diff --git a/backend/internal/service/model_capability.go b/backend/internal/service/model_capability.go
index e96dcdc87..2af034c2a 100644
--- a/backend/internal/service/model_capability.go
+++ b/backend/internal/service/model_capability.go
@@ -7,6 +7,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"unicode/utf8"
 
 	"infinite-canvas/backend/internal/model"
 )
@@ -593,6 +594,9 @@ func (s *Service) ValidateTaskCapability(input map[string]any) error {
 		return nil
 	}
 	if isWorkflowProviderInterface(taskInput.Config.InterfaceType) {
+		if err := validateWorkflowProviderPromptLength(taskInput); err != nil {
+			return err
+		}
 		return validateWorkflowProviderConfig(taskInput.Mode, taskInput.Config)
 	}
 	// 普通音频模型沿用主线的能力校验路径；当前专用能力表只覆盖图片和视频。
@@ -672,6 +676,12 @@ func applyFixedVideoResolution(input *canvasGenerationInput, profile *VideoCapab
 }
 
 func validateVideoTask(profile *VideoCapabilityConfig, input canvasGenerationInput) error {
+	if profile == nil {
+		return BadAuthRequest("当前视频模型能力参数无效")
+	}
+	if err := validateModelPromptLength("视频", input.Prompt, profile.References.PromptMaxChars); err != nil {
+		return err
+	}
 	if len(input.ReferenceImages) > profile.References.MaxImages || len(input.ReferenceVideos) > profile.References.MaxVideos || len(input.ReferenceAudios) > profile.References.MaxAudios {
 		return BadAuthRequest("参考素材数量超过当前模型限制")
 	}
@@ -767,6 +777,25 @@ func validateImageTask(profile *ImageCapabilityConfig, input canvasGenerationInp
 	return nil
 }
 
+func validateWorkflowProviderPromptLength(input canvasGenerationInput) error {
+	profile := input.Config.CapabilityConfig
+	if input.Mode != "video" || profile == nil || profile.Video == nil {
+		return nil
+	}
+	return validateModelPromptLength("视频", input.Prompt, profile.Video.References.PromptMaxChars)
+}
+
+func validateModelPromptLength(label string, prompt string, maxChars int) error {
+	if maxChars <= 0 {
+		return nil
+	}
+	actualChars := utf8.RuneCountInString(prompt)
+	if actualChars <= maxChars {
+		return nil
+	}
+	return BadAuthRequest(fmt.Sprintf("当前%s模型提示词最多 %d 个字符，完整提示词为 %d 个字符。系统不会自动截断，请精简当前输入、连线内容或技能上下文后重试", label, maxChars, actualChars))
+}
+
 func validateGPTImage2CustomSize(value string) error {
 	value = strings.ToLower(strings.TrimSpace(strings.ReplaceAll(value, "×", "x")))
 	if value == "" || value == "auto" {
diff --git a/backend/internal/service/model_capability_test.go b/backend/internal/service/model_capability_test.go
index 5ce98f587..1efa0f715 100644
--- a/backend/internal/service/model_capability_test.go
+++ b/backend/internal/service/model_capability_test.go
@@ -37,6 +37,39 @@ func TestValidateImageTaskDoesNotApplyQualityPromptLimitToGrokLite(t *testing.T)
 	}
 }
 
+func TestValidateVideoTaskRejectsPromptAboveCapabilityLimit(t *testing.T) {
+	profile := DefaultModelCapabilityConfigForModel("autodl-comfyui", "MiniMax H3").Video
+	profile.References.PromptMaxChars = 10_000
+	input := canvasGenerationInput{
+		Mode:   "video",
+		Prompt: strings.Repeat("镜", 23_142),
+		Config: providerConfig{Model: "MiniMax H3", VideoSeconds: "15", Size: "16:9", VQuality: "768p横"},
+	}
+
+	err := validateVideoTask(profile, input)
+	if err == nil || !strings.Contains(err.Error(), "最多 10000 个字符") || !strings.Contains(err.Error(), "23142 个字符") || !strings.Contains(err.Error(), "不会自动截断") {
+		t.Fatalf("validateVideoTask() error = %v", err)
+	}
+}
+
+func TestValidateTaskCapabilityRejectsWorkflowPromptAboveConfiguredLimit(t *testing.T) {
+	profile := DefaultModelCapabilityConfigForModel("runninghub-workflow-video", "workflow-video")
+	profile.Video.References.PromptMaxChars = 10_000
+	input := map[string]any{
+		"mode":   "video",
+		"prompt": strings.Repeat("镜", 10_001),
+		"config": map[string]any{
+			"interfaceType":    "runninghub-workflow-video",
+			"capabilityConfig": profile,
+		},
+	}
+
+	err := (&Service{}).ValidateTaskCapability(input)
+	if err == nil || !strings.Contains(err.Error(), "完整提示词为 10001 个字符") {
+		t.Fatalf("ValidateTaskCapability() error = %v", err)
+	}
+}
+
 func TestValidateImageTaskEnforcesGPTImage2CustomSizeLimits(t *testing.T) {
 	profile := DefaultImageCapabilityConfig("openai-image", "gpt-image-2")
 	profile.Size.AllowCustom = true
diff --git a/backend/internal/service/project_workflow.go b/backend/internal/service/project_workflow.go
index 2c1e93699..ed0281ca1 100644
--- a/backend/internal/service/project_workflow.go
+++ b/backend/internal/service/project_workflow.go
@@ -1,6 +1,8 @@
 package service
 
