ui: model status and load progress via /models/sse feed (#24878)

* ui: model status and load progress via /models/sse feed

* ui: centralize SSE wire-format delimiters into shared constants for the chat and /models/sse parsers

* ui: type /models/sse event names as a ServerModelsSseEventType enum

Address review from allozaur

tools/ui/src/app.d.ts

@@ -19,6 +19,10 @@ import type {
 	ApiErrorResponse,
 	ApiLlamaCppServerProps,
 	ApiModelDataEntry,
+	ApiModelLoadStage,
+	ApiModelsSseProgress,
+	ApiModelsSseData,
+	ApiModelsSseEvent,
 	ApiModelListResponse,
 	ApiProcessingState,
 	ApiRouterModelMeta,
@@ -52,6 +56,7 @@ import type {
 	// Model types
 	ModelModalities,
 	ModelOption,
+	ModelLoadProgress,
 	// Settings types
 	SettingsChatServiceOptions,
 	SettingsConfigValue,
@@ -83,6 +88,10 @@ declare global {
 		ApiErrorResponse,
 		ApiLlamaCppServerProps,
 		ApiModelDataEntry,
+		ApiModelLoadStage,
+		ApiModelsSseProgress,
+		ApiModelsSseData,
+		ApiModelsSseEvent,
 		ApiModelListResponse,
 		ApiProcessingState,
 		ApiRouterModelMeta,
@@ -120,6 +129,7 @@ declare global {
 		// Model types
 		ModelModalities,
 		ModelOption,
+		ModelLoadProgress,
 		// Settings types
 		SettingsChatServiceOptions,
 		SettingsConfigValue,

tools/ui/src/lib/components/app/chat/ChatMessages/ChatMessage/ChatMessageAssistant/ChatMessageAssistant.svelte

@@ -10,7 +10,7 @@
 	import { getMessageEditContext } from '$lib/contexts';
 	import { useProcessingState } from '$lib/hooks/use-processing-state.svelte';
 	import { isLoading, isChatStreaming } from '$lib/stores/chat.svelte';
-	import { copyToClipboard, deriveAgenticSections } from '$lib/utils';
+	import { copyToClipboard, deriveAgenticSections, modelLoadProgressText } from '$lib/utils';
 	import { AgenticSectionType } from '$lib/enums';
 	import { REASONING_TAGS } from '$lib/constants/agentic';
 	import { tick } from 'svelte';
@@ -185,6 +185,13 @@
 	let hasNoContent = $derived(!message?.content?.trim());
 	let isActivelyProcessing = $derived(isCurrentlyLoading || isStreaming);
 
+	// during a router auto-load the message has no model yet, so target the selected one
+	let loadTargetModel = $derived(message.model ?? modelsStore.selectedModelName);
+	let modelLoadProgress = $derived(
+		isRouter && loadTargetModel ? modelsStore.getLoadProgress(loadTargetModel) : null
+	);
+	let modelLoadingText = $derived(modelLoadProgressText(modelLoadProgress));
+
 	let showProcessingInfoTop = $derived(
 		message?.role === MessageRole.ASSISTANT &&
 			isActivelyProcessing &&
@@ -220,7 +227,8 @@
 		<div class="mt-6 w-full max-w-[48rem]" in:fade>
 			<div class="processing-container">
 				<span class="processing-text">
-					{processingState.getPromptProgressText() ??
+					{modelLoadingText ??
+						processingState.getPromptProgressText() ??
 						processingState.getProcessingMessage() ??
 						'Processing...'}
 				</span>
@@ -252,7 +260,8 @@
 		<div class="mt-4 w-full max-w-[48rem]" in:fade>
 			<div class="processing-container">
 				<span class="processing-text">
-					{processingState.getPromptProgressText() ??
+					{modelLoadingText ??
+						processingState.getPromptProgressText() ??
 						processingState.getProcessingMessage() ??
 						'Processing...'}
 				</span>

tools/ui/src/lib/components/app/models/ModelsSelectorOption.svelte

@@ -13,6 +13,7 @@
 	import type { ModelOption } from '$lib/types/models';
 	import { ServerModelStatus } from '$lib/enums';
 	import { modelsStore, routerModels } from '$lib/stores/models.svelte';
+	import { modelLoadFraction, modelLoadProgressText } from '$lib/utils';
 
 	interface Props {
 		option: ModelOption;
@@ -50,11 +51,15 @@
 		(serverStatus === ServerModelStatus.LOADED || isSleeping) && !isOperationInProgress
 	);
 	let isLoading = $derived(serverStatus === ServerModelStatus.LOADING || isOperationInProgress);
+
+	let loadProgress = $derived(isLoading ? modelsStore.getLoadProgress(option.model) : null);
+	let loadPercent = $derived(Math.round(modelLoadFraction(loadProgress) * 100));
+	let loadTitle = $derived(modelLoadProgressText(loadProgress));
 </script>
 
