diff --git a/apps/api/internal/runner/pricing.go b/apps/api/internal/runner/pricing.go
index 6c01387..f2c4fde 100644
--- a/apps/api/internal/runner/pricing.go
+++ b/apps/api/internal/runner/pricing.go
@@ -82,19 +82,23 @@ func (s *Service) billings(ctx context.Context, user *auth.User, kind string, bo
 		resource = "video"
 		unit = "5s_video"
 		baseKey = "videoBase"
-		duration := requestDurationSeconds(body)
+		duration, durationSource := billingDurationSeconds(body, response)
+		audioEnabled, audioSource := billingAudioEnabled(body, response)
 		durationUnits := math.Max(1, math.Ceil(duration/5))
 		amount := float64(count) *
 			durationUnits *
 			resourcePrice(config, resource, baseKey, "basePrice") *
 			resourceWeight(config, resource, "resolutionWeights", firstNonEmptyString(stringFromMap(body, "resolution"), stringFromMap(body, "size"))) *
-			resourceWeight(config, resource, "audioWeights", boolWeightKey(boolishValue(body["audio"]))) *
+			resourceWeight(config, resource, "audioWeights", boolWeightKey(audioEnabled)) *
 			resourceWeight(config, resource, "referenceVideoWeights", boolWeightKey(requestHasReferenceVideo(body))) *
-			resourceWeight(config, resource, "voiceSpecifiedWeights", boolWeightKey(requestHasVoiceID(body))) *
+			resourceWeight(config, resource, "voiceSpecifiedWeights", boolWeightKey(requestHasVoiceID(body, audioEnabled))) *
 			discount
 		return []any{billingLineWithDetails(candidate, resource, unit, count*int(durationUnits), roundPrice(amount), discount, simulated, map[string]any{
 			"count":             count,
+			"audio":             audioEnabled,
+			"audioSource":       audioSource,
 			"durationSeconds":   duration,
+			"durationSource":    durationSource,
 			"durationUnit":      "5s",
 			"durationUnitCount": durationUnits,
 		})}
@@ -345,6 +349,54 @@ func requestDurationSeconds(body map[string]any) float64 {
 	return 5
 }
 
+func billingDurationSeconds(body map[string]any, response clients.Response) (float64, string) {
+	if duration, ok := generatedVideoDurationSeconds(response.Result); ok {
+		return duration, "generated_video"
+	}
+	return requestDurationSeconds(body), "preprocessed_request"
+}
+
+func generatedVideoDurationSeconds(result map[string]any) (float64, bool) {
+	data, _ := result["data"].([]any)
+	for _, raw := range data {
+		item, _ := raw.(map[string]any)
+		if len(item) == 0 {
+			continue
+		}
+		duration := floatFromAny(item["duration"])
+		if duration <= 0 {
+			continue
+		}
+		rounded := math.Round(duration)
+		if rounded <= 0 {
+			rounded = 1
+		}
+		return rounded, true
+	}
+	return 0, false
+}
+
+func billingAudioEnabled(body map[string]any, response clients.Response) (bool, string) {
+	if value, ok := generatedVideoHasAudio(response.Result); ok {
+		return value, "generated_video"
+	}
+	return boolishValue(body["audio"]), "preprocessed_request"
+}
+
+func generatedVideoHasAudio(result map[string]any) (bool, bool) {
+	data, _ := result["data"].([]any)
+	for _, raw := range data {
+		item, _ := raw.(map[string]any)
+		if len(item) == 0 {
+			continue
+		}
+		if value, ok := boolishOptional(firstPresentValue(item, "has_audio", "hasAudio")); ok {
+			return value, true
+		}
+	}
+	return false, false
+}
+
 func requestHasReferenceVideo(body map[string]any) bool {
 	if hasNonEmptyArray(body["video_list"]) || hasNonEmptyArray(body["videoList"]) {
 		return true
