diff --git a/packages/types/src/provider-settings.ts b/packages/types/src/provider-settings.ts
index 65e3f9b5b6..10216b84c0 100644
--- a/packages/types/src/provider-settings.ts
+++ b/packages/types/src/provider-settings.ts
@@ -56,6 +56,7 @@ const baseProviderSettingsSchema = z.object({
 	diffEnabled: z.boolean().optional(),
 	fuzzyMatchThreshold: z.number().optional(),
 	modelTemperature: z.number().nullish(),
+	modelSeed: z.number().optional(),
 	rateLimitSeconds: z.number().optional(),
 
 	// Model reasoning.
diff --git a/src/api/providers/base-openai-compatible-provider.ts b/src/api/providers/base-openai-compatible-provider.ts
index f196b5f309..256c8672ff 100644
--- a/src/api/providers/base-openai-compatible-provider.ts
+++ b/src/api/providers/base-openai-compatible-provider.ts
@@ -78,6 +78,7 @@ export abstract class BaseOpenAiCompatibleProvider<ModelName extends string>
 			model,
 			max_tokens,
 			temperature,
+			seed: this.options.modelSeed,
 			messages: [{ role: "system", content: systemPrompt }, ...convertToOpenAiMessages(messages)],
 			stream: true,
 			stream_options: { include_usage: true },
diff --git a/src/api/providers/openai.ts b/src/api/providers/openai.ts
index b4f256f43a..85521a1495 100644
--- a/src/api/providers/openai.ts
+++ b/src/api/providers/openai.ts
@@ -152,6 +152,7 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 			const requestOptions: OpenAI.Chat.Completions.ChatCompletionCreateParamsStreaming = {
 				model: modelId,
 				temperature: this.options.modelTemperature ?? (deepseekReasoner ? DEEP_SEEK_DEFAULT_TEMPERATURE : 0),
+				seed: this.options.modelSeed,
 				messages: convertedMessages,
 				stream: true as const,
 				...(isGrokXAI ? {} : { stream_options: { include_usage: true } }),
diff --git a/src/api/providers/openrouter.ts b/src/api/providers/openrouter.ts
index 26019ce34a..ee8dc103dd 100644
--- a/src/api/providers/openrouter.ts
+++ b/src/api/providers/openrouter.ts
@@ -116,6 +116,7 @@ export class OpenRouterHandler extends BaseProvider implements SingleCompletionH
 			model: modelId,
 			...(maxTokens && maxTokens > 0 && { max_tokens: maxTokens }),
 			temperature,
+			seed: this.options.modelSeed,
 			top_p: topP,
 			messages: openAiMessages,
 			stream: true,
@@ -219,6 +220,7 @@ export class OpenRouterHandler extends BaseProvider implements SingleCompletionH
 			model: modelId,
 			max_tokens: maxTokens,
 			temperature,
+			seed: this.options.modelSeed,
 			messages: [{ role: "user", content: prompt }],
 			stream: false,
 			// Only include provider if openRouterSpecificProvider is not "[default]".