 import (
+	"crypto/sha256"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"strings"
@@ -590,8 +592,8 @@ func (s *Service) ensureGeneratedProjectAsset(task model.Task, projectID string,
 		return "", err
 	}
 	now := time.Now()
-	assetID := "workflow-asset-" + task.ID
-	versionID := "workflow-version-" + task.ID
+	assetID := workflowGeneratedEntityID("asset", task.ID)
+	versionID := workflowGeneratedEntityID("version", task.ID)
 	label := "图片"
 	if mediaType == "video" {
 		label = "视频"
@@ -627,6 +629,12 @@ func (s *Service) ensureGeneratedProjectAsset(task model.Task, projectID string,
 	return versionID, nil
 }
 
+// 工作流产物重试必须复用同一实体 ID，同时需要满足素材版本及外键的 varchar(36) 约束。
+func workflowGeneratedEntityID(namespace string, taskID string) string {
+	sum := sha256.Sum256([]byte(strings.TrimSpace(namespace) + ":" + strings.TrimSpace(taskID)))
+	return hex.EncodeToString(sum[:16])
+}
+
 func validWorkflowStepStatus(status model.WorkflowStepStatus) bool {
 	switch status {
 	case model.WorkflowStepStatusPending, model.WorkflowStepStatusReady, model.WorkflowStepStatusRunning, model.WorkflowStepStatusReview, model.WorkflowStepStatusCompleted, model.WorkflowStepStatusFailed, model.WorkflowStepStatusSkipped:
diff --git a/backend/internal/service/project_workflow_v2_test.go b/backend/internal/service/project_workflow_v2_test.go
index 07004ef4e..e712a5d19 100644
--- a/backend/internal/service/project_workflow_v2_test.go
+++ b/backend/internal/service/project_workflow_v2_test.go
@@ -59,7 +59,7 @@ func TestRegisterTaskOutputFromTaskPersistsMediaAssetAndArtifactIdempotently(t *
 	if err := db.Create(&resource).Error; err != nil {
 		t.Fatal(err)
 	}
-	task := model.Task{ID: "workflow-video-task-1", UserID: "user-1", ProjectID: project.ID, Type: "canvas_video", Status: model.TaskStatusSucceeded,
+	task := model.Task{ID: "ac745990450a86d3365eb92ec26f378e", UserID: "user-1", ProjectID: project.ID, Type: "canvas_video", Status: model.TaskStatusSucceeded,
 		InputJSON:  `{"metadata":{"workflowStepId":"` + videoStep.ID + `","domainProjectId":"` + project.ID + `","unitId":"` + unit.ID + `","shotId":"` + shot.ID + `","shotRevisionId":"` + submittedRevisionID + `","artifactType":"video","role":"output","artifactMetadata":{"model":"MiniMax-H3"}}}`,
 		ResultJSON: `{"mode":"video","video":{"resourceId":"resource-video-1","storageKey":"resource:resource-video-1","mimeType":"video/mp4"}}`, CreatedAt: now, UpdatedAt: now}
 	if err := db.Create(&task).Error; err != nil {
@@ -71,17 +71,38 @@ func TestRegisterTaskOutputFromTaskPersistsMediaAssetAndArtifactIdempotently(t *
 	if err := service.RegisterTaskOutputFromTask(task); err != nil {
 		t.Fatal(err)
 	}
-	for table, query := range map[string]string{
-		"assets":                "id = 'workflow-asset-workflow-video-task-1'",
-		"project_asset_links":   "asset_id = 'workflow-asset-workflow-video-task-1'",
-		"asset_representations": "task_id = 'workflow-video-task-1' AND role = 'output'",
-		"shot_artifacts":        "task_id = 'workflow-video-task-1' AND type = 'video'",
-	} {
+	assetID := workflowGeneratedEntityID("asset", task.ID)
+	versionID := workflowGeneratedEntityID("version", task.ID)
+	checks := []struct {
+		table string
+		where string
+		value string
+	}{
+		{table: "assets", where: "id = ?", value: assetID},
+		{table: "project_asset_links", where: "asset_id = ?", value: assetID},
+		{table: "asset_representations", where: "task_id = ? AND role = 'output'", value: task.ID},
+		{table: "shot_artifacts", where: "task_id = ? AND type = 'video'", value: task.ID},
+	}
+	for _, check := range checks {
 		var count int64
-		if err := db.Table(table).Where(query).Count(&count).Error; err != nil || count != 1 {
-			t.Fatalf("%s count = %d, error = %v", table, count, err)
