signal ? AbortSignal.any([signal, timeoutSignal]) : timeoutSignal;
		try {
			const browser = await untilAborted(openSignal, () =>
				acquireBrowser(kind, {

View on GitHub (pinned to 9690622007)

Solutions

Close the existing tab with the same name first, then reopen with the new browser kind
Use a different tab name for the other browser kind
Make the browser kind explicit and consistent (same params/env) for a given tab name
Check resolveBrowserKind inputs (params.browser, session config) to see why the kind differs

Example fix

// before
await browser.run({ action: 'open', name: 'main', url }) // kind switched
// after
await browser.run({ action: 'close', name: 'main' });
await browser.run({ action: 'open', name: 'main', url });

Defensive patterns

Strategy: validation

Validate before calling

const existing = getTab?.(name); // or track locally
if (existing && existing.browserKind !== requestedKind) {
	await browser.run({ action: 'close', name });
}

Try / catch

try {
	await browser.run({ action: 'open', name, url });
} catch (err) {
	if (err instanceof ToolError && /bound to a different browser/.test(err.message)) {
		await browser.run({ action: 'close', name });
		await browser.run({ action: 'open', name, url });
	} else throw err;
}

Prevention

Keep a fixed browser kind per tab name
Close old tabs before switching browser configuration
Make the browser kind explicit in params instead of relying on ambient config
Avoid shared fixed tab names across sessions with different browser setups

When it happens

Trigger: Calling browser open with an existing tab name while switching the browser kind (params or session default changed); reusing a well-known tab name (e.g. 'main') after the environment switched between local and remote browsers; concurrent sessions sharing tab registry names with different kinds.

Common situations: Config change mid-session (CDP_ENDPOINT added/removed) altering resolveBrowserKind's result; tests reusing fixed tab names across suites with different browser setups; plugin/agent switching browser preference without closing tabs.

Related errors

AI-assisted analysis of can1357/oh-my-pi@9690622007 (2026-08-31). Data as JSON: /api/errors/5c7b8035dbb65dfe. Report an issue: GitHub.