dom wraps the browser DOM. It is a JavaScript module on the browser’s main thread, where document and window live. Import it by bare name or declare it in the host field of packages.json. The native engine rejects import dom at compile time, see the native engine.

The engine runs in a Web Worker, so each call crosses over postMessage and the script sees a synchronous call. Handlers that return a Promise suspend the calling coroutine and compose with gather, see Async.

Importing dom gives you a script-level facade over the internal _dom module that adds opt-in mutation batching. Inside a batch() block, mutators buffer locally and the block exit applies them with one host call. pending() counts buffered ops and flush() applies them early. Handles are opaque integers. Multi-result queries return CSV strings of handles. Structured returns are JSON strings, parse them with json. Async results (events, file reads, observer entries, animation finishes) arrive through receive() carrying a correlation handle. Detaching a node sweeps its handles, event bindings, and animations. bind_global_error(msg) routes async DOM callback errors to receive() instead of the browser console. The full handler inventory, by group:

• Selection and traversal: query, query_all, closest, matches, body, active_element, parent, children, first_child, last_child, next_sibling, prev_sibling, tag_name.
• Creation and mutation: create_element, create_element_ns, append_child, insert_before, remove, replace_children, clone_node.
• Content, attributes, classes: get_text, set_text, get_html, set_html, get_attribute, set_attribute, remove_attribute, add_class, remove_class, toggle_class, has_class, get_data, set_data.
• Style and layout: set_style, get_style, get_computed_style, rect, offset_width, offset_height, client_width, client_height, scroll_top, set_scroll_top, scroll_into_view, focus, blur.
• Events: bind_event, unbind_event, dispatch_event, click. Each fire delivers a JSON payload with msg, target_handle, and the event fields.
• Forms: get_value, set_value, get_checked, set_checked, form_submit, form_reset, form_data, is_valid, validity, report_validity, set_custom_validity, validation_message.
• Files: get_files, file_info, file_read_text, file_read_data_url.
• Observers: observe_intersection, observe_resize, observe_mutations, each with an unobserve_* counterpart.
• Animations: animate, animation_play, animation_pause, animation_cancel, animation_finish, animation_reverse, animation_dispose.
• Media: media_play, media_pause, get_current_time, set_current_time, get_duration, get_paused, set_volume, set_playback_rate.
• Platform: show_modal, dialog_close, request_fullscreen, exit_fullscreen, fullscreen_element, request_pointer_lock, exit_pointer_lock, plus SVG introspection bbox, path_length, point_at_length.