diff --git a/frontend/src/lib/components/AiToolPanel.svelte b/frontend/src/lib/components/AiToolPanel.svelte
index 1ba8218..0f2eb14 100644
--- a/frontend/src/lib/components/AiToolPanel.svelte
+++ b/frontend/src/lib/components/AiToolPanel.svelte
@@ -7,12 +7,15 @@
 	 *
 	 * Retning bestemmes av interaksjon:
 	 * - Dra en node HIT → node_to_tool (ny node med AI-output)
-	 * - Dra verktøyet PÅ en node → tool_to_node (in-place revisjon)
-	 * For nå støtter panelet kun node_to_tool (drop-mottak).
+	 * - Dra et preset PÅ en node → tool_to_node (in-place revisjon)
+	 *
+	 * Drop-sonen bruker presetets farge for visuell feedback.
+	 * Inkompatible noder (lyd, bilde) får rød sone med forklaring.
 	 */
 	import type { Node } from '$lib/spacetime';
 	import { nodeStore } from '$lib/spacetime';
 	import { aiProcess } from '$lib/api';
+	import { getDragPayload, checkAiToolCompat, setDragPayload } from '$lib/transfer';
 
 	interface Props {
 		accessToken?: string;
@@ -25,6 +28,7 @@
 	let selectedPresetId = $state<string | null>(null);
 	let customPrompt = $state('');
 	let dragOver = $state(false);
+	let dragIncompat = $state<{ reason: string; suggestion?: string } | null>(null);
 	let processing = $state(false);
 	let lastResult = $state<{ success: boolean; message: string } | null>(null);
 	let droppedNodeId = $state<string | null>(null);
@@ -32,7 +36,6 @@
 	// --- Derived: AI-preset noder fra STDB ---
 	const presets = $derived.by(() => {
 		const all = nodeStore.byKind('ai_preset');
-		// Sorter: standard først, deretter custom, alfabetisk innenfor
 		return all.sort((a, b) => {
 			const metaA = parseMetadata(a);
 			const metaB = parseMetadata(b);
@@ -49,6 +52,9 @@
 
 	const selectedMeta = $derived(selectedPreset ? parseMetadata(selectedPreset) : null);
 
+	/** The color of the selected preset, used for drop-zone feedback */
+	const presetColor = $derived((selectedMeta?.color as string) ?? '#9333ea');
+
 	const modelLabel = $derived.by(() => {
 		if (!selectedMeta) return '';
 		switch (selectedMeta.model_profile) {
@@ -75,7 +81,6 @@
 
 	function presetIcon(meta: Record<string, unknown>): string {
 		const icon = meta.icon as string;
-		// Map heroicon names to unicode/emoji approximations
 		const iconMap: Record<string, string> = {
 			sparkles: '✨',
 			check_badge: '✅',
@@ -89,56 +94,78 @@
 		return iconMap[icon] ?? '🤖';
 	}
 
-	// --- Drag-and-drop ---
+	// --- Drag-and-drop: receiving nodes ---
 	function handleDragOver(e: DragEvent) {
 		e.preventDefault();
-		if (e.dataTransfer) {
-			e.dataTransfer.dropEffect = 'copy';
+		if (!e.dataTransfer) return;
+
+		// Check compatibility during drag-over for visual feedback
+		const payload = getDragPayload(e.dataTransfer);
+		if (payload) {
+			const node = nodeStore.get(payload.nodeId);
+			if (node) {
+				const compat = checkAiToolCompat(node.nodeKind, !!node.content?.trim());
+				if (!compat.compatible) {
+					dragIncompat = { reason: compat.reason!, suggestion: compat.suggestion };
+					e.dataTransfer.dropEffect = 'none';
+					dragOver = true;
+					return;
+				}
+			}
 		}
+
+		dragIncompat = null;
+		e.dataTransfer.dropEffect = 'copy';
 		dragOver = true;
 	}
 
 	function handleDragLeave(e: DragEvent) {
-		// Only leave if actually leaving the drop zone
 		const rect = (e.currentTarget as HTMLElement).getBoundingClientRect();
 		const x = e.clientX;
 		const y = e.clientY;
 		if (x < rect.left || x > rect.right || y < rect.top || y > rect.bottom) {
 			dragOver = false;
+			dragIncompat = null;
 		}
 	}
 
 	function handleDrop(e: DragEvent) {
 		e.preventDefault();
 		dragOver = false;
+		dragIncompat = null;
 