@@ -367,8 +419,8 @@ func requestHasReferenceVideo(body map[string]any) bool {
 	return false
 }
 
-func requestHasVoiceID(body map[string]any) bool {
-	return boolishValue(body["audio"]) && firstNonEmptyStringValue(body, "voice_id", "voiceId") != ""
+func requestHasVoiceID(body map[string]any, audioEnabled bool) bool {
+	return audioEnabled && firstNonEmptyStringValue(body, "voice_id", "voiceId") != ""
 }
 
 func boolWeightKey(value bool) string {
@@ -379,25 +431,38 @@ func boolWeightKey(value bool) string {
 }
 
 func boolishValue(value any) bool {
+	result, _ := boolishOptional(value)
+	return result
+}
+
+func boolishOptional(value any) (bool, bool) {
 	switch typed := value.(type) {
 	case bool:
-		return typed
+		return typed, true
 	case string:
 		switch strings.ToLower(strings.TrimSpace(typed)) {
 		case "true", "1", "yes", "on":
-			return true
-		default:
-			return false
+			return true, true
+		case "false", "0", "no", "off":
+			return false, true
 		}
 	case int:
-		return typed != 0
+		return typed != 0, true
 	case int64:
-		return typed != 0
+		return typed != 0, true
 	case float64:
-		return typed != 0
-	default:
-		return false
+		return typed != 0, true
 	}
+	return false, false
+}
+
+func firstPresentValue(record map[string]any, keys ...string) any {
+	for _, key := range keys {
+		if value, ok := record[key]; ok {
+			return value
+		}
+	}
+	return nil
 }
 
 func hasNonEmptyArray(value any) bool {
diff --git a/apps/api/internal/runner/pricing_test.go b/apps/api/internal/runner/pricing_test.go
index 45280ea..43b0c74 100644
--- a/apps/api/internal/runner/pricing_test.go
+++ b/apps/api/internal/runner/pricing_test.go
@@ -76,6 +76,100 @@ func TestVideoBillingEstimateUsesFiveSecondUnitsAndDynamicWeights(t *testing.T)
 	if got, want := line["quantity"], 3; got != want {
 		t.Fatalf("video quantity = %v, want %v", got, want)
 	}
+	if got, want := line["durationSource"], "preprocessed_request"; got != want {
+		t.Fatalf("video duration source = %v, want %v", got, want)
+	}
+	if got, want := line["audioSource"], "preprocessed_request"; got != want {
+		t.Fatalf("video audio source = %v, want %v", got, want)
+	}
+}
+
+func TestVideoBillingPrefersGeneratedDuration(t *testing.T) {
+	service := &Service{}
+	candidate := store.RuntimeModelCandidate{
+		ModelName: "video-model",
+		BaseBillingConfig: map[string]any{
+			"video": map[string]any{"basePrice": 100},
+		},
+	}
+
+	items := service.billings(context.Background(), nil, "videos.generations", map[string]any{
+		"duration":   12,
+		"resolution": "720p",
+	}, candidate, clients.Response{
+		Result: map[string]any{
+			"data": []any{map[string]any{"type": "video", "duration": 6.6}},
+		},
+	}, false)
+
+	line := firstBillingLine(t, items)
+	if got, want := floatFromAny(line["durationSeconds"]), 7.0; got != want {
+		t.Fatalf("video generated duration = %v, want %v", got, want)
+	}
+	if got, want := floatFromAny(line["durationUnitCount"]), 2.0; got != want {
+		t.Fatalf("video generated duration units = %v, want %v", got, want)
+	}
+	if got, want := floatFromAny(line["amount"]), 200.0; got != want {
+		t.Fatalf("video generated duration amount = %v, want %v", got, want)
+	}
+	if got, want := line["durationSource"], "generated_video"; got != want {
+		t.Fatalf("video duration source = %v, want %v", got, want)
+	}
+}
+
+func TestVideoBillingPrefersGeneratedAudio(t *testing.T) {
+	service := &Service{}
