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 terminal return sandbox . terminal ( request , { cols : 80 , rows : 24 } ) ; TypeScript // Worker: proxy WebSocket to container terminal return 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 sandbox const dev = await sandbox . getSession ( "dev" ) ; return dev . terminal ( request ) ; TypeScript // Multiple isolated terminals in the same sandbox const 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