-		const nodeId = e.dataTransfer?.getData('text/plain');
-		if (!nodeId) return;
+		if (!e.dataTransfer) return;
+		const payload = getDragPayload(e.dataTransfer);
+		if (!payload) return;
 
-		const node = nodeStore.get(nodeId);
+		const node = nodeStore.get(payload.nodeId);
 		if (!node) return;
 
-		// Sjekk kompatibilitet: kun tekstnoder
-		if (node.nodeKind !== 'content' && node.nodeKind !== 'communication') {
+		// Check compatibility
+		const compat = checkAiToolCompat(node.nodeKind, !!node.content?.trim());
+		if (!compat.compatible) {
 			lastResult = {
 				success: false,
-				message: `AI-verktøyet behandler kun tekst. "${node.title ?? 'Noden'}" er av type ${node.nodeKind}.`
+				message: [compat.reason, compat.suggestion].filter(Boolean).join(' ')
 			};
 			return;
 		}
 
-		if (!node.content?.trim()) {
-			lastResult = {
-				success: false,
-				message: 'Noden har ikke noe tekstinnhold å prosessere.'
-			};
-			return;
-		}
-
-		droppedNodeId = nodeId;
+		droppedNodeId = payload.nodeId;
 		lastResult = null;
 	}
 
+	// --- Drag-and-drop: dragging presets OUT (for tool_to_node) ---
+	function handlePresetDragStart(e: DragEvent, presetId: string) {
+		if (!e.dataTransfer) return;
+		setDragPayload(e.dataTransfer, {
+			nodeId: presetId,
+			nodeKind: 'ai_preset',
+			presetId,
+			sourcePanel: 'ai_tool'
+		});
+	}
+
 	// --- Prosessering ---
 	async function processNode() {
 		if (!accessToken || !selectedPresetId || !droppedNodeId) return;
@@ -188,7 +215,7 @@
 	</div>
 
 	<div class="p-4 space-y-4">
-		<!-- Prompt-velger -->
+		<!-- Prompt-velger (presets er draggable for tool_to_node) -->
 		<div>
 			<label for="ai-preset-select" class="block text-xs font-medium text-gray-500 mb-1">
 				Velg verktøy
@@ -201,17 +228,21 @@
 						{@const meta = parseMetadata(preset)}
 						<button
 							onclick={() => { selectedPresetId = preset.id; }}
-							class="flex items-center gap-1.5 rounded-lg border px-2.5 py-2 text-left text-xs transition-colors
+							draggable="true"
+							ondragstart={(e) => handlePresetDragStart(e, preset.id)}
+							class="flex items-center gap-1.5 rounded-lg border px-2.5 py-2 text-left text-xs transition-colors cursor-grab active:cursor-grabbing
 								{selectedPresetId === preset.id
 									? 'border-purple-400 bg-purple-50 text-purple-800 shadow-sm'
 									: 'border-gray-200 text-gray-600 hover:border-gray-300 hover:bg-gray-50'}"
-							style={selectedPresetId === preset.id ? `border-color: ${meta.color}` : ''}
+							style={selectedPresetId === preset.id && meta.color ? `border-color: ${meta.color}` : ''}
+							title="Klikk for å velge, eller dra til en tekstnode for in-place revisjon"
 						>
 							<span class="text-sm shrink-0">{presetIcon(meta)}</span>
 							<span class="truncate">{preset.title}</span>
 						</button>
 					{/each}
 				</div>
+				<p class="mt-1 text-xs text-gray-300">Dra et verktøy til en tekstnode for in-place revisjon</p>
 			{/if}
 		</div>
 