 <div
 	class={[
-		'group flex w-full items-center gap-2 rounded-sm p-2 text-left text-sm transition focus:outline-none',
+		'group relative flex w-full items-center gap-2 rounded-sm p-2 text-left text-sm transition focus:outline-none',
 		'cursor-pointer hover:bg-muted focus:bg-muted',
 		(isSelected || isHighlighted) && 'bg-accent text-accent-foreground',
 		!(isSelected || isHighlighted) && 'hover:bg-accent hover:text-accent-foreground',
@@ -62,6 +67,7 @@
 	]}
 	role="option"
 	aria-selected={isSelected || isHighlighted}
+	title={loadTitle}
 	tabindex="0"
 	onclick={() => onSelect(option.id)}
 	onmouseenter={onMouseEnter}
@@ -188,4 +194,15 @@
 			</div>
 		{/if}
 	</div>
+
+	{#if isLoading}
+		<div
+			class="pointer-events-none absolute inset-x-0 bottom-0 h-0.5 overflow-hidden rounded-b-sm bg-muted"
+		>
+			<div
+				class="h-full bg-primary transition-[width] duration-200 ease-out"
+				style="width: {loadPercent}%"
+			></div>
+		</div>
+	{/if}
 </div>

tools/ui/src/lib/constants/api-endpoints.ts

@@ -1,7 +1,8 @@
 export const API_MODELS = {
 	LIST: '/v1/models',
 	LOAD: '/models/load',
-	UNLOAD: '/models/unload'
+	UNLOAD: '/models/unload',
+	SSE: '/models/sse'
 };
 
 // chat completion routes, the control route drives realtime inference (e.g. end reasoning)

tools/ui/src/lib/constants/index.ts

@@ -37,6 +37,8 @@ export * from './mcp-form';
 export * from './mcp-resource';
 export * from './message-export';
 export * from './model-id';
+export * from './model-loading';
+export * from './sse';
 export * from './precision';
 export * from './processing-info';
 export * from './pwa';

tools/ui/src/lib/constants/model-loading.ts

@@ -0,0 +1,14 @@
+/**
+ * Labels shown while a model loads, keyed by the stage reported on /models/sse.
+ */
+export const MODEL_LOAD_STAGE_LABELS: Record<ApiModelLoadStage, string> = {
+	text_model: 'Loading weights',
+	spec_model: 'Loading draft',
+	mmproj_model: 'Loading projector'
+};
+
+/**
+ * Share of the bar reserved for each load phase after text_model.
+ * text_model fills the rest, so a plain model reaches 100% on its own.
+ */
+export const MODEL_LOAD_TAIL_SHARE = 0.1;

tools/ui/src/lib/constants/sse.ts

@@ -0,0 +1,16 @@
+/**
+ * Server-sent events wire format, shared by the chat stream and the
+ * /models/sse status feed (text/event-stream).
+ */
+
+// blank line between two events
+export const SSE_RECORD_SEPARATOR = '\n\n';
+
+// line break inside an event
+export const SSE_LINE_SEPARATOR = '\n';
+
+// data field prefix, the value follows after an optional space
+export const SSE_DATA_PREFIX = 'data:';
+
+// end-of-stream marker on the chat completion stream
+export const SSE_DONE_MARKER = '[DONE]';

tools/ui/src/lib/enums/index.ts

@@ -54,7 +54,7 @@ export {
 
 export { ModelModality } from './model.enums';
 