+		if err := db.Table(check.table).Where(check.where, check.value).Count(&count).Error; err != nil || count != 1 {
+			t.Fatalf("%s count = %d, error = %v", check.table, count, err)
 		}
 	}
+	var asset model.Asset
+	if err := db.First(&asset, "id = ?", assetID).Error; err != nil {
+		t.Fatal(err)
+	}
+	if len(asset.PrimaryVersionID) > 36 || asset.PrimaryVersionID != versionID {
+		t.Fatalf("primary version ID = %q, want %q with at most 36 characters", asset.PrimaryVersionID, versionID)
+	}
+	var version model.AssetVersion
+	if err := db.First(&version, "id = ?", versionID).Error; err != nil {
+		t.Fatal(err)
+	}
+	if len(version.ID) > 36 {
+		t.Fatalf("asset version ID length = %d, want at most 36", len(version.ID))
+	}
 	var artifact model.ShotArtifact
 	if err := db.First(&artifact, "task_id = ?", task.ID).Error; err != nil {
 		t.Fatal(err)
diff --git a/backend/internal/service/provider.go b/backend/internal/service/provider.go
index fb5fa3006..5be30a771 100644
--- a/backend/internal/service/provider.go
+++ b/backend/internal/service/provider.go
@@ -344,6 +344,9 @@ func (s *Service) processCanvasGenerationTask(ctx context.Context, userID string
 		if err := s.RequireWorkflowPluginForInterface(input.Config.InterfaceType); err != nil {
 			return nil, err
 		}
+		if err := validateWorkflowProviderPromptLength(input); err != nil {
+			return nil, err
+		}
 		if err := validateWorkflowProviderConfig(input.Mode, input.Config); err != nil {
 			return nil, err
 		}
@@ -4950,8 +4953,7 @@ func doJSON(req *http.Request, target interface{}) error {
 		}
 	}
 	if payload, ok := target.(*map[string]interface{}); ok {
-		if code, ok := (*payload)["code"].(float64); ok && code != 0 {
-			rawMessage := stringField(*payload, "msg")
+		if _, rawMessage, failed := providerPayloadBusinessFailure(*payload); failed {
 			return providerPayloadError{raw: rawMessage, message: providerPayloadErrorMessage(rawMessage)}
 		}
 		if errValue, ok := (*payload)["error"].(map[string]interface{}); ok && stringField(errValue, "message") != "" {
@@ -5138,12 +5140,16 @@ func recordProviderRequest(req *http.Request, startedAt time.Time, statusCode in
 	if requestErr != nil || statusCode < 200 || statusCode >= 300 {
 		status = model.ApiCallStatusFailed
 		errorCode, errorText = providerRequestErrorDetails(requestErr)
+	} else if businessCode, businessMessage, failed := providerResponseBusinessFailure(responseBody); failed {
+		status = model.ApiCallStatusFailed
+		errorCode = businessCode
+		errorText = businessMessage
 	}
 	requestKind := providerRequestKind(req.Method, req.URL.Path)
 	if metadata.RequestKind != "" {
 		requestKind = metadata.RequestKind
 	}
-	if requestErr == nil && statusCode >= 200 && statusCode < 300 && (requestKind == "create" || requestKind == "poll") && (metadata.Capability == "image" || metadata.Capability == "video") {
+	if status == model.ApiCallStatusSucceeded && (requestKind == "create" || requestKind == "poll") && (metadata.Capability == "image" || metadata.Capability == "video") {
 		metadata.Service.syncProviderTaskProgress(metadata.TaskID, responseBody)
 	}
 	apiFormat := "openai"
diff --git a/backend/internal/service/provider_error.go b/backend/internal/service/provider_error.go
index 9ecfdb568..bbd03b9ce 100644
--- a/backend/internal/service/provider_error.go
+++ b/backend/internal/service/provider_error.go
@@ -1,6 +1,7 @@
 package service
 
 import (
+	"encoding/json"
 	"fmt"
 	"strings"
 )
@@ -27,11 +28,49 @@ func providerFailureDetails(payload map[string]any) (string, string) {
 		}
 		if message == "" {
 			message = strings.TrimSpace(stringField(candidate, "message"))
+			if message == "" {
+				message = strings.TrimSpace(stringField(candidate, "msg"))
+			}
 		}
 	}
 	return code, truncateRunes(message, 500)
 }
 