@@ -248,19 +279,21 @@
 			</p>
 		</div>
 
-		<!-- Drop-sone -->
+		<!-- Drop-sone med dynamisk farge fra valgt preset -->
 		<div
 			role="region"
 			aria-label="Slipp tekstnode her"
 			ondragover={handleDragOver}
 			ondragleave={handleDragLeave}
 			ondrop={handleDrop}
-			class="rounded-lg border-2 border-dashed p-6 text-center transition-colors
-				{dragOver
-					? 'border-purple-400 bg-purple-50'
-					: droppedNode
-						? 'border-green-300 bg-green-50'
-						: 'border-gray-200 bg-gray-50'}"
+			class="rounded-lg border-2 border-dashed p-6 text-center transition-colors"
+			class:border-gray-200={!dragOver && !droppedNode}
+			class:bg-gray-50={!dragOver && !droppedNode}
+			class:border-red-400={dragOver && dragIncompat}
+			class:bg-red-50={dragOver && dragIncompat}
+			class:border-green-300={!dragOver && !!droppedNode}
+			class:bg-green-50={!dragOver && !!droppedNode}
+			style={dragOver && !dragIncompat ? `border-color: ${presetColor}; background-color: ${presetColor}11;` : ''}
 		>
 			{#if droppedNode}
 				<!-- Viser droppet node -->
@@ -275,10 +308,10 @@
 						<button
 							onclick={processNode}
 							disabled={!selectedPresetId || processing}
-							class="rounded-lg px-4 py-1.5 text-xs font-medium text-white transition-colors
-								{!selectedPresetId || processing
-									? 'bg-gray-300 cursor-not-allowed'
-									: 'bg-purple-600 hover:bg-purple-700'}"
+							class="rounded-lg px-4 py-1.5 text-xs font-medium text-white transition-colors"
+							class:bg-gray-300={!selectedPresetId || processing}
+							class:cursor-not-allowed={!selectedPresetId || processing}
+							style={selectedPresetId && !processing ? `background-color: ${presetColor};` : ''}
 						>
 							{#if processing}
 								Prosesserer…
@@ -294,8 +327,14 @@
 						</button>
 					</div>
 				</div>
+			{:else if dragOver && dragIncompat}
+				<!-- Inkompatibel node -->
+				<p class="text-sm text-red-600 font-medium">{dragIncompat.reason}</p>
+				{#if dragIncompat.suggestion}
+					<p class="text-xs text-red-400 mt-1">{dragIncompat.suggestion}</p>
+				{/if}
 			{:else if dragOver}
-				<p class="text-sm text-purple-600 font-medium">Slipp her for AI-prosessering</p>
+				<p class="text-sm font-medium" style="color: {presetColor};">Slipp her for AI-prosessering</p>
 			{:else}
 				<p class="text-sm text-gray-400">Dra en tekstnode hit</p>
 				<p class="text-xs text-gray-300 mt-1">Støtter innholds- og kommunikasjonsnoder</p>
diff --git a/frontend/src/lib/components/traits/ChatTrait.svelte b/frontend/src/lib/components/traits/ChatTrait.svelte
index 00283a6..1810008 100644
--- a/frontend/src/lib/components/traits/ChatTrait.svelte
+++ b/frontend/src/lib/components/traits/ChatTrait.svelte
@@ -1,6 +1,7 @@
 <script lang="ts">
 	import type { Node } from '$lib/spacetime';
 	import { edgeStore, nodeStore } from '$lib/spacetime';
+	import { setDragPayload } from '$lib/transfer';
 	import TraitPanel from './TraitPanel.svelte';
 
 	interface Props {
@@ -31,6 +32,15 @@
 		}
 		return nodes;
 	});
+
+	function handleDragStart(e: DragEvent, node: Node) {
+		if (!e.dataTransfer) return;
+		setDragPayload(e.dataTransfer, {
+			nodeId: node.id,
+			nodeKind: node.nodeKind,
+			sourcePanel: 'chat'
+		});
+	}
 </script>
 
 <TraitPanel name="chat" label="Samtaler" icon="💬">
@@ -40,7 +50,11 @@
 		{:else}
 			<ul class="space-y-2">
 				{#each chatNodes as node (node.id)}
-					<li>
+					<li
+						draggable="true"
+						ondragstart={(e) => handleDragStart(e, node)}
+						class="cursor-grab active:cursor-grabbing"
+					>
 						<a
 							href="/chat/{node.id}"
 							class="block rounded border border-gray-100 px-3 py-2 transition-colors hover:border-blue-300 hover:bg-blue-50"
diff --git a/frontend/src/lib/components/traits/EditorTrait.svelte b/frontend/src/lib/components/traits/EditorTrait.svelte
index 6153940..ff59176 100644
--- a/frontend/src/lib/components/traits/EditorTrait.svelte
+++ b/frontend/src/lib/components/traits/EditorTrait.svelte
@@ -1,9 +1,10 @@
 <script lang="ts">
 	import type { Node, Edge } from '$lib/spacetime';
 	import { edgeStore, nodeStore, nodeVisibility } from '$lib/spacetime';
-	import { deleteEdge } from '$lib/api';
+	import { deleteEdge, aiProcess } from '$lib/api';
 	import TraitPanel from './TraitPanel.svelte';
 	import PublishDialog from '$lib/components/PublishDialog.svelte';
+	import { getDragPayload, setDragPayload, checkToolToNodeCompat } from '$lib/transfer';
 