-export { ServerRole, ServerModelStatus } from './server.enums';
+export { ServerRole, ServerModelStatus, ServerModelsSseEventType } from './server.enums';
 
 export { ParameterSource, SyncableParameterType, SettingsFieldType } from './settings.enums';
 

tools/ui/src/lib/enums/server.enums.ts

@@ -19,3 +19,17 @@ export enum ServerModelStatus {
 	SLEEPING = 'sleeping',
 	FAILED = 'failed'
 }
+
+/**
+ * /models/sse event type enum - discriminates the records broadcast on the
+ * model status feed in ROUTER mode. Matches the event names emitted by
+ * tools/server/server-models.cpp from the C++ server.
+ */
+export enum ServerModelsSseEventType {
+	STATUS_CHANGE = 'status_change',
+	MODEL_STATUS = 'model_status',
+	STATUS_UPDATE = 'status_update',
+	MODELS_RELOAD = 'models_reload',
+	MODEL_REMOVE = 'model_remove',
+	DOWNLOAD_PROGRESS = 'download_progress'
+}

tools/ui/src/lib/services/chat.service.ts

@@ -10,7 +10,10 @@ import {
 	SETTINGS_KEYS,
 	API_CHAT,
 	API_SLOTS,
-	CONTROL_ACTION
+	CONTROL_ACTION,
+	SSE_LINE_SEPARATOR,
+	SSE_DATA_PREFIX,
+	SSE_DONE_MARKER
 } from '$lib/constants';
 import {
 	AttachmentType,
@@ -18,8 +21,7 @@ import {
 	FileTypeAudio,
 	MessageRole,
 	MimeTypeAudio,
-	ReasoningFormat,
-	UrlProtocol
+	ReasoningFormat
 } from '$lib/enums';
 import type {
 	ApiChatMessageContentPart,
@@ -642,15 +644,15 @@ export class ChatService {
 				if (abortSignal?.aborted) break;
 
 				chunk += decoder.decode(value, { stream: true });
-				const lines = chunk.split('\n');
+				const lines = chunk.split(SSE_LINE_SEPARATOR);
 				chunk = lines.pop() || '';
 
 				for (const line of lines) {
 					if (abortSignal?.aborted) break;
 
-					if (line.startsWith(UrlProtocol.DATA)) {
-						const data = line.slice(6);
-						if (data === '[DONE]') {
+					if (line.startsWith(SSE_DATA_PREFIX)) {
+						const data = line.slice(SSE_DATA_PREFIX.length).trim();
+						if (data === SSE_DONE_MARKER) {
 							streamFinished = true;
 
 							continue;

tools/ui/src/lib/stores/models.svelte.ts

@@ -1,6 +1,7 @@
+import { base } from '$app/paths';
 import { SvelteMap, SvelteSet } from 'svelte/reactivity';
 import { toast } from 'svelte-sonner';
-import { ServerModelStatus, ModelModality } from '$lib/enums';
+import { ServerModelStatus, ServerModelsSseEventType, ModelModality } from '$lib/enums';
 import { ModelsService } from '$lib/services/models.service';
 import { PropsService } from '$lib/services/props.service';
 import { serverStore, isRouterMode } from '$lib/stores/server.svelte';
@@ -8,11 +9,15 @@ import {
 	detectThinkingSupport,
 	detectThinkingSupportWithReason
 } from '$lib/utils/chat-template-thinking-detector';
-import { TTLCache } from '$lib/utils';
+import { TTLCache, getAuthHeaders } from '$lib/utils';
 import {
 	MODEL_PROPS_CACHE_TTL_MS,
 	MODEL_PROPS_CACHE_MAX_ENTRIES,
-	FAVORITE_MODELS_LOCALSTORAGE_KEY
+	FAVORITE_MODELS_LOCALSTORAGE_KEY,
+	API_MODELS,
+	SSE_RECORD_SEPARATOR,
+	SSE_LINE_SEPARATOR,
+	SSE_DATA_PREFIX
 } from '$lib/constants';
 
 import { conversationsStore } from '$lib/stores/conversations.svelte';
@@ -55,6 +60,15 @@ class ModelsStore {
 	private modelUsage = $state<Map<string, SvelteSet<string>>>(new Map());
 	private modelLoadingStates = new SvelteMap<string, boolean>();
 
+	// /models/sse feed state, the single source of truth for status and load progress
+	private statusAbort: AbortController | null = null;
+	private statusReaderActive = false;
+	private loadProgress = new SvelteMap<string, ModelLoadProgress>();
+	private statusWaiters = new Map<
+		string,
+		{ target: ServerModelStatus; resolve: () => void; reject: (e: Error) => void }
+	>();
+
 	favoriteModelIds = $state<Set<string>>(this.loadFavoritesFromStorage());
 