+	candidate := store.RuntimeModelCandidate{
+		ModelName: "video-model",
+		BaseBillingConfig: map[string]any{
+			"video": map[string]any{
+				"basePrice":             100,
+				"audioWeights":          map[string]any{"true": 2, "false": 0.5},
+				"voiceSpecifiedWeights": map[string]any{"true": 4},
+			},
+		},
+	}
+
+	items := service.billings(context.Background(), nil, "videos.generations", map[string]any{
+		"audio":    false,
+		"duration": 5,
+	}, candidate, clients.Response{
+		Result: map[string]any{
+			"data": []any{map[string]any{"type": "video", "has_audio": true}},
+		},
+	}, false)
+
+	line := firstBillingLine(t, items)
+	if got, want := floatFromAny(line["amount"]), 200.0; got != want {
+		t.Fatalf("video generated audio amount = %v, want %v", got, want)
+	}
+	if got, want := line["audio"], true; got != want {
+		t.Fatalf("video generated audio = %v, want %v", got, want)
+	}
+	if got, want := line["audioSource"], "generated_video"; got != want {
+		t.Fatalf("video audio source = %v, want %v", got, want)
+	}
+
+	items = service.billings(context.Background(), nil, "videos.generations", map[string]any{
+		"audio":    true,
+		"duration": 5,
+		"voice_id": "voice-a",
+	}, candidate, clients.Response{
+		Result: map[string]any{
+			"data": []any{map[string]any{"type": "video", "hasAudio": false}},
+		},
+	}, false)
+
+	line = firstBillingLine(t, items)
+	if got, want := floatFromAny(line["amount"]), 50.0; got != want {
+		t.Fatalf("video generated no-audio amount = %v, want %v", got, want)
+	}
+	if got, want := line["audio"], false; got != want {
+		t.Fatalf("video generated no-audio = %v, want %v", got, want)
+	}
+	if got, want := line["audioSource"], "generated_video"; got != want {
+		t.Fatalf("video no-audio source = %v, want %v", got, want)
+	}
 }
 
 func TestVideoBillingEstimateSupportsServerMainStyleDynamicKeys(t *testing.T) {
diff --git a/apps/api/internal/runner/service.go b/apps/api/internal/runner/service.go
index 36e485c..85d4be3 100644
--- a/apps/api/internal/runner/service.go
+++ b/apps/api/internal/runner/service.go
@@ -616,6 +616,7 @@ func (s *Service) runCandidate(ctx context.Context, task store.GatewayTask, user
 		return clients.Response{}, err
 	}
 	response.Result = uploadedResult
+	response.Result = s.enrichGeneratedVideoMetadata(ctx, task.Kind, response.Result)
 	for _, progress := range response.Progress {
 		if err := s.emit(ctx, task.ID, "task.progress", "running", progress.Phase, progress.Progress, progress.Message, progress.Payload, simulated); err != nil {
 			return clients.Response{}, fmt.Errorf("emit task progress: %w", err)
diff --git a/apps/api/internal/runner/video_duration.go b/apps/api/internal/runner/video_duration.go
new file mode 100644
index 0000000..d16c54c
--- /dev/null
+++ b/apps/api/internal/runner/video_duration.go
@@ -0,0 +1,144 @@
+package runner
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"math"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const generatedVideoMetadataProbeTimeout = 8 * time.Second
+
+type generatedVideoMetadata struct {
+	Duration      float64
+	HasAudio      bool
+	HasAudioKnown bool
+}
+
+type ffprobeVideoMetadata struct {
+	Format struct {
+		Duration string `json:"duration"`
+	} `json:"format"`
+	Streams []struct {
+		CodecType string `json:"codec_type"`
+	} `json:"streams"`
+}
+
+func (s *Service) enrichGeneratedVideoMetadata(ctx context.Context, taskKind string, result map[string]any) map[string]any {