diff --git a/webview-ui/src/components/settings/ApiOptions.tsx b/webview-ui/src/components/settings/ApiOptions.tsx
index 905f34a860..85a8da9715 100644
--- a/webview-ui/src/components/settings/ApiOptions.tsx
+++ b/webview-ui/src/components/settings/ApiOptions.tsx
@@ -53,6 +53,7 @@ import { DiffSettingsControl } from "./DiffSettingsControl"
 import { TemperatureControl } from "./TemperatureControl"
 import { RateLimitSecondsControl } from "./RateLimitSecondsControl"
 import { BedrockCustomArn } from "./providers/BedrockCustomArn"
+import { SeedControl } from "./SeedControl"
 import { buildDocLink } from "@src/utils/docLinks"
 
 export interface ApiOptionsProps {
@@ -488,6 +489,10 @@ const ApiOptions = ({
 						value={apiConfiguration.rateLimitSeconds || 0}
 						onChange={(value) => setApiConfigurationField("rateLimitSeconds", value)}
 					/>
+					<SeedControl
+						value={apiConfiguration.modelSeed}
+						onChange={handleInputChange("modelSeed", noTransform)}
+					/>
 				</>
 			)}
 		</div>
diff --git a/webview-ui/src/components/settings/SeedControl.tsx b/webview-ui/src/components/settings/SeedControl.tsx
new file mode 100644
index 0000000000..414914832b
--- /dev/null
+++ b/webview-ui/src/components/settings/SeedControl.tsx
@@ -0,0 +1,82 @@
+import { VSCodeCheckbox } from "@vscode/webview-ui-toolkit/react"
+import { useEffect, useState } from "react"
+import { useAppTranslation } from "@/i18n/TranslationContext"
+import { useDebounce } from "react-use"
+
+interface SeedControlProps {
+	value: number | undefined | null
+	onChange: (value: number | undefined) => void
+}
+
+export const SeedControl = ({ value, onChange }: SeedControlProps) => {
+	const { t } = useAppTranslation()
+	const [isCustomSeed, setIsCustomSeed] = useState(value !== undefined && value !== null)
+	const [inputValue, setInputValue] = useState<string>(value?.toString() ?? "")
+
+	useDebounce(
+		() => {
+			if (inputValue === "") {
+				onChange(undefined)
+			} else {
+				const numValue = parseInt(inputValue, 10)
+				if (!isNaN(numValue)) {
+					onChange(numValue)
+				}
+			}
+		},
+		50,
+		[onChange, inputValue],
+	)
+
+	// Sync internal state with prop changes when switching profiles.
+	useEffect(() => {
+		const hasCustomSeed = value !== undefined && value !== null
+		setIsCustomSeed(hasCustomSeed)
+		setInputValue(value?.toString() ?? "")
+	}, [value])
+
+	const handleCheckboxChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+		const isChecked = e.target.checked
+		setIsCustomSeed(isChecked)
+
+		if (!isChecked) {
+			setInputValue("")
+		} else {
+			setInputValue(value?.toString() ?? "42")
+		}
+	}
+
+	const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+		setInputValue(e.target.value)
+	}
+
+	return (
+		<>
+			<div>
+				<VSCodeCheckbox
+					checked={isCustomSeed}
+					onChange={(e) => {
+						handleCheckboxChange(e as React.ChangeEvent<HTMLInputElement>)
+					}}>
+					<label className="block font-medium mb-1">{t("settings:seed.useCustom")}</label>
+				</VSCodeCheckbox>
+				<div className="text-sm text-vscode-descriptionForeground mt-1">{t("settings:seed.description")}</div>
+			</div>
+
+			{isCustomSeed && (
+				<div className="flex flex-col gap-3 pl-3 border-l-2 border-vscode-button-background">
+					<div>
+						<input
+							type="number"
+							value={inputValue}
+							onChange={(e) => {
+								handleInputChange(e as React.ChangeEvent<HTMLInputElement>)
+							}}
+							className="w-full"
+						/>
+					</div>
+				</div>
+			)}
+		</>
+	)
+}
diff --git a/webview-ui/src/components/settings/__tests__/ApiOptions.test.tsx b/webview-ui/src/components/settings/__tests__/ApiOptions.test.tsx
index 17421d3960..3d0b6e00bc 100644
--- a/webview-ui/src/components/settings/__tests__/ApiOptions.test.tsx
+++ b/webview-ui/src/components/settings/__tests__/ApiOptions.test.tsx
@@ -21,6 +21,12 @@ jest.mock("@vscode/webview-ui-toolkit/react", () => ({
 	VSCodeRadio: ({ value, checked }: any) => <input type="radio" value={value} checked={checked} />,
 	VSCodeRadioGroup: ({ children }: any) => <div>{children}</div>,
 	VSCodeButton: ({ children }: any) => <div>{children}</div>,
+	VSCodeCheckbox: ({ children, checked, onChange }: any) => (
+		<label>
+			<input type="checkbox" checked={checked} onChange={onChange} />
+			{children}
+		</label>
+	),
 }))
 
 // Mock other components
diff --git a/webview-ui/src/i18n/locales/ca/settings.json b/webview-ui/src/i18n/locales/ca/settings.json
index c88005ea61..71451a2cc9 100644
--- a/webview-ui/src/i18n/locales/ca/settings.json
+++ b/webview-ui/src/i18n/locales/ca/settings.json
@@ -519,6 +519,11 @@
 		"description": "Controla l'aleatorietat en les respostes del model.",
 		"rangeDescription": "Valors més alts fan que la sortida sigui més aleatòria, valors més baixos la fan més determinista."
