Is this issue fixed in a new version?

As of the latest tracking on GitHub (issue #8273), this remains a configuration requirement for sandboxed environments.

Will binding to 0.0.0.0 open a security hole?

It allows local connections from the Docker network. Ensure your host firewall (like UFW or iptables) is configured to restrict access to the specific browser bridge port if your machine is exposed to a public network.

Where is the browser.js file located?

It is typically found within your OpenClaw installation directory under 'agents/sandbox/browser.js'. Use 'find /path/to/openclaw -name "browser.js"' to locate it quickly.

How to Fix Browser Bridge Timeout in OpenClaw Sandboxed Agents

TL;DR — Quick Fix

The browser bridge binds to 127.0.0.1 by default, making it unreachable from your Docker container; you must force it to bind to 0.0.0.0 instead.

Run Diagnostics

Next Step

Fix now, then reduce repeat incidents

If this issue keeps coming back, validate your setup in Doctor first, then harden your config.

Open Doctor Harden Config

Error Signal

Can't reach the openclaw browser control service (timed out after 20000ms)

What's Happening

Your OpenClaw agent is timing out with the message: "Can't reach the openclaw browser control service (timed out after 20000ms)." This happens because the browser bridge server defaults to 127.0.0.1 (localhost). When your agent runs inside a Docker container, 'localhost' points to the container itself, not the gateway host where the bridge is actually running.

The Fix

You need to force the bridge to listen on all interfaces. Locate your browser.js file inside your OpenClaw installation and update the startBrowserBridgeServer call.

Run this command to automate the patch:

sed -i 's/return await startBrowserBridgeServer({/return await startBrowserBridgeServer({\n            host: "0.0.0.0",/' $(find /path/to/openclaw -name "browser.js" -path "*/sandbox/*")

If you prefer to edit the file manually, open agents/sandbox/browser.js and add host: "0.0.0.0" to the options object passed to startBrowserBridgeServer().

Why This Occurs

In browser/bridge-server.js, the default host is explicitly set to 127.0.0.1. Because agents/sandbox/browser.js invokes this server without overriding the host parameter, the bridge ignores external requests. Docker containers isolate network namespaces, so the agent container cannot reach the host's loopback interface. By binding to 0.0.0.0, the service accepts connections from any interface, including the bridge network used by Docker.

Prevention

Always ensure that services meant to be accessed by Dockerized agents are bound to the host's public bridge IP or 0.0.0.0 rather than loopback. This is a common pitfall in containerized architectures. If you deploy using custom Docker bridge configurations, verify your network settings allow communication between the agent container and the host service port.

Last Updated: March 2026

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