+	if taskKind != "videos.generations" {
+		return result
+	}
+	data, _ := result["data"].([]any)
+	if len(data) == 0 {
+		return result
+	}
+	for _, raw := range data {
+		item, _ := raw.(map[string]any)
+		if len(item) == 0 || !isGeneratedVideoItem(item) {
+			continue
+		}
+		needsDuration := floatFromAny(item["duration"]) <= 0
+		_, hasAudioMetadata := boolishOptional(firstPresentValue(item, "has_audio", "hasAudio"))
+		if !needsDuration && hasAudioMetadata {
+			continue
+		}
+		urlValue := firstNonEmptyStringValue(item, "video_url", "videoUrl", "url")
+		if urlValue == "" {
+			continue
+		}
+		metadata, err := s.probeVideoMetadata(ctx, urlValue)
+		if err != nil {
+			if s.logger != nil {
+				s.logger.Debug("probe generated video metadata failed", "url", trimForLog(urlValue), "error", err)
+			}
+			continue
+		}
+		if needsDuration && metadata.Duration > 0 {
+			item["duration"] = metadata.Duration
+		}
+		if !hasAudioMetadata && metadata.HasAudioKnown {
+			item["has_audio"] = metadata.HasAudio
+		}
+	}
+	return result
+}
+
+func isGeneratedVideoItem(item map[string]any) bool {
+	itemType := strings.TrimSpace(stringFromAny(item["type"]))
+	if itemType == "video" {
+		return true
+	}
+	if firstNonEmptyStringValue(item, "video_url", "videoUrl") != "" {
+		return true
+	}
+	urlValue := strings.ToLower(firstNonEmptyStringValue(item, "url"))
+	return strings.Contains(urlValue, ".mp4") ||
+		strings.Contains(urlValue, ".mov") ||
+		strings.Contains(urlValue, ".webm") ||
+		strings.Contains(urlValue, ".m3u8")
+}
+
+func (s *Service) probeVideoMetadata(ctx context.Context, rawURL string) (generatedVideoMetadata, error) {
+	if _, err := exec.LookPath("ffprobe"); err != nil {
+		return generatedVideoMetadata{}, err
+	}
+	probeURL := rawURL
+	if s != nil {
+		if resolved, err := s.generatedAssetFetchURL(rawURL); err == nil && strings.TrimSpace(resolved) != "" {
+			probeURL = resolved
+		}
+	}
+	probeCtx, cancel := context.WithTimeout(ctx, generatedVideoMetadataProbeTimeout)
+	defer cancel()
+	cmd := exec.CommandContext(
+		probeCtx,
+		"ffprobe",
+		"-v", "error",
+		"-show_entries", "format=duration:stream=codec_type",
+		"-of", "json",
+		probeURL,
+	)
+	output, err := cmd.Output()
+	if err != nil {
+		return generatedVideoMetadata{}, err
+	}
+	var probed ffprobeVideoMetadata
+	if err := json.Unmarshal(output, &probed); err != nil {
+		return generatedVideoMetadata{}, err
+	}
+	metadata := generatedVideoMetadata{}
+	if durationText := strings.TrimSpace(probed.Format.Duration); durationText != "" {
+		if duration, err := strconv.ParseFloat(durationText, 64); err == nil && duration > 0 && !math.IsNaN(duration) && !math.IsInf(duration, 0) {
+			rounded := math.Round(duration)
+			if rounded <= 0 {
+				rounded = 1
+			}
+			metadata.Duration = rounded
+		}
+	}
+	if probed.Streams != nil {
+		metadata.HasAudioKnown = true
+		for _, stream := range probed.Streams {
+			if strings.TrimSpace(stream.CodecType) == "audio" {
+				metadata.HasAudio = true
+				break
+			}
+		}
+	}
+	if metadata.Duration <= 0 && !metadata.HasAudioKnown {
+		return metadata, fmt.Errorf("invalid video metadata: %q", trimForLog(string(output)))
+	}
+	return metadata, nil
+}
+
+func trimForLog(value string) string {
+	value = strings.TrimSpace(value)
+	if len(value) <= 120 {
+		return value
+	}
+	return value[:120] + "..."
+}