 	interface Props {
 		collection: Node;
@@ -59,7 +60,6 @@
 		if (!isPublishingCollection || !userId) return [];
 		const inCollection = new Set(contentItems.map(i => i.node.id));
 		const nodes: Node[] = [];
-		// Find content nodes owned by user that aren't in this collection
 		for (const edge of edgeStore.bySource(userId)) {
 			if (edge.edgeType !== 'owner') continue;
 			const node = nodeStore.get(edge.targetId);
@@ -82,6 +82,108 @@
 	let unpublishError = $state<string | null>(null);
 	let confirmUnpublish = $state<ContentItem | null>(null);
 
+	// --- AI tool_to_node drop state ---
+	let dropTargetNodeId = $state<string | null>(null);
+	let dropIncompat = $state<{ reason: string; suggestion?: string } | null>(null);
+	let aiProcessing = $state<string | null>(null);
+	let aiResult = $state<{ nodeId: string; success: boolean; message: string } | null>(null);
+
+	function parsePresetMetadata(presetId: string): Record<string, unknown> {
+		const node = nodeStore.get(presetId);
+		if (!node) return {};
+		try { return JSON.parse(node.metadata ?? '{}'); } catch { return {}; }
+	}
+
+	// --- Drag-and-drop: items as drag source ---
+	function handleItemDragStart(e: DragEvent, item: ContentItem) {
+		if (!e.dataTransfer) return;
+		setDragPayload(e.dataTransfer, {
+			nodeId: item.node.id,
+			nodeKind: item.node.nodeKind,
+			sourcePanel: 'editor'
+		});
+	}
+
+	// --- Drag-and-drop: accept AI preset drops (tool_to_node) ---
+	function handleItemDragOver(e: DragEvent, item: ContentItem) {
+		e.preventDefault();
+		if (!e.dataTransfer) return;
+
+		const payload = getDragPayload(e.dataTransfer);
+		if (!payload || payload.nodeKind !== 'ai_preset' || !payload.presetId) {
+			// Not an AI preset — ignore (don't accept arbitrary drops on items)
+			return;
+		}
+
+		const compat = checkToolToNodeCompat(item.node.nodeKind, !!item.node.content?.trim());
+		if (!compat.compatible) {
+			dropIncompat = { reason: compat.reason!, suggestion: compat.suggestion };
+			e.dataTransfer.dropEffect = 'none';
+		} else {
+			dropIncompat = null;
+			e.dataTransfer.dropEffect = 'copy';
+		}
+		dropTargetNodeId = item.node.id;
+	}
+
+	function handleItemDragLeave(e: DragEvent, item: ContentItem) {
+		const rect = (e.currentTarget as HTMLElement).getBoundingClientRect();
+		const x = e.clientX;
+		const y = e.clientY;
+		if (x < rect.left || x > rect.right || y < rect.top || y > rect.bottom) {
+			if (dropTargetNodeId === item.node.id) {
+				dropTargetNodeId = null;
+				dropIncompat = null;
+			}
+		}
+	}
+
+	async function handleItemDrop(e: DragEvent, item: ContentItem) {
+		e.preventDefault();
+		dropTargetNodeId = null;
+		dropIncompat = null;
+
+		if (!e.dataTransfer || !accessToken) return;
+		const payload = getDragPayload(e.dataTransfer);
+		if (!payload || payload.nodeKind !== 'ai_preset' || !payload.presetId) return;
+
+		const compat = checkToolToNodeCompat(item.node.nodeKind, !!item.node.content?.trim());
+		if (!compat.compatible) {
+			aiResult = {
+				nodeId: item.node.id,
+				success: false,
+				message: [compat.reason, compat.suggestion].filter(Boolean).join(' ')
+			};
+			return;
+		}
+
+		// Trigger tool_to_node AI processing
+		aiProcessing = item.node.id;
+		aiResult = null;
+
+		try {
+			const res = await aiProcess(accessToken, {
+				source_node_id: item.node.id,
+				ai_preset_id: payload.presetId,
+				direction: 'tool_to_node'
+			});
+			const presetNode = nodeStore.get(payload.presetId);
+			aiResult = {
+				nodeId: item.node.id,
+				success: true,
+				message: `${presetNode?.title ?? 'AI'}: jobb opprettet (${res.job_id.slice(0, 8)}…). Noden oppdateres i sanntid.`
+			};
+		} catch (err) {
