webui : add backend sampling options

tools/server/webui/src/lib/components/app/chat/ChatSettings/ChatSettingsDialog.svelte

@@ -152,6 +152,16 @@
 					key: 'samplers',
 					label: 'Samplers',
 					type: 'input'
+				},
+				{
+					key: 'backend_sampling',
+					label: 'Backend sampling',
+					type: 'checkbox'
+				},
+				{
+					key: 'backend_dist',
+					label: 'Backend dist sampling',
+					type: 'checkbox'
 				}
 			]
 		},
@@ -277,6 +287,10 @@
 
 	function handleConfigChange(key: string, value: string | boolean) {
 		localConfig[key] = value;
+
+		if (key === 'backend_sampling' && value === false) {
+			localConfig.backend_dist = false;
+		}
 	}
 
 	function handleClose() {

tools/server/webui/src/lib/components/app/chat/ChatSettings/ChatSettingsFields.svelte

@@ -198,7 +198,9 @@
 				</p>
 			{/if}
 		{:else if field.type === 'checkbox'}
-			{@const isDisabled = field.key === 'pdfAsImage' && !supportsVision()}
+			{@const pdfDisabled = field.key === 'pdfAsImage' && !supportsVision()}
+			{@const backendDistDisabled = field.key === 'backend_dist' && !localConfig.backend_sampling}
+			{@const isDisabled = pdfDisabled || backendDistDisabled}
 
 			<div class="flex items-start space-x-3">
 				<Checkbox
@@ -223,11 +225,15 @@
 						<p class="text-xs text-muted-foreground">
 							{field.help || SETTING_CONFIG_INFO[field.key]}
 						</p>
-					{:else if field.key === 'pdfAsImage' && !supportsVision()}
+					{:else if pdfDisabled}
 						<p class="text-xs text-muted-foreground">
 							PDF-to-image processing requires a vision-capable model. PDFs will be processed as
 							text.
 						</p>
+					{:else if backendDistDisabled}
+						<p class="text-xs text-muted-foreground">
+							Enable GPU sampling to allow GPU dist sampling.
+						</p>
 					{/if}
 				</div>
 			</div>

tools/server/webui/src/lib/constants/settings-config.ts

@@ -18,6 +18,8 @@ export const SETTING_CONFIG_DEFAULT: Record<string, string | number | boolean> =
 	modelSelectorEnabled: false,
 	// make sure these default values are in sync with `common.h`
 	samplers: 'top_k;typ_p;top_p;min_p;temperature',
+	backend_sampling: false,
+	backend_dist: false,
 	temperature: 0.8,
 	dynatemp_range: 0.0,
 	dynatemp_exponent: 1.0,
@@ -50,6 +52,10 @@ export const SETTING_CONFIG_INFO: Record<string, string> = {
 		'On pasting long text, it will be converted to a file. You can control the file length by setting the value of this parameter. Value 0 means disable.',
 	samplers:
 		'The order at which samplers are applied, in simplified way. Default is "top_k;typ_p;top_p;min_p;temperature": top_k->typ_p->top_p->min_p->temperature',
+	backend_sampling:
+		'Enable backend-based samplers. When enabled, supported samplers run on the accelerator backend for faster sampling.',
+	backend_dist:
+		'Perform the final distribution sampling step on the backend. Requires backend sampling to be enabled.',
 	temperature:
 		'Controls the randomness of the generated text by affecting the probability distribution of the output tokens. Higher = more random, lower = more focused.',
 	dynatemp_range:

tools/server/webui/src/lib/services/chat.ts

@@ -98,6 +98,8 @@ export class ChatService {
 			dry_penalty_last_n,
 			// Other parameters
 			samplers,
+			backend_sampling,
+			backend_dist,
 			custom,
 			timings_per_token
 		} = options;
@@ -182,6 +184,9 @@ export class ChatService {
 					: samplers;
 		}
 
+		if (backend_sampling !== undefined) requestBody.backend_sampling = backend_sampling;
+		if (backend_dist !== undefined) requestBody.backend_dist = backend_dist;
+
 		if (timings_per_token !== undefined) requestBody.timings_per_token = timings_per_token;
 
 		if (custom) {

tools/server/webui/src/lib/stores/chat.svelte.ts

@@ -298,6 +298,12 @@ class ChatStore {
 		if (currentConfig.samplers) {
 			apiOptions.samplers = currentConfig.samplers;
 		}
+		if (currentConfig.backend_sampling !== undefined) {
+			apiOptions.backend_sampling = Boolean(currentConfig.backend_sampling);
+		}
+		if (currentConfig.backend_dist !== undefined) {
+			apiOptions.backend_dist = Boolean(currentConfig.backend_dist);
+		}
 		if (currentConfig.custom) {
 			apiOptions.custom = currentConfig.custom;
 		}

tools/server/webui/src/lib/types/api.d.ts

@@ -181,6 +181,8 @@ export interface ApiChatCompletionRequest {
 	dry_penalty_last_n?: number;
 	// Sampler configuration
 	samplers?: string[];
+	backend_sampling?: boolean;
+	backend_dist?: boolean;
 	// Custom parameters (JSON string)
 	custom?: Record<string, unknown>;
 	timings_per_token?: boolean;

tools/server/webui/src/lib/types/settings.d.ts

@@ -36,6 +36,8 @@ export interface SettingsChatServiceOptions {
 	dry_penalty_last_n?: number;
 	// Sampler configuration
 	samplers?: string | string[];
+	backend_sampling?: boolean;
+	backend_dist?: boolean;
 	// Custom parameters
 	custom?: string;
 	timings_per_token?: boolean;