 	},
+	"seed": {
+		"useCustom": "Utilitzar llavor personalitzada",
+		"description": "Controla la naturalesa determinista de les respostes del model. Deixeu en blanc per a aleatori.",
+		"label": "Introduïu un valor de llavor"
+	},
 	"modelInfo": {
 		"supportsImages": "Suporta imatges",
 		"noImages": "No suporta imatges",
diff --git a/webview-ui/src/i18n/locales/de/settings.json b/webview-ui/src/i18n/locales/de/settings.json
index 27a7486436..a2c842f512 100644
--- a/webview-ui/src/i18n/locales/de/settings.json
+++ b/webview-ui/src/i18n/locales/de/settings.json
@@ -519,6 +519,11 @@
 		"description": "Steuert die Zufälligkeit in den Antworten des Modells.",
 		"rangeDescription": "Höhere Werte machen die Ausgabe zufälliger, niedrigere Werte machen sie deterministischer."
 	},
+	"seed": {
+		"useCustom": "Benutzerdefinierten Seed verwenden",
+		"description": "Steuert die deterministische Natur der Antworten des Modells. Für zufällig leer lassen.",
+		"label": "Einen Seed-Wert eingeben"
+	},
 	"modelInfo": {
 		"supportsImages": "Unterstützt Bilder",
 		"noImages": "Unterstützt keine Bilder",
diff --git a/webview-ui/src/i18n/locales/en/settings.json b/webview-ui/src/i18n/locales/en/settings.json
index b8e51afc50..2eca916034 100644
--- a/webview-ui/src/i18n/locales/en/settings.json
+++ b/webview-ui/src/i18n/locales/en/settings.json
@@ -519,6 +519,11 @@
 		"description": "Controls randomness in the model's responses.",
 		"rangeDescription": "Higher values make output more random, lower values make it more deterministic."
 	},
+	"seed": {
+		"useCustom": "Use custom seed",
+		"description": "Controls the deterministic nature of the model's responses. Leave blank for random.",
+		"label": "Enter a seed value"
+	},
 	"modelInfo": {
 		"supportsImages": "Supports images",
 		"noImages": "Does not support images",
diff --git a/webview-ui/src/i18n/locales/es/settings.json b/webview-ui/src/i18n/locales/es/settings.json
index db8b4736eb..bc04cd62a9 100644
--- a/webview-ui/src/i18n/locales/es/settings.json
+++ b/webview-ui/src/i18n/locales/es/settings.json
@@ -519,6 +519,11 @@
 		"description": "Controla la aleatoriedad en las respuestas del modelo.",
 		"rangeDescription": "Valores más altos hacen que la salida sea más aleatoria, valores más bajos la hacen más determinista."
 	},
+	"seed": {
+		"useCustom": "Usar semilla personalizada",
+		"description": "Controla la naturaleza determinista de las respuestas del modelo. Dejar en blanco para aleatorio.",
+		"label": "Introducir un valor de semilla"
+	},
 	"modelInfo": {
 		"supportsImages": "Soporta imágenes",
 		"noImages": "No soporta imágenes",
diff --git a/webview-ui/src/i18n/locales/fr/settings.json b/webview-ui/src/i18n/locales/fr/settings.json
index 0bf837accb..89175f6c2a 100644
--- a/webview-ui/src/i18n/locales/fr/settings.json
+++ b/webview-ui/src/i18n/locales/fr/settings.json
@@ -519,6 +519,11 @@
 		"description": "Contrôle l'aléatoire dans les réponses du modèle.",
 		"rangeDescription": "Des valeurs plus élevées rendent la sortie plus aléatoire, des valeurs plus basses la rendent plus déterministe."