+			aiResult = {
+				nodeId: item.node.id,
+				success: false,
+				message: `Feil: ${err instanceof Error ? err.message : String(err)}`
+			};
+		} finally {
+			aiProcessing = null;
+		}
+	}
+
 	async function handleUnpublish(item: ContentItem) {
 		if (!accessToken || unpublishing) return;
 		unpublishing = item.node.id;
@@ -123,52 +225,88 @@
 		{:else}
 			<ul class="space-y-2">
 				{#each contentItems as item (item.node.id)}
+					{@const isDropTarget = dropTargetNodeId === item.node.id}
+					{@const isIncompat = isDropTarget && dropIncompat}
+					{@const isProcessing = aiProcessing === item.node.id}
+					{@const itemResult = aiResult?.nodeId === item.node.id ? aiResult : null}
 					<li
-						class="group rounded border border-gray-100 px-3 py-2 cursor-grab active:cursor-grabbing"
-						draggable="true"
-						ondragstart={(e) => {
-							if (e.dataTransfer) {
-								e.dataTransfer.effectAllowed = 'copy';
-								e.dataTransfer.setData('text/plain', item.node.id);
-							}
-						}}
+						class="group rounded border px-3 py-2 transition-colors"
+						class:cursor-grab={!isProcessing}
+						class:active:cursor-grabbing={!isProcessing}
+						class:border-gray-100={!isDropTarget && !isProcessing}
+						class:border-purple-400={isDropTarget && !isIncompat}
+						class:bg-purple-50={isDropTarget && !isIncompat}
+						class:border-red-400={!!isIncompat}
+						class:bg-red-50={!!isIncompat}
+						class:border-amber-300={isProcessing}
+						class:bg-amber-50={isProcessing}
+						draggable={!isProcessing}
+						ondragstart={(e) => handleItemDragStart(e, item)}
+						ondragover={(e) => handleItemDragOver(e, item)}
+						ondragleave={(e) => handleItemDragLeave(e, item)}
+						ondrop={(e) => handleItemDrop(e, item)}
 					>
-						<div class="flex items-start justify-between gap-2">
-							<div class="min-w-0 flex-1">
-								<h4 class="text-sm font-medium text-gray-900">{item.node.title || 'Uten tittel'}</h4>
-								{#if item.node.content}
-									<p class="mt-0.5 text-xs text-gray-500 line-clamp-2">{item.node.content.slice(0, 140)}</p>
-								{/if}
-								{#if isPublishingCollection && pubSlug}
-									<p class="mt-1 text-xs text-gray-400">
-										/pub/{pubSlug}/{item.node.id.slice(0, 8)}
-									</p>
+						{#if isIncompat}
+							<!-- Incompat feedback overlay -->
+							<div class="text-center py-1">
+								<p class="text-xs text-red-600 font-medium">{dropIncompat?.reason}</p>
+								{#if dropIncompat?.suggestion}
+									<p class="text-xs text-red-400 mt-0.5">{dropIncompat.suggestion}</p>
 								{/if}
 							</div>
-							{#if isPublishingCollection && accessToken}
-								<div class="flex shrink-0 items-center gap-1">
-									{#if pubSlug}
-										<a
-											href="/api/pub/{pubSlug}/{item.node.id.slice(0, 8)}"
-											target="_blank"
-											rel="noopener"
-											class="rounded px-2 py-1 text-xs text-gray-500 opacity-0 group-hover:opacity-100 hover:bg-gray-100 hover:text-gray-700"
-											title="Se publisert artikkel"
-										>
-											Se
-										</a>
+						{:else if isDropTarget}
+							<!-- Compatible drop target -->
+							<div class="text-center py-1">
+								<p class="text-xs text-purple-600 font-medium">Slipp for in-place revisjon</p>
+							</div>
+						{:else}
+							<div class="flex items-start justify-between gap-2">
+								<div class="min-w-0 flex-1">
+									<h4 class="text-sm font-medium text-gray-900">
+										{item.node.title || 'Uten tittel'}
+										{#if isProcessing}
+											<span class="ml-1 text-xs text-amber-600">Prosesserer…</span>
+										{/if}
+									</h4>
