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diff --git a/assets/htmx.sse.js b/assets/htmx.sse.js
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+++ b/assets/htmx.sse.js
@@ -0,0 +1,355 @@
+/*
+Server Sent Events Extension
+============================
+This extension adds support for Server Sent Events to htmx.  See /www/extensions/sse.md for usage instructions.
+
+*/
+
+(function() {
+
+	/** @type {import("../htmx").HtmxInternalApi} */
+	var api;
+
+	htmx.defineExtension("sse", {
+
+		/**
+		 * Init saves the provided reference to the internal HTMX API.
+		 * 
+		 * @param {import("../htmx").HtmxInternalApi} api 
+		 * @returns void
+		 */
+		init: function(apiRef) {
+			// store a reference to the internal API.
+			api = apiRef;
+
+			// set a function in the public API for creating new EventSource objects
+			if (htmx.createEventSource == undefined) {
+				htmx.createEventSource = createEventSource;
+			}
+		},
+
+		/**
+		 * onEvent handles all events passed to this extension.
+		 * 
+		 * @param {string} name 
+		 * @param {Event} evt 
+		 * @returns void
+		 */
+		onEvent: function(name, evt) {
+
+			switch (name) {
+
+				case "htmx:beforeCleanupElement":
+					var internalData = api.getInternalData(evt.target)
+					// Try to remove remove an EventSource when elements are removed
+					if (internalData.sseEventSource) {
+						internalData.sseEventSource.close();
+					}
+
+					return;
+
+				// Try to create EventSources when elements are processed
+				case "htmx:afterProcessNode":
+					ensureEventSourceOnElement(evt.target);
+					registerSSE(evt.target);
+			}
+		}
+	});
+
+	///////////////////////////////////////////////
+	// HELPER FUNCTIONS
+	///////////////////////////////////////////////
+
+
+	/**
+	 * createEventSource is the default method for creating new EventSource objects.
+	 * it is hoisted into htmx.config.createEventSource to be overridden by the user, if needed.
+	 * 
+	 * @param {string} url 
+	 * @returns EventSource
+	 */
+	function createEventSource(url) {
+		return new EventSource(url, { withCredentials: true });
+	}
+
+	function splitOnWhitespace(trigger) {
+		return trigger.trim().split(/\s+/);
+	}
+
+	function getLegacySSEURL(elt) {
+		var legacySSEValue = api.getAttributeValue(elt, "hx-sse");
+		if (legacySSEValue) {
+			var values = splitOnWhitespace(legacySSEValue);
+			for (var i = 0; i < values.length; i++) {
+				var value = values[i].split(/:(.+)/);
+				if (value[0] === "connect") {
+					return value[1];
+				}
+			}
+		}
+	}
+
+	function getLegacySSESwaps(elt) {
+		var legacySSEValue = api.getAttributeValue(elt, "hx-sse");
+		var returnArr = [];
+		if (legacySSEValue != null) {
+			var values = splitOnWhitespace(legacySSEValue);
+			for (var i = 0; i < values.length; i++) {
+				var value = values[i].split(/:(.+)/);
+				if (value[0] === "swap") {
+					returnArr.push(value[1]);
+				}
+			}
+		}
+		return returnArr;
+	}
+
+	/**
+	 * registerSSE looks for attributes that can contain sse events, right 
+	 * now hx-trigger and sse-swap and adds listeners based on these attributes too
+	 * the closest event source
+	 *
+	 * @param {HTMLElement} elt
+	 */
+	function registerSSE(elt) {
+		// Find closest existing event source
+		var sourceElement = api.getClosestMatch(elt, hasEventSource);
+		if (sourceElement == null) {
+			// api.triggerErrorEvent(elt, "htmx:noSSESourceError")
+			return null; // no eventsource in parentage, orphaned element
+		}
+
+		// Set internalData and source
+		var internalData = api.getInternalData(sourceElement);
+		var source = internalData.sseEventSource;
+
+		// Add message handlers for every `sse-swap` attribute
+		queryAttributeOnThisOrChildren(elt, "sse-swap").forEach(function(child) {
+
+			var sseSwapAttr = api.getAttributeValue(child, "sse-swap");
+			if (sseSwapAttr) {
+				var sseEventNames = sseSwapAttr.split(",");
+			} else {
+				var sseEventNames = getLegacySSESwaps(child);
+			}
+
+			for (var i = 0; i < sseEventNames.length; i++) {
+				var sseEventName = sseEventNames[i].trim();
+				var listener = function(event) {
+
+					// If the source is missing then close SSE
+					if (maybeCloseSSESource(sourceElement)) {
+						return;
+					}
+
+					// If the body no longer contains the element, remove the listener
+					if (!api.bodyContains(child)) {
+						source.removeEventListener(sseEventName, listener);
+					}
+
+					// swap the response into the DOM and trigger a notification
+					swap(child, event.data);
+					api.triggerEvent(elt, "htmx:sseMessage", event);
+				};
+
+				// Register the new listener
+				api.getInternalData(child).sseEventListener = listener;
+				source.addEventListener(sseEventName, listener);
+			}
+		});
+
+		// Add message handlers for every `hx-trigger="sse:*"` attribute
+		queryAttributeOnThisOrChildren(elt, "hx-trigger").forEach(function(child) {
+
+			var sseEventName = api.getAttributeValue(child, "hx-trigger");
+			if (sseEventName == null) {
+				return;
+			}
+
+			// Only process hx-triggers for events with the "sse:" prefix
+			if (sseEventName.slice(0, 4) != "sse:") {
+				return;
+			}
+			
+			// remove the sse: prefix from here on out
+			sseEventName = sseEventName.substr(4);
+
+			var listener = function() {
+				if (maybeCloseSSESource(sourceElement)) {
+					return
+				}
+
+				if (!api.bodyContains(child)) {
+					source.removeEventListener(sseEventName, listener);
+				}
+			}
+		});
+	}
+
+	/**
+	 * ensureEventSourceOnElement creates a new EventSource connection on the provided element.