+func providerResponseBusinessFailure(responseBody []byte) (string, string, bool) {
+	if len(responseBody) == 0 {
+		return "", "", false
+	}
+	var payload map[string]any
+	if json.Unmarshal(responseBody, &payload) != nil {
+		return "", "", false
+	}
+	return providerPayloadBusinessFailure(payload)
+}
+
+func providerPayloadBusinessFailure(payload map[string]any) (string, string, bool) {
+	if errorValue, ok := payload["error"].(map[string]any); ok {
+		code, message := providerFailureDetails(map[string]any{"error": errorValue})
+		if code != "" || message != "" {
+			return code, message, true
+		}
+	}
+	if !providerBusinessCodeFailed(payload["code"]) {
+		return "", "", false
+	}
+	code, message := providerFailureDetails(payload)
+	return code, message, true
+}
+
+func providerBusinessCodeFailed(value any) bool {
+	code := strings.ToLower(strings.TrimSpace(fmt.Sprint(value)))
+	switch code {
+	case "", "0", "success", "succeeded", "ok", "<nil>":
+		return false
+	default:
+		return true
+	}
+}
+
 func normalizedProviderErrorCode(value any) string {
 	var code string
 	switch current := value.(type) {
diff --git a/backend/internal/service/provider_error_test.go b/backend/internal/service/provider_error_test.go
index 2075c6691..b9ad47b15 100644
--- a/backend/internal/service/provider_error_test.go
+++ b/backend/internal/service/provider_error_test.go
@@ -42,3 +42,20 @@ func TestContentModerationFailureRequiresExactProviderCode(t *testing.T) {
 		t.Fatal("generic HTTP 400 must remain retryable")
 	}
 }
+
+func TestProviderPayloadBusinessFailureRecognizesStringErrorCode(t *testing.T) {
+	code, message, failed := providerPayloadBusinessFailure(map[string]any{
+		"code": "RequestParameterIsWrong",
+		"data": nil,
+		"msg":  "参数: prompt 的长度: 23142 大于最大长度 10000",
+	})
+	if !failed || code != "RequestParameterIsWrong" || message != "参数: prompt 的长度: 23142 大于最大长度 10000" {
+		t.Fatalf("business failure = (%q, %q, %v)", code, message, failed)
+	}
+}
+
+func TestProviderPayloadBusinessFailureAcceptsStringSuccessCode(t *testing.T) {
+	if code, message, failed := providerPayloadBusinessFailure(map[string]any{"code": "Success", "data": map[string]any{"task_id": "task-1"}}); failed {
+		t.Fatalf("success payload was marked failed: (%q, %q)", code, message)
+	}
+}
diff --git a/web/src/lib/model-selection.ts b/web/src/lib/model-selection.ts
index e4d48ff3a..45c34bc94 100644
--- a/web/src/lib/model-selection.ts
+++ b/web/src/lib/model-selection.ts
@@ -101,6 +101,19 @@ export function modelCompatibilityError(config: AiConfig, model: string, require
     return input.imageCount > 0 || input.videoCount > 0 || input.audioCount > 0 ? "音频模型只接受文本或单个角色卡输入" : "";
 }
 