 	/**
@@ -626,49 +640,218 @@ class ModelsStore {
 	 *
 	 */
 
-	/**
-	 * WORKAROUND: Polling for model status after load/unload operations.
-	 *
-	 * Currently, `/models/load` and `/models/unload` return success before
-	 * the operation actually completes on the server.
-	 *
-	 * TODO: Remove polling once llama-server properly waits for the operation
-	 * to complete before returning success.
-	 */
-
-	private static readonly STATUS_POLL_INTERVAL = 500;
+	// reconnect delay after the feed drops or the server is not ready yet
+	private static readonly SSE_RECONNECT_MS = 1000;
 
 	/**
-	 * Poll for expected model status after load/unload operation.
-	 * Keeps polling until the model reaches the expected status or fails.
+	 * Open the /models/sse feed and keep it live with auto reconnect.
+	 * Idempotent and router mode only. The feed drives status and progress,
+	 * so it replaces any post-operation polling.
 	 */
-	private async pollForModelStatus(
-		modelId: string,
-		expectedStatus: ServerModelStatus
-	): Promise<void> {
-		let attempt = 0;
-		while (true) {
-			await this.fetchRouterModels();
+	subscribeStatus(): void {
+		if (this.statusReaderActive) return;
+		if (!isRouterMode()) return;
 
-			const currentStatus = this.getModelStatus(modelId);
-			if (currentStatus === expectedStatus) return;
+		this.statusReaderActive = true;
+		this.statusAbort = new AbortController();
+		void this.runStatusReader(this.statusAbort.signal);
+	}
 
-			if (currentStatus === ServerModelStatus.FAILED) {
-				throw new Error(
-					`Model failed to ${expectedStatus === ServerModelStatus.LOADED ? 'load' : 'unload'}`
-				);
+	/**
+	 * Close the /models/sse feed and drop transient progress.
+	 */
+	unsubscribeStatus(): void {
+		this.statusReaderActive = false;
+		this.statusAbort?.abort();
+		this.statusAbort = null;
+		this.loadProgress.clear();
+	}
+
+	/**
+	 * Current load progress for a model, or null when not loading.
+	 */
+	getLoadProgress(modelId: string): ModelLoadProgress | null {
+		return this.loadProgress.get(modelId) ?? null;
+	}
+
+	/**
+	 * Read the feed and reconnect until unsubscribed. Splits the byte stream
+	 * into SSE records on the blank line boundary.
+	 */
+	private async runStatusReader(signal: AbortSignal): Promise<void> {
+		const decoder = new TextDecoder();
+
+		while (!signal.aborted) {
+			try {
+				const response = await fetch(`${base}${API_MODELS.SSE}`, {
+					headers: getAuthHeaders(),
+					signal
+				});
+
+				if (response.ok && response.body) {
+					const reader = response.body.getReader();
+					let buffer = '';
+
+					while (!signal.aborted) {
+						const { value, done } = await reader.read();
+						if (done) break;
+
+						buffer += decoder.decode(value, { stream: true });
+
+						let boundary = buffer.indexOf(SSE_RECORD_SEPARATOR);
+						while (boundary !== -1) {
+							this.handleStatusRecord(buffer.slice(0, boundary));
+							buffer = buffer.slice(boundary + SSE_RECORD_SEPARATOR.length);
+							boundary = buffer.indexOf(SSE_RECORD_SEPARATOR);
+						}
+					}
+				}
+			} catch {
+				// network drop or abort falls through to the reconnect delay
 			}
 
-			if (
-				expectedStatus === ServerModelStatus.LOADED &&
-				currentStatus === ServerModelStatus.UNLOADED &&
-				attempt > 2
-			) {
-				throw new Error('Model was unloaded unexpectedly during loading');
-			}
+			if (signal.aborted) return;
 
