Host Code Execution

Host Code Execution

Boundary

Use code_execution_remote only for shell-backed execution on the machine where A0 CLI is running. Shells, runtimes, and paths belong to the CLI host, not the Agent Zero server or Docker container.

If the task belongs inside Agent Zero's own runtime, use the normal server-side execution tool instead.

Browser boundary: do not use shell launchers such as xdg-open, sensible-browser, open, start, or Python webbrowser.open as a fallback for requests to use/control/open a page in the host browser. Use the browser tool instead; if it reports missing Chrome remote-debugging consent, stop and relay the chrome://inspect/#remote-debugging instructions.

Access Modes

• Remote execution can be disabled locally in the CLI. If the tool returns a disabled/no-client error, explain the required CLI toggle instead of falling back to the server runtime.
• Read&Write local file access allows mutating runtimes such as terminal, python, and nodejs.
• Read only local file access blocks mutating runtimes. runtime=output and runtime=reset remain available for existing sessions.

Runtimes

• Use runtime=terminal for shell commands, runtime=python for Python snippets, and runtime=nodejs for Node.js snippets.
• Reuse the same integer session while continuing a workflow; session state is local to the CLI frontend.
• Use runtime=output when a previous command is still running or returned before the shell reached a prompt.
• Use runtime=reset when a session is stuck and no replacement command needs to run yet.
• Use reset: true with runtime=terminal, python, or nodejs when a session is stuck and the next command should run immediately in a clean shell.
• Match the remote host shell syntax. A Windows CLI may need PowerShell syntax even when Agent Zero runs on Linux.

Failure Handling

• If no CLI is connected, ask the user to connect A0 CLI to this Agent Zero instance.
• If execution is disabled, tell the user to enable remote execution in the CLI.
• If mutating runtimes are blocked, tell the user to switch local file access to Read&Write with F3.
• If a request times out or the CLI disconnects, poll once if a session may still be running; otherwise summarize the failure and wait for reconnection.