+export function modelPromptLengthError(config: AiConfig, model: string, capability: ModelCapability, prompt: string) {
+    const channel = resolveModelChannel(config, model);
+    const configuredProfile = channel.modelCosts?.find((item) => item.model === modelOptionName(model))?.capabilityConfig;
+    if (!configuredProfile) return "";
+    const profile = modelCapabilityConfigFor(config, model);
+    const maxChars = capability === "text" ? profile.text?.references.promptMaxChars : capability === "image" ? profile.image?.references.promptMaxChars : capability === "video" ? profile.video?.references.promptMaxChars : undefined;
+    if (!maxChars || maxChars <= 0) return "";
+    const actualChars = Array.from(prompt).length;
+    if (actualChars <= maxChars) return "";
+    const label = capability === "text" ? "文本" : capability === "image" ? "图片" : "视频";
+    return `当前${label}模型提示词最多 ${maxChars} 个字符，完整提示词为 ${actualChars} 个字符。系统不会自动截断，请精简当前输入、连线内容或技能上下文后重试`;
+}
+
 export function modelRequestOptions(config: AiConfig, capability: ModelCapability) {
     switch (capability) {
         case "image":
diff --git a/web/src/pages/canvas/use-canvas-generation-executor.ts b/web/src/pages/canvas/use-canvas-generation-executor.ts
index 61cac6c84..c0375148f 100644
--- a/web/src/pages/canvas/use-canvas-generation-executor.ts
+++ b/web/src/pages/canvas/use-canvas-generation-executor.ts
@@ -9,7 +9,7 @@ import { isGenerationTaskCapacityError } from "@/lib/canvas/canvas-generation-ba
 import { buildPortraitTexturePrompt } from "@/lib/canvas/canvas-portrait-texture";
 import { resolveCanvasStyleExecution } from "@/lib/canvas/canvas-style-execution";
 import { generationErrorMessage, generationFailureMetadata } from "@/lib/generation-error";
-import { modelCompatibilityError, modelGroupReferenceLimits, modelRequestOptions, type ModelRequirements } from "@/lib/model-selection";
+import { modelCompatibilityError, modelGroupReferenceLimits, modelPromptLengthError, modelRequestOptions, type ModelRequirements } from "@/lib/model-selection";
 import { navigateToSettings } from "@/lib/settings-navigation";
 import type { Skill } from "@/services/api/skills";
 import { skillRuntime } from "@/services/skill-runtime";
@@ -185,6 +185,11 @@ export function useCanvasGenerationExecutor({
                             return;
                         }
                     }
+                    const promptLengthError = mode === "video" ? modelPromptLengthError(generationConfig, generationConfig.model, mode, effectivePrompt) : "";
+                    if (promptLengthError) {
+                        message.error(promptLengthError);
+                        return;
+                    }
                     const generationContext = { ...rawGenerationContext, prompt: effectivePrompt };
                     if (mode === "audio" && generationContext.characterReferences.length) {
                         if (generationContext.characterReferences.length !== 1) {
diff --git a/web/test/canvas-model-policy.test.ts b/web/test/canvas-model-policy.test.ts
index 7afdc2074..829f3f43c 100644
--- a/web/test/canvas-model-policy.test.ts
+++ b/web/test/canvas-model-policy.test.ts
@@ -3,7 +3,7 @@ import { describe, expect, test } from "bun:test";
 import { canvasConnectionError } from "../src/lib/canvas/canvas-connection-policy";
 import { assertCanvasImageReferenceLimit, buildGenerationConfig, canvasImageReferenceLimitError, resolveCanvasGenerationModel } from "../src/lib/canvas/canvas-project-generation";
 import { defaultModelCapabilityConfig } from "../src/lib/model-capabilities";
-import { groupModelsByDisplayName, inferVideoOperation, modelCompatibilityError, modelGroupReferenceLimits, resolveCompatibleModel, resolveModelGenerationDefaults } from "../src/lib/model-selection";
+import { groupModelsByDisplayName, inferVideoOperation, modelCompatibilityError, modelGroupReferenceLimits, modelPromptLengthError, resolveCompatibleModel, resolveModelGenerationDefaults } from "../src/lib/model-selection";
 import { defaultConfig, normalizeModelOptionValue, type AiConfig, type ModelChannel } from "../src/stores/use-config-store";
 import { CanvasNodeType, type CanvasConnection, type CanvasNodeData } from "../src/types/canvas";
 
@@ -53,6 +53,18 @@ function node(id: string, type: CanvasNodeType, generationMode?: "image" | "vide
 }
 
 describe("逻辑模型选择", () => {
+    test("技能上下文展开后按最终视频模型字符上限拒绝提交", () => {
+        const config = policyConfig();
+        const model = config.videoModels[0]!;
+        config.channels[0]!.modelCosts![0]!.capabilityConfig!.video!.references.promptMaxChars = 10_000;
+
+        const error = modelPromptLengthError(config, model, "video", "镜".repeat(23_142));
+
+        expect(error).toContain("最多 10000 个字符");
+        expect(error).toContain("完整提示词为 23142 个字符");
+        expect(error).toContain("不会自动截断");
+    });
+
     test("图片逻辑模型忽略全局视频时长，不应显示为不支持当前时长", () => {
         const model = "platform::gpt-image-2";
         const channel: ModelChannel = {