-			attempt++;
-			await new Promise((resolve) => setTimeout(resolve, ModelsStore.STATUS_POLL_INTERVAL));
+			await new Promise((resolve) => setTimeout(resolve, ModelsStore.SSE_RECONNECT_MS));
+		}
+	}
+
+	/**
+	 * Parse one SSE record. The payload rides in the data lines as a JSON
+	 * envelope that carries its own model, event and data fields.
+	 */
+	private handleStatusRecord(record: string): void {
+		const payload = record
+			.split(SSE_LINE_SEPARATOR)
+			.filter((line) => line.startsWith(SSE_DATA_PREFIX))
+			.map((line) => line.slice(SSE_DATA_PREFIX.length).trim())
+			.join(SSE_LINE_SEPARATOR);
+
+		if (payload.length === 0) return;
+
+		let envelope: ApiModelsSseEvent;
+		try {
+			envelope = JSON.parse(payload);
+		} catch {
+			return;
+		}
+
+		this.applyStatusEvent(envelope);
+	}
+
+	/**
+	 * Route one feed record by event kind. Only the status_* events carry a
+	 * status payload, models_reload triggers a list refresh, model_remove drops
+	 * the row, download_* belong to the download surface, not here.
+	 */
+	private applyStatusEvent(event: ApiModelsSseEvent): void {
+		switch (event.event) {
+			case ServerModelsSseEventType.STATUS_CHANGE:
+			case ServerModelsSseEventType.MODEL_STATUS:
+			case ServerModelsSseEventType.STATUS_UPDATE:
+				this.applyModelStatus(event);
+				break;
+			case ServerModelsSseEventType.MODELS_RELOAD:
+				void this.fetchRouterModels();
+				break;
+			case ServerModelsSseEventType.MODEL_REMOVE:
+				this.removeRouterModel(event.model);
+				break;
+			case ServerModelsSseEventType.DOWNLOAD_PROGRESS:
+				break;
+		}
+	}
+
+	/**
+	 * Apply a status envelope: update the model row, track or clear progress,
+	 * settle any pending load or unload awaiter.
+	 */
+	private applyModelStatus(event: ApiModelsSseEvent): void {
+		const model = event.model;
+		const data = event.data;
+		if (!model || !data?.status) return;
+
+		const status = data.status;
+
+		this.setRouterModelStatus(model, status);
+
+		if (status === ServerModelStatus.LOADING) {
+			if (data.progress) this.loadProgress.set(model, data.progress);
+		} else {
+			this.loadProgress.delete(model);
+		}
+
+		if (status === ServerModelStatus.LOADED) {
+			void this.updateModelModalities(model);
+		}
+
+		const failed =
+			status === ServerModelStatus.FAILED ||
+			(status === ServerModelStatus.UNLOADED && (data.exit_code ?? 0) !== 0);
+
+		if (failed) {
+			this.rejectStatus(model, new Error(`Model failed: ${this.toDisplayName(model)}`));
+			return;
+		}
+
+		this.settleStatus(model, status);
+	}
+
+	/**
+	 * Drop a model row reported gone by the feed and settle its awaiters.
+	 */
+	private removeRouterModel(modelId: string): void {
+		if (this.routerModels.findIndex((m) => m.id === modelId) === -1) return;
+
+		this.routerModels = this.routerModels.filter((m) => m.id !== modelId);
+		this.loadProgress.delete(modelId);
+		this.rejectStatus(modelId, new Error(`Model removed: ${this.toDisplayName(modelId)}`));
+	}
+
+	/**
+	 * Update one model row status in place, reassigning to trigger reactivity.
+	 */
+	private setRouterModelStatus(modelId: string, status: ServerModelStatus): void {
+		const idx = this.routerModels.findIndex((m) => m.id === modelId);
+		if (idx === -1) return;
+
+		const current = this.routerModels[idx];
+		if (current.status.value === status) return;
+
+		const next = [...this.routerModels];
+		next[idx] = { ...current, status: { ...current.status, value: status } };
+		this.routerModels = next;
+	}
+
+	/**
+	 * Register an awaiter that resolves when the feed reports target status.
+	 * One operation runs per model at a time, so one awaiter per model is kept.
+	 */
+	private waitForStatus(modelId: string, target: ServerModelStatus): Promise<void> {
+		return new Promise((resolve, reject) => {
+			this.statusWaiters.set(modelId, { target, resolve, reject });
+		});
+	}
+
+	/**
+	 * Resolve and drop the awaiter when the model reaches its target status.
+	 */
+	private settleStatus(modelId: string, status: ServerModelStatus): void {
+		const waiter = this.statusWaiters.get(modelId);
+		if (waiter && waiter.target === status) {
+			this.statusWaiters.delete(modelId);
+			waiter.resolve();
+		}
+	}
+
+	/**
+	 * Reject and drop the awaiter for a model.
+	 */
+	private rejectStatus(modelId: string, error: Error): void {
+		const waiter = this.statusWaiters.get(modelId);
+		if (waiter) {
+			this.statusWaiters.delete(modelId);
+			waiter.reject(error);
 		}
 	}
 