+									{#if item.node.content}
+										<p class="mt-0.5 text-xs text-gray-500 line-clamp-2">{item.node.content.slice(0, 140)}</p>
+									{/if}
+									{#if isPublishingCollection && pubSlug}
+										<p class="mt-1 text-xs text-gray-400">
+											/pub/{pubSlug}/{item.node.id.slice(0, 8)}
+										</p>
+									{/if}
+									{#if itemResult}
+										<p class="mt-1 text-xs {itemResult.success ? 'text-green-600' : 'text-red-600'}">
+											{itemResult.message}
+										</p>
 									{/if}
-									<button
-										onclick={() => { confirmUnpublish = item; }}
-										class="rounded px-2 py-1 text-xs text-red-500 opacity-0 group-hover:opacity-100 hover:bg-red-50 hover:text-red-700"
-										title="Fjern fra publisering"
-										disabled={unpublishing === item.node.id}
-									>
-										{unpublishing === item.node.id ? '...' : 'Avpubliser'}
-									</button>
 								</div>
-							{/if}
-						</div>
+								{#if isPublishingCollection && accessToken}
+									<div class="flex shrink-0 items-center gap-1">
+										{#if pubSlug}
+											<a
+												href="/api/pub/{pubSlug}/{item.node.id.slice(0, 8)}"
+												target="_blank"
+												rel="noopener"
+												class="rounded px-2 py-1 text-xs text-gray-500 opacity-0 group-hover:opacity-100 hover:bg-gray-100 hover:text-gray-700"
+												title="Se publisert artikkel"
+											>
+												Se
+											</a>
+										{/if}
+										<button
+											onclick={() => { confirmUnpublish = item; }}
+											class="rounded px-2 py-1 text-xs text-red-500 opacity-0 group-hover:opacity-100 hover:bg-red-50 hover:text-red-700"
+											title="Fjern fra publisering"
+											disabled={unpublishing === item.node.id}
+										>
+											{unpublishing === item.node.id ? '...' : 'Avpubliser'}
+										</button>
+									</div>
+								{/if}
+							</div>
+						{/if}
 					</li>
 				{/each}
 			</ul>
diff --git a/frontend/src/lib/transfer.ts b/frontend/src/lib/transfer.ts
new file mode 100644
index 0000000..14cd67b
--- /dev/null
+++ b/frontend/src/lib/transfer.ts
@@ -0,0 +1,120 @@
+/**
+ * Transfer service — drag-and-drop compatibility between tool panels.
+ *
+ * Centralizes compatibility checking and incompatibility messages
+ * for the universal transfer system (universell overføring).
+ *
+ * Ref: docs/features/universell_overfoering.md
+ * Ref: docs/retninger/arbeidsflaten.md § Kompatibilitetsmatrise
+ */
+
+export type ToolType = 'ai_tool' | 'editor' | 'chat' | 'kanban' | 'calendar' | 'studio';
+
+export interface DragPayload {
+	nodeId: string;
+	nodeKind: string;
+	/** Optional: AI preset ID when dragging from AI tool panel */
+	presetId?: string;
+	sourcePanel: ToolType;
+}
+
+export interface CompatResult {
+	compatible: boolean;
+	/** Human-readable reason when incompatible */
+	reason?: string;
+	/** Suggested alternative action */
+	suggestion?: string;
+}
+
+const MIME_TYPE = 'application/x-synops-transfer';
+
+/** Encode drag payload into dataTransfer */
+export function setDragPayload(dt: DataTransfer, payload: DragPayload): void {
+	dt.setData('text/plain', payload.nodeId);
+	dt.setData(MIME_TYPE, JSON.stringify(payload));
+	dt.effectAllowed = 'copy';
+}
+
+/** Decode drag payload from dataTransfer. Falls back to plain text node ID. */
+export function getDragPayload(dt: DataTransfer): DragPayload | null {
+	const json = dt.getData(MIME_TYPE);
+	if (json) {
+		try {
+			return JSON.parse(json) as DragPayload;
+		} catch { /* fall through */ }
+	}
+	const nodeId = dt.getData('text/plain');
+	if (nodeId) {
+		return { nodeId, nodeKind: 'unknown', sourcePanel: 'editor' as ToolType };
