diff --git a/packages/shared/src/contracts/model3d/image-to-model/Model3dImageToModelParams.ts b/packages/shared/src/contracts/model3d/image-to-model/Model3dImageToModelParams.ts
index 031f12a70..274ad169b 100644
--- a/packages/shared/src/contracts/model3d/image-to-model/Model3dImageToModelParams.ts
+++ b/packages/shared/src/contracts/model3d/image-to-model/Model3dImageToModelParams.ts
@@ -17,8 +17,8 @@ import type { Model3dTextureVersion } from '../common/Model3dTextureVersion';
 export type Model3dImageToModelParams = {
   model: Model3dModelVersion;
   enableImageAutofix?: boolean | null;
-  modelSeed?: number | null;
-  textureSeed?: number | null;
+  modelSeed?: bigint | null;
+  textureSeed?: bigint | null;
   texture?: boolean | null;
   pbr?: boolean | null;
   textureQuality?: Model3dTextureQuality | null;
diff --git a/packages/shared/src/contracts/model3d/multiview-to-model/Model3dMultiviewToModelRequest.ts b/packages/shared/src/contracts/model3d/multiview-to-model/Model3dMultiviewToModelRequest.ts
index 152def9bb..f9fc93903 100644
--- a/packages/shared/src/contracts/model3d/multiview-to-model/Model3dMultiviewToModelRequest.ts
+++ b/packages/shared/src/contracts/model3d/multiview-to-model/Model3dMultiviewToModelRequest.ts
@@ -12,8 +12,8 @@ import type { Model3dMultiviewInputs } from './Model3dMultiviewInputs';
 export type Model3dMultiviewToModelRequest = {
   inputs: Model3dMultiviewInputs;
   model: Model3dModelVersion;
-  modelSeed?: number | null;
-  textureSeed?: number | null;
+  modelSeed?: bigint | null;
+  textureSeed?: bigint | null;
   texture?: boolean | null;
   pbr?: boolean | null;
   textureQuality?: Model3dTextureQuality | null;
diff --git a/packages/shared/src/contracts/model3d/text-to-model/Model3dTextToModelParams.ts b/packages/shared/src/contracts/model3d/text-to-model/Model3dTextToModelParams.ts
index e8520db02..68f76b2f1 100644
--- a/packages/shared/src/contracts/model3d/text-to-model/Model3dTextToModelParams.ts
+++ b/packages/shared/src/contracts/model3d/text-to-model/Model3dTextToModelParams.ts
@@ -16,9 +16,9 @@ export type Model3dTextToModelParams = {
   prompt: string;
   model: Model3dModelVersion;
   negativePrompt?: string | null;
-  imageSeed?: number | null;
-  modelSeed?: number | null;
-  textureSeed?: number | null;
+  imageSeed?: bigint | null;
+  modelSeed?: bigint | null;
+  textureSeed?: bigint | null;
   texture?: boolean | null;
   pbr?: boolean | null;
   textureQuality?: Model3dTextureQuality | null;
diff --git a/server-rs/crates/shared-contracts/src/model3d/image_to_model/params.rs b/server-rs/crates/shared-contracts/src/model3d/image_to_model/params.rs
index 4e9464874..2780c45ea 100644
--- a/server-rs/crates/shared-contracts/src/model3d/image_to_model/params.rs
+++ b/server-rs/crates/shared-contracts/src/model3d/image_to_model/params.rs
@@ -19,10 +19,11 @@ pub struct Model3dImageToModelParams {
     pub model: Model3dModelVersion,
     #[ts(optional = nullable)]
     pub enable_image_autofix: Option<bool>,
-    #[ts(type = "number | null")]
+    // seed 是 i64，JS `number` 表示不了全部取值，因此按 bigint 导出，避免静默舍入。
+    #[ts(type = "bigint | null")]
     #[ts(optional = nullable)]
     pub model_seed: Option<i64>,
-    #[ts(type = "number | null")]
+    #[ts(type = "bigint | null")]
     #[ts(optional = nullable)]
     pub texture_seed: Option<i64>,
     #[ts(optional = nullable)]
diff --git a/server-rs/crates/shared-contracts/src/model3d/multiview_to_model/request.rs b/server-rs/crates/shared-contracts/src/model3d/multiview_to_model/request.rs
index 6250e6adc..5196df866 100644
--- a/server-rs/crates/shared-contracts/src/model3d/multiview_to_model/request.rs
+++ b/server-rs/crates/shared-contracts/src/model3d/multiview_to_model/request.rs
@@ -45,10 +45,11 @@ pub enum Model3dMultiviewInputs {
 pub struct Model3dMultiviewToModelRequest {
     pub inputs: Model3dMultiviewInputs,
     pub model: Model3dModelVersion,
-    #[ts(type = "number | null")]
+    // seed 是 i64，JS `number` 表示不了全部取值，因此按 bigint 导出，避免静默舍入。
+    #[ts(type = "bigint | null")]
     #[ts(optional = nullable)]
     pub model_seed: Option<i64>,
-    #[ts(type = "number | null")]
+    #[ts(type = "bigint | null")]
     #[ts(optional = nullable)]
     pub texture_seed: Option<i64>,
     #[ts(optional = nullable)]
diff --git a/server-rs/crates/shared-contracts/src/model3d/text_to_model/params.rs b/server-rs/crates/shared-contracts/src/model3d/text_to_model/params.rs
index 12d94b2f0..82abb7e24 100644
--- a/server-rs/crates/shared-contracts/src/model3d/text_to_model/params.rs
+++ b/server-rs/crates/shared-contracts/src/model3d/text_to_model/params.rs
@@ -19,13 +19,14 @@ pub struct Model3dTextToModelParams {
     pub model: Model3dModelVersion,
     #[ts(optional = nullable)]
     pub negative_prompt: Option<String>,
-    #[ts(type = "number | null")]
+    // seed 是 i64，JS `number` 表示不了全部取值，因此按 bigint 导出，避免静默舍入。
+    #[ts(type = "bigint | null")]
     #[ts(optional = nullable)]
     pub image_seed: Option<i64>,
-    #[ts(type = "number | null")]
+    #[ts(type = "bigint | null")]
     #[ts(optional = nullable)]
     pub model_seed: Option<i64>,
-    #[ts(type = "number | null")]
+    #[ts(type = "bigint | null")]
     #[ts(optional = nullable)]
     pub texture_seed: Option<i64>,
     #[ts(optional = nullable)]