@@ -679,12 +862,18 @@ class ModelsStore {
 		this.modelLoadingStates.set(modelId, true);
 		this.error = null;
 
+		// the feed drives completion, so it must be live before the request
+		this.subscribeStatus();
+
+		const reachedLoaded = this.waitForStatus(modelId, ServerModelStatus.LOADED);
+		reachedLoaded.catch(() => {});
+
 		try {
 			await ModelsService.load(modelId);
-			await this.pollForModelStatus(modelId, ServerModelStatus.LOADED);
-			await this.updateModelModalities(modelId);
+			await reachedLoaded;
 			toast.success(`Model loaded: ${this.toDisplayName(modelId)}`);
 		} catch (error) {
+			this.rejectStatus(modelId, error instanceof Error ? error : new Error('load failed'));
 			this.error = error instanceof Error ? error.message : 'Failed to load model';
 			toast.error(`Failed to load model: ${this.toDisplayName(modelId)}`);
 			throw error;
@@ -700,11 +889,17 @@ class ModelsStore {
 		this.modelLoadingStates.set(modelId, true);
 		this.error = null;
 
+		this.subscribeStatus();
+
+		const reachedUnloaded = this.waitForStatus(modelId, ServerModelStatus.UNLOADED);
+		reachedUnloaded.catch(() => {});
+
 		try {
 			await ModelsService.unload(modelId);
-			await this.pollForModelStatus(modelId, ServerModelStatus.UNLOADED);
+			await reachedUnloaded;
 			toast.info(`Model unloaded: ${this.toDisplayName(modelId)}`);
 		} catch (error) {
+			this.rejectStatus(modelId, error instanceof Error ? error : new Error('unload failed'));
 			this.error = error instanceof Error ? error.message : 'Failed to unload model';
 			toast.error(`Failed to unload model: ${this.toDisplayName(modelId)}`);
 			throw error;
@@ -783,6 +978,9 @@ class ModelsStore {
 	}
 
 	clear(): void {
+		this.unsubscribeStatus();
+		this.statusWaiters.forEach((waiter) => waiter.reject(new Error('Models store cleared')));
+		this.statusWaiters.clear();
 		this.models = [];
 		this.routerModels = [];
 		this.loading = false;

tools/ui/src/lib/types/api.d.ts

@@ -1,4 +1,10 @@
-import type { ContentPartType, FileTypeAudio, ServerModelStatus, ServerRole } from '$lib/enums';
+import type {
+	ContentPartType,
+	FileTypeAudio,
+	ServerModelStatus,
+	ServerModelsSseEventType,
+	ServerRole
+} from '$lib/enums';
 import type { ChatMessagePromptProgress, ChatRole } from './chat';
 
 export type AudioInputFormat = FileTypeAudio.WAV | FileTypeAudio.MP3;
@@ -96,6 +102,46 @@ export interface ApiModelDataEntry {
 	meta?: Record<string, unknown> | null;
 }
 
+/**
+ * Load stage reported by the /models/sse feed, in load order.
+ */
+export type ApiModelLoadStage = 'text_model' | 'spec_model' | 'mmproj_model';
+
+/**
+ * Load progress snapshot: the full ordered stage plan, the active stage,
+ * and its fractional value (0.0 -> 1.0).
+ */
+export interface ApiModelsSseProgress {
+	stages: ApiModelLoadStage[];
+	current: ApiModelLoadStage;
+	value: number;
+}
+
+/**
+ * Status payload carried by a /models/sse envelope.
+ * exit_code appears on unload.
+ */
+export interface ApiModelsSseData {
+	status: ServerModelStatus;
+	progress?: ApiModelsSseProgress;
+	exit_code?: number;
+}
+
+/**
+ * Event kind multiplexed on the /models/sse feed.
+ * Only the status_* events carry a status payload, models_reload signals a
+ * full list refresh, model_remove drops a row, download_* drive download UI.
+ */
+/**
+ * One /models/sse record. event discriminates the kind, model names the
+ * target instance, data carries the status payload when present.
+ */
+export interface ApiModelsSseEvent {
+	model: string;
+	event: ServerModelsSseEventType;
+	data: ApiModelsSseData;
+}
+
 export interface ApiModelDetails {
 	name: string;
 	model: string;

tools/ui/src/lib/types/index.ts

@@ -11,6 +11,10 @@ export type {
 	ApiChatMessageData,
 	ApiModelStatus,
 	ApiModelDataEntry,
+	ApiModelLoadStage,
+	ApiModelsSseProgress,
+	ApiModelsSseData,
+	ApiModelsSseEvent,
 	ApiModelDetails,
 	ApiModelListResponse,
 	ApiLlamaCppServerProps,
@@ -70,7 +74,12 @@ export type {
 } from './database';
 