 	},
+	"seed": {
+		"useCustom": "Utiliser une graine personnalisée",
+		"description": "Contrôle la nature déterministe des réponses du modèle. Laisser vide pour aléatoire.",
+		"label": "Entrez une valeur de graine"
+	},
 	"modelInfo": {
 		"supportsImages": "Prend en charge les images",
 		"noImages": "Ne prend pas en charge les images",
diff --git a/webview-ui/src/i18n/locales/hi/settings.json b/webview-ui/src/i18n/locales/hi/settings.json
index fec1b27007..163c41f2c8 100644
--- a/webview-ui/src/i18n/locales/hi/settings.json
+++ b/webview-ui/src/i18n/locales/hi/settings.json
@@ -519,6 +519,11 @@
 		"description": "मॉडल की प्रतिक्रियाओं में यादृच्छिकता को नियंत्रित करता है।",
 		"rangeDescription": "उच्च मान आउटपुट को अधिक यादृच्छिक बनाते हैं, निम्न मान इसे अधिक निर्धारित बनाते हैं।"
 	},
+	"seed": {
+		"useCustom": "कस्टम सीड का प्रयोग करें",
+		"description": "मॉडल की प्रतिक्रियाओं की déterministe प्रकृति को नियंत्रित करता है। यादृच्छिक के लिए खाली छोड़ दें।",
+		"label": "एक सीड मान दर्ज करें"
+	},
 	"modelInfo": {
 		"supportsImages": "छवियों का समर्थन करता है",
 		"noImages": "छवियों का समर्थन नहीं करता है",
diff --git a/webview-ui/src/i18n/locales/it/settings.json b/webview-ui/src/i18n/locales/it/settings.json
index fcb389a4a7..823b072a9e 100644
--- a/webview-ui/src/i18n/locales/it/settings.json
+++ b/webview-ui/src/i18n/locales/it/settings.json
@@ -519,6 +519,11 @@
 		"description": "Controlla la casualità nelle risposte del modello.",
 		"rangeDescription": "Valori più alti rendono l'output più casuale, valori più bassi lo rendono più deterministico."
 	},
+	"seed": {
+		"useCustom": "Usa seed personalizzato",
+		"description": "Controlla la natura deterministica delle risposte del modello. Lasciare vuoto per casuale.",
+		"label": "Inserisci un valore di seed"
+	},
 	"modelInfo": {
 		"supportsImages": "Supporta immagini",
 		"noImages": "Non supporta immagini",
diff --git a/webview-ui/src/i18n/locales/ja/settings.json b/webview-ui/src/i18n/locales/ja/settings.json
index eabd751308..6faaab3edb 100644
--- a/webview-ui/src/i18n/locales/ja/settings.json
+++ b/webview-ui/src/i18n/locales/ja/settings.json
@@ -519,6 +519,11 @@
 		"description": "モデルの応答のランダム性を制御します。",
 		"rangeDescription": "高い値は出力をよりランダムに、低い値はより決定論的にします。"
 	},
+	"seed": {
+		"useCustom": "カスタムシードを使用",
+		"description": "モデルの応答の決定性を制御します。ランダムの場合は空白のままにします。",
+		"label": "シード値を入力してください"
+	},
 	"modelInfo": {
 		"supportsImages": "画像をサポート",
 		"noImages": "画像をサポートしていません",
diff --git a/webview-ui/src/i18n/locales/ko/settings.json b/webview-ui/src/i18n/locales/ko/settings.json
index 68ca2a963c..6276746971 100644
--- a/webview-ui/src/i18n/locales/ko/settings.json
+++ b/webview-ui/src/i18n/locales/ko/settings.json
@@ -519,6 +519,11 @@
 		"description": "모델 응답의 무작위성을 제어합니다.",
 		"rangeDescription": "높은 값은 출력을 더 무작위하게, 낮은 값은 더 결정적으로 만듭니다."