+	}
+	return null;
+}
+
+/** Media node kinds that are incompatible with text-only tools */
+const MEDIA_KINDS = new Set(['media', 'audio', 'image', 'video']);
+
+/** Check if a node kind represents media content */
+function isMediaKind(nodeKind: string): boolean {
+	return MEDIA_KINDS.has(nodeKind);
+}
+
+/** Check if a node kind represents audio */
+function isAudioKind(nodeKind: string): boolean {
+	return nodeKind === 'audio' || nodeKind === 'media'; // media is often audio in this context
+}
+
+/**
+ * Check compatibility for dropping a node onto the AI tool panel.
+ */
+export function checkAiToolCompat(nodeKind: string, hasContent: boolean): CompatResult {
+	if (isMediaKind(nodeKind)) {
+		return {
+			compatible: false,
+			reason: 'AI-verktøyet behandler kun tekst.',
+			suggestion: nodeKind === 'audio' || nodeKind === 'media'
+				? 'Transkriber lydfilen først, og dra transkripsjonen hit.'
+				: 'Kun tekstnoder kan prosesseres av AI-verktøyet.'
+		};
+	}
+	if (nodeKind !== 'content' && nodeKind !== 'communication') {
+		return {
+			compatible: false,
+			reason: `Nodetypen «${nodeKind}» støttes ikke av AI-verktøyet.`,
+			suggestion: 'Kun innholds- og kommunikasjonsnoder med tekst kan prosesseres.'
+		};
+	}
+	if (!hasContent) {
+		return {
+			compatible: false,
+			reason: 'Noden har ikke noe tekstinnhold å prosessere.'
+		};
+	}
+	return { compatible: true };
+}
+
+/**
+ * Check compatibility for dropping an AI preset onto a content node
+ * (tool_to_node direction — in-place revision).
+ */
+export function checkToolToNodeCompat(nodeKind: string, hasContent: boolean): CompatResult {
+	if (isMediaKind(nodeKind)) {
+		return {
+			compatible: false,
+			reason: 'AI-verktøyet kan ikke revidere mediefiler.',
+			suggestion: 'Kun tekstnoder kan revideres in-place.'
+		};
+	}
+	if (nodeKind !== 'content') {
+		return {
+			compatible: false,
+			reason: `Kun innholdsnoder kan revideres in-place.`
+		};
+	}
+	if (!hasContent) {
+		return {
+			compatible: false,
+			reason: 'Noden har ikke noe tekstinnhold å revidere.'
+		};
+	}
+	return { compatible: true };
+}
diff --git a/tasks.md b/tasks.md
index 7b8eab6..1db9607 100644
--- a/tasks.md
+++ b/tasks.md
@@ -205,8 +205,7 @@ Ref: `docs/features/ai_verktoy.md`, `docs/retninger/arbeidsflaten.md`
 - [x] 18.2 AI-prosessering endepunkt: `POST /intentions/ai_process` med source_node_id, ai_preset_id, direction (node_to_tool / tool_to_node). Maskinrommet henter kilde-content og preset-prompt, mapper modellprofil → LiteLLM-alias, sender til AI Gateway. Logg forbruk i ai_usage_log.
 - [x] 18.3 Direction-logikk: `tool_to_node` → lagre original som revisjon, oppdater node content. `node_to_tool` → opprett ny node med AI-output, opprett `derived_from`-edge til kilde + `processed_by`-edge til AI-preset.
 - [x] 18.4 AI-verktøy panel (frontend): Svelte-komponent for arbeidsflaten. Prompt-velger med standardprompter, fritekst-felt for egendefinert prompt, modell-indikator (readonly). Drag-and-drop mottak for tekstnoder.
-- [~] 18.5 Drag-and-drop integrasjon: node → verktøy (ny node), verktøy → node (in-place revisjon). Drop-sone feedback med verktøyets farge. Inkompatibilitet for lyd/bilde-noder med forklaring.
-  > Påbegynt: 2026-03-18T06:51
+- [x] 18.5 Drag-and-drop integrasjon: node → verktøy (ny node), verktøy → node (in-place revisjon). Drop-sone feedback med verktøyets farge. Inkompatibilitet for lyd/bilde-noder med forklaring.
 - [ ] 18.6 Egendefinerte presets: brukere kan opprette egne AI-preset-noder med custom prompt. Dele via edges til samling/team. Modellprofil satt av admin.
 
 ## Fase 19: Arbeidsflaten — Spatial Canvas