+	 * If a usable EventSource already exists, then it is returned.  If not, then a new EventSource
+	 * is created and stored in the element's internalData.
+	 * @param {HTMLElement} elt
+	 * @param {number} retryCount
+	 * @returns {EventSource | null}
+	 */
+	function ensureEventSourceOnElement(elt, retryCount) {
+
+		if (elt == null) {
+			return null;
+		}
+
+		// handle extension source creation attribute
+		queryAttributeOnThisOrChildren(elt, "sse-connect").forEach(function(child) {
+			var sseURL = api.getAttributeValue(child, "sse-connect");
+			if (sseURL == null) {
+				return;
+			}
+
+			ensureEventSource(child, sseURL, retryCount);
+		});
+
+		// handle legacy sse, remove for HTMX2
+		queryAttributeOnThisOrChildren(elt, "hx-sse").forEach(function(child) {
+			var sseURL = getLegacySSEURL(child);
+			if (sseURL == null) {
+				return;
+			}
+
+			ensureEventSource(child, sseURL, retryCount);
+		});
+
+	}
+
+	function ensureEventSource(elt, url, retryCount) {
+		var source = htmx.createEventSource(url);
+
+		source.onerror = function(err) {
+
+			// Log an error event
+			api.triggerErrorEvent(elt, "htmx:sseError", { error: err, source: source });
+
+			// If parent no longer exists in the document, then clean up this EventSource
+			if (maybeCloseSSESource(elt)) {
+				return;
+			}
+
+			// Otherwise, try to reconnect the EventSource
+			if (source.readyState === EventSource.CLOSED) {
+				retryCount = retryCount || 0;
+				var timeout = Math.random() * (2 ^ retryCount) * 500;
+				window.setTimeout(function() {
+					ensureEventSourceOnElement(elt, Math.min(7, retryCount + 1));
+				}, timeout);
+			}
+		};
+
+		source.onopen = function(evt) {
+			api.triggerEvent(elt, "htmx:sseOpen", { source: source });
+		}
+
+		api.getInternalData(elt).sseEventSource = source;
+	}
+
+	/**
+	 * maybeCloseSSESource confirms that the parent element still exists.
+	 * If not, then any associated SSE source is closed and the function returns true.
+	 * 
+	 * @param {HTMLElement} elt 
+	 * @returns boolean
+	 */
+	function maybeCloseSSESource(elt) {
+		if (!api.bodyContains(elt)) {
+			var source = api.getInternalData(elt).sseEventSource;
+			if (source != undefined) {
+				source.close();
+				// source = null
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * queryAttributeOnThisOrChildren returns all nodes that contain the requested attributeName, INCLUDING THE PROVIDED ROOT ELEMENT.
+	 * 
+	 * @param {HTMLElement} elt 
+	 * @param {string} attributeName 
+	 */
+	function queryAttributeOnThisOrChildren(elt, attributeName) {
+
+		var result = [];
+
+		// If the parent element also contains the requested attribute, then add it to the results too.
+		if (api.hasAttribute(elt, attributeName)) {
+			result.push(elt);
+		}
+
+		// Search all child nodes that match the requested attribute
+		elt.querySelectorAll("[" + attributeName + "], [data-" + attributeName + "]").forEach(function(node) {
+			result.push(node);
+		});
+
+		return result;
+	}
+
+	/**
+	 * @param {HTMLElement} elt
+	 * @param {string} content 
+	 */
+	function swap(elt, content) {
+
+		api.withExtensions(elt, function(extension) {
+			content = extension.transformResponse(content, null, elt);
+		});
+
+		var swapSpec = api.getSwapSpecification(elt);
+		var target = api.getTarget(elt);
+		var settleInfo = api.makeSettleInfo(elt);
+
+		api.selectAndSwap(swapSpec.swapStyle, target, elt, content, settleInfo);
+
+		settleInfo.elts.forEach(function(elt) {
+			if (elt.classList) {
+				elt.classList.add(htmx.config.settlingClass);
+			}
+			api.triggerEvent(elt, 'htmx:beforeSettle');
+		});
+
+		// Handle settle tasks (with delay if requested)
+		if (swapSpec.settleDelay > 0) {
+			setTimeout(doSettle(settleInfo), swapSpec.settleDelay);
+		} else {
+			doSettle(settleInfo)();
+		}
+	}
+
+	/**
+	 * doSettle mirrors much of the functionality in htmx that 
+	 * settles elements after their content has been swapped.
+	 * TODO: this should be published by htmx, and not duplicated here
+	 * @param {import("../htmx").HtmxSettleInfo} settleInfo 
+	 * @returns () => void
+	 */
+	function doSettle(settleInfo) {
+
+		return function() {
+			settleInfo.tasks.forEach(function(task) {
+				task.call();
+			});
+
+			settleInfo.elts.forEach(function(elt) {
+				if (elt.classList) {
+					elt.classList.remove(htmx.config.settlingClass);
+				}
+				api.triggerEvent(elt, 'htmx:afterSettle');
+			});
+		}
+	}
+
+	function hasEventSource(node) {
+		return api.getInternalData(node).sseEventSource != null;
+	}
+
+})();