 // Model types
-export type { ModelModalities, ModelOption, ModalityCapabilities } from './models';
+export type {
+	ModelModalities,
+	ModelOption,
+	ModelLoadProgress,
+	ModalityCapabilities
+} from './models';
 
 // Settings types
 export type {

tools/ui/src/lib/types/models.d.ts

@@ -1,4 +1,4 @@
-import type { ApiModelDataEntry, ApiModelDetails } from '$lib/types/api';
+import type { ApiModelDataEntry, ApiModelDetails, ApiModelLoadStage } from '$lib/types/api';
 
 export interface ModelModalities {
 	vision: boolean;
@@ -20,6 +20,17 @@ export interface ModelOption {
 	tags?: string[];
 }
 
+/**
+ * Ephemeral UI-only load progress for one model instance.
+ * Lives only while a load runs, driven by the /models/sse feed.
+ * stage is absent until the feed reports its first stage.
+ */
+export interface ModelLoadProgress {
+	stages: ApiModelLoadStage[];
+	current: ApiModelLoadStage;
+	value: number;
+}
+
 export interface ParsedModelId {
 	raw: string;
 	orgName: string | null;

tools/ui/src/lib/utils/index.ts

@@ -44,6 +44,9 @@ export { buildProxiedUrl, buildProxiedHeaders } from './cors-proxy';
 // URL utilities
 export { extractRootDomain, sanitizeExternalUrl } from './url';
 
+// Progress helpers
+export { modelLoadFraction, modelLoadProgressText } from './progress';
+
 // Conversation utilities
 export { createMessageCountMap, getMessageCount } from './conversation-utils';
 

tools/ui/src/lib/utils/progress.ts

@@ -0,0 +1,43 @@
+/**
+ * Model load progress helpers for the /models/sse surfaces
+ * (selector row and chat message).
+ */
+
+import { MODEL_LOAD_STAGE_LABELS, MODEL_LOAD_TAIL_SHARE } from '$lib/constants';
+
+/**
+ * Human label for a model load stage.
+ */
+export function modelLoadStageLabel(stage: ApiModelLoadStage): string {
+	return MODEL_LOAD_STAGE_LABELS[stage];
+}
+
+/**
+ * Overall load fraction (0.0 -> 1.0) across the declared stage plan.
+ * text_model fills [0, 1 - tail], each later phase owns one tail slice.
+ */
+export function modelLoadFraction(progress: ModelLoadProgress | null): number {
+	if (!progress) return 0;
+
+	const { stages, current, value } = progress;
+	const tailCount = Math.max(stages.length - 1, 0);
+	const textCeiling = 1 - tailCount * MODEL_LOAD_TAIL_SHARE;
+	const idx = stages.indexOf(current);
+
+	if (idx <= 0) {
+		return value * textCeiling;
+	}
+
+	return textCeiling + (idx - 1 + value) * MODEL_LOAD_TAIL_SHARE;
+}
+
+/**
+ * Single line describing load progress: active stage label and overall percent.
+ * Returns null when there is no progress to show.
+ */
+export function modelLoadProgressText(progress: ModelLoadProgress | null): string | null {
+	if (!progress) return null;
+
+	const label = modelLoadStageLabel(progress.current);
+	return `${label} ${Math.round(modelLoadFraction(progress) * 100)}%`;
+}

tools/ui/src/routes/+layout.svelte

@@ -230,6 +230,20 @@
 		}
 	});
 
+	// Live model status and load progress via the /models/sse feed (router mode)
+	$effect(() => {
+		if (!browser) return;
+		if (!isRouterMode()) return;
+
+		untrack(() => {
+			modelsStore.subscribeStatus();
+		});
+
+		return () => {
+			modelsStore.unsubscribeStatus();
+		};
+	});
+
 	// Background MCP server health checks on app load
 	// Fetch enabled servers from settings and run health checks in background
 	$effect(() => {