 	},
+	"seed": {
+		"useCustom": "사용자 지정 시드 사용",
+		"description": "모델 응답의 결정적 특성을 제어합니다. 무작위의 경우 비워 둡니다.",
+		"label": "시드 값 입력"
+	},
 	"modelInfo": {
 		"supportsImages": "이미지 지원",
 		"noImages": "이미지 지원 안 함",
diff --git a/webview-ui/src/i18n/locales/nl/settings.json b/webview-ui/src/i18n/locales/nl/settings.json
index 996c0c673c..6548b35b47 100644
--- a/webview-ui/src/i18n/locales/nl/settings.json
+++ b/webview-ui/src/i18n/locales/nl/settings.json
@@ -519,6 +519,11 @@
 		"description": "Bepaalt de willekeurigheid in de antwoorden van het model.",
 		"rangeDescription": "Hogere waarden maken de output willekeuriger, lagere waarden maken deze deterministischer."
 	},
+	"seed": {
+		"useCustom": "Aangepaste seed gebruiken",
+		"description": "Bepaalt de deterministische aard van de antwoorden van het model. Laat leeg voor willekeurig.",
+		"label": "Voer een seed-waarde in"
+	},
 	"modelInfo": {
 		"supportsImages": "Ondersteunt afbeeldingen",
 		"noImages": "Ondersteunt geen afbeeldingen",
diff --git a/webview-ui/src/i18n/locales/pl/settings.json b/webview-ui/src/i18n/locales/pl/settings.json
index cf4421e00e..f13890c644 100644
--- a/webview-ui/src/i18n/locales/pl/settings.json
+++ b/webview-ui/src/i18n/locales/pl/settings.json
@@ -519,6 +519,11 @@
 		"description": "Kontroluje losowość w odpowiedziach modelu.",
 		"rangeDescription": "Wyższe wartości sprawiają, że wyjście jest bardziej losowe, niższe wartości czynią je bardziej deterministycznym."
 	},
+	"seed": {
+		"useCustom": "Użyj niestandardowego ziarna",
+		"description": "Kontroluje deterministyczną naturę odpowiedzi modelu. Pozostaw puste dla losowości.",
+		"label": "Wprowadź wartość ziarna"
+	},
 	"modelInfo": {
 		"supportsImages": "Obsługuje obrazy",
 		"noImages": "Nie obsługuje obrazów",
diff --git a/webview-ui/src/i18n/locales/pt-BR/settings.json b/webview-ui/src/i18n/locales/pt-BR/settings.json
index 229419dd23..86045e7d67 100644
--- a/webview-ui/src/i18n/locales/pt-BR/settings.json
+++ b/webview-ui/src/i18n/locales/pt-BR/settings.json
@@ -519,6 +519,11 @@
 		"description": "Controla a aleatoriedade nas respostas do modelo.",
 		"rangeDescription": "Valores mais altos tornam a saída mais aleatória, valores mais baixos a tornam mais determinística."
 	},
+	"seed": {
+		"useCustom": "Usar semente personalizada",
+		"description": "Controla a natureza determinística das respostas do modelo. Deixe em branco para aleatório.",
+		"label": "Insira um valor de semente"
+	},
 	"modelInfo": {
 		"supportsImages": "Suporta imagens",
 		"noImages": "Não suporta imagens",
diff --git a/webview-ui/src/i18n/locales/ru/settings.json b/webview-ui/src/i18n/locales/ru/settings.json
index dcce5e5b1a..0b4d44bcd3 100644
--- a/webview-ui/src/i18n/locales/ru/settings.json
+++ b/webview-ui/src/i18n/locales/ru/settings.json
@@ -519,6 +519,11 @@
 		"description": "Управляет случайностью ответов модели.",
 		"rangeDescription": "Более высокие значения делают ответы более случайными, низкие — более детерминированными."
