Agents - Interactive browser terminals in Sandboxes

The Sandbox SDK now supports PTY (pseudo-terminal) passthrough, enabling browser-based terminal UIs to connect to sandbox shells via WebSocket. sandbox.terminal(request) The new terminal() method proxies a WebSocket upgrade to the container's PTY endpoint, with output buffering for replay on reconnect. JavaScript // Worker: proxy WebSocket to container terminalreturn sandbox.terminal(request, { cols: 80, rows: 24 }); TypeScript // Worker: proxy WebSocket to container terminalreturn sandbox.terminal(request, { cols: 80, rows: 24 });
Multiple terminals per sandbox Each session can have its own terminal with an isolated working directory and environment, so users can run separate shells side-by-side in the same container. JavaScript // Multiple isolated terminals in the same sandboxconst dev = await sandbox.getSession("dev");return dev.terminal(request); TypeScript // Multiple isolated terminals in the same sandboxconst dev = await sandbox.getSession("dev");return dev.terminal(request);
xterm.js addon The new @cloudflare/sandbox/xterm export provides a SandboxAddon for xterm.js with automatic reconnection (exponential backoff + jitter), buffered output replay, and resize forwarding. JavaScript import { SandboxAddon } from "@cloudflare/sandbox/xterm"; const addon = new SandboxAddon({ getWebSocketUrl: ({ sandboxId, origin }) => ${origin}/ws/terminal?id=${sandboxId}, onStateChange: (state, error) => updateUI(state),});terminal.loadAddon(addon);addon.connect({ sandboxId: "my-sandbox" }); TypeScript import { SandboxAddon } from "@cloudflare/sandbox/xterm"; const addon = new SandboxAddon({ getWebSocketUrl: ({ sandboxId, origin }) => ${origin}/ws/terminal?id=${sandboxId}, onStateChange: (state, error) => updateUI(state),});terminal.loadAddon(addon);addon.connect({ sandboxId: "my-sandbox" });
Upgrade To update to the latest version: npm i @cloudflare/sandbox@latest