diff --git a/protocol/types.go b/protocol/types.go
index d161428..13e9a29 100644
--- a/protocol/types.go
+++ b/protocol/types.go
@@ -4121,16 +4121,28 @@ func FindQueuedTask(tasks []Task, orgID, poolID string) (Task, bool) {
 }
 
 type TaskArtifact struct {
-	TaskID      string    `json:"task_id"`
-	ProofID     string    `json:"proof_id"`
-	PoolID      string    `json:"pool_id"`
-	Name        string    `json:"name"`
-	Ref         string    `json:"ref"`
-	ContentType string    `json:"content_type,omitempty"`
-	SHA256      string    `json:"sha256"`
-	SizeBytes   int64     `json:"size_bytes"`
-	CreatedAt   time.Time `json:"created_at"`
-	ExpiresAt   time.Time `json:"expires_at"`
+	TaskID                 string           `json:"task_id"`
+	ProofID                string           `json:"proof_id"`
+	PoolID                 string           `json:"pool_id"`
+	Name                   string           `json:"name"`
+	Ref                    string           `json:"ref"`
+	ContentType            string           `json:"content_type,omitempty"`
+	SHA256                 string           `json:"sha256"`
+	SizeBytes              int64            `json:"size_bytes"`
+	CreatedAt              time.Time        `json:"created_at"`
+	ExpiresAt              time.Time        `json:"expires_at"`
+	ArtifactClass          string           `json:"artifact_class,omitempty"`
+	Visibility             AccessVisibility `json:"visibility,omitempty"`
+	UploaderKind           string           `json:"uploader_kind,omitempty"`
+	UploaderID             string           `json:"uploader_id,omitempty"`
+	PolicySource           string           `json:"policy_source,omitempty"`
+	PolicyRef              string           `json:"policy_ref,omitempty"`
+	PolicyHash             string           `json:"policy_hash,omitempty"`
+	ProviderEnrollmentID   string           `json:"provider_enrollment_id,omitempty"`
+	PolicyRetentionSeconds int              `json:"policy_retention_seconds,omitempty"`
+	PolicyRequestAdjusted  bool             `json:"policy_request_adjusted,omitempty"`
+	Truncated              bool             `json:"truncated,omitempty"`
+	OriginalSizeBytes      int64            `json:"original_size_bytes,omitempty"`
 }
 
 type Lease struct {
diff --git a/protocol/types_test.go b/protocol/types_test.go
index a081ddd..fd0e164 100644
--- a/protocol/types_test.go
+++ b/protocol/types_test.go
@@ -77,6 +77,30 @@ func TestTaskArtifactExactJSONRoundTrip(t *testing.T) {
 	}
 }
 
+func TestTaskArtifactDecodesRunLogPolicyMetadata(t *testing.T) {
+	const fixture = `{"task_id":"task-1","proof_id":"proof-1","pool_id":"pool-1","name":"run-logs/stderr.txt","ref":"artifact://pool-1/tasks/task-1/proofs/proof-1/run-logs/stderr.txt","content_type":"text/plain","sha256":"sha256:fixture","size_bytes":34,"created_at":"2026-07-11T12:00:00Z","expires_at":"2026-07-11T13:00:00Z","artifact_class":"run-log","visibility":"private","uploader_kind":"agent","uploader_id":"worker-1","policy_source":"task-label","policy_ref":"workflow.compute.run_logs.preserve","policy_hash":"sha256:policy","provider_enrollment_id":"enrollment-1","policy_retention_seconds":600,"policy_request_adjusted":true,"truncated":true,"original_size_bytes":4096}`
+	var artifact protocol.TaskArtifact
+	if err := protocol.DecodeStrict(strings.NewReader(fixture), &artifact); err != nil {
+		t.Fatalf("strict decode task artifact policy metadata: %v", err)
+	}
+	got, err := json.Marshal(artifact)
+	if err != nil {
+		t.Fatalf("marshal task artifact policy metadata: %v", err)
+	}
+	if string(got) != fixture {
+		t.Fatalf("task artifact policy metadata JSON = %s, want %s", got, fixture)
+	}
+}
+
+func TestTaskArtifactRejectsUnknownRunLogPolicyMetadata(t *testing.T) {
+	const fixture = `{"task_id":"task-1","proof_id":"proof-1","pool_id":"pool-1","name":"run-logs/stderr.txt","ref":"artifact://pool-1/tasks/task-1/proofs/proof-1/run-logs/stderr.txt","sha256":"sha256:fixture","size_bytes":34,"created_at":"2026-07-11T12:00:00Z","expires_at":"2026-07-11T13:00:00Z","artifact_class":"run-log","unexpected_policy_field":true}`
+	var artifact protocol.TaskArtifact
+	err := protocol.DecodeStrict(strings.NewReader(fixture), &artifact)
+	if err == nil || !strings.Contains(err.Error(), `unknown field "unexpected_policy_field"`) {
+		t.Fatalf("strict decode error = %v, want unknown nested task artifact field", err)
+	}
+}
+
 func TestRuntimeDescriptorProducesExecutorRef(t *testing.T) {
 	descriptor := protocol.RuntimeDescriptor{
 		Name:                  "sandboxed-command",