 	},
+	"seed": {
+		"useCustom": "Использовать пользовательское начальное значение",
+		"description": "Контролирует детерминированность ответов модели. Оставьте пустым для случайного значения.",
+		"label": "Введите начальное значение"
+	},
 	"modelInfo": {
 		"supportsImages": "Поддерживает изображения",
 		"noImages": "Не поддерживает изображения",
diff --git a/webview-ui/src/i18n/locales/tr/settings.json b/webview-ui/src/i18n/locales/tr/settings.json
index f8f53ae21c..99dbf4c17e 100644
--- a/webview-ui/src/i18n/locales/tr/settings.json
+++ b/webview-ui/src/i18n/locales/tr/settings.json
@@ -519,6 +519,11 @@
 		"description": "Model yanıtlarındaki rastgeleliği kontrol eder.",
 		"rangeDescription": "Daha yüksek değerler çıktıyı daha rastgele yapar, daha düşük değerler daha deterministik hale getirir."
 	},
+	"seed": {
+		"useCustom": "Özel tohum kullan",
+		"description": "Modelin yanıtlarının deterministik doğasını kontrol eder. Rastgele için boş bırakın.",
+		"label": "Bir tohum değeri girin"
+	},
 	"modelInfo": {
 		"supportsImages": "Görüntüleri destekler",
 		"noImages": "Görüntüleri desteklemez",
diff --git a/webview-ui/src/i18n/locales/vi/settings.json b/webview-ui/src/i18n/locales/vi/settings.json
index edb2b386b2..cfd3a004f3 100644
--- a/webview-ui/src/i18n/locales/vi/settings.json
+++ b/webview-ui/src/i18n/locales/vi/settings.json
@@ -519,6 +519,11 @@
 		"description": "Kiểm soát tính ngẫu nhiên trong phản hồi của mô hình.",
 		"rangeDescription": "Giá trị cao hơn làm cho đầu ra ngẫu nhiên hơn, giá trị thấp hơn làm cho nó xác định hơn."
 	},
+	"seed": {
+		"useCustom": "Sử dụng hạt giống tùy chỉnh",
+		"description": "Kiểm soát tính xác định của các phản hồi của mô hình. Để trống cho ngẫu nhiên.",
+		"label": "Nhập giá trị hạt giống"
+	},
 	"modelInfo": {
 		"supportsImages": "Hỗ trợ hình ảnh",
 		"noImages": "Không hỗ trợ hình ảnh",
diff --git a/webview-ui/src/i18n/locales/zh-CN/settings.json b/webview-ui/src/i18n/locales/zh-CN/settings.json
index 51ae2269e4..d2ec046f85 100644
--- a/webview-ui/src/i18n/locales/zh-CN/settings.json
+++ b/webview-ui/src/i18n/locales/zh-CN/settings.json
@@ -519,6 +519,11 @@
 		"description": "控制模型响应的随机性",
 		"rangeDescription": "值越高回答越多样，值越低越保守"
 	},
+	"seed": {
+		"useCustom": "使用自定义种子",
+		"description": "控制模型响应的确定性。留空则随机。",
+		"label": "输入种子值"
+	},
 	"modelInfo": {
 		"supportsImages": "支持图像",
 		"noImages": "不支持图像",
diff --git a/webview-ui/src/i18n/locales/zh-TW/settings.json b/webview-ui/src/i18n/locales/zh-TW/settings.json
index 07544879cd..683a98e15d 100644
--- a/webview-ui/src/i18n/locales/zh-TW/settings.json
+++ b/webview-ui/src/i18n/locales/zh-TW/settings.json
@@ -519,6 +519,11 @@
 		"description": "控制模型回應的隨機性",
 		"rangeDescription": "較高值使輸出更隨機，較低值更確定"
 	},
+	"seed": {
+		"useCustom": "使用自訂種子",
+		"description": "控制模型回應的確定性。留空則隨機。",
+		"label": "輸入種子值"
+	},
 	"modelInfo": {
 		"supportsImages": "支援影像",
 		"noImages": "不支援影像",