diff --git a/dms/README.md b/dms/README.md
index 4e7d6238..42896720 100644
--- a/dms/README.md
+++ b/dms/README.md
@@ -29,6 +29,10 @@ Fachliche Routen (z. B. `POST /retention/destroy-callback`) liegen unter dem Pr
 `scripts/check-route-prefixes.sh`); nur `/healthz` und `/metrics` bleiben auf Wurzelebene. Die bei archive
 registrierte Rückruf-URL (`NEXARCH_DMS_APP_RETENTION_CALLBACK_URL`) muss den Präfix enthalten.
 
+## Objekt-Speicher
+
+`NEXARCH_DMS_APP_STORAGE_DRIVER` und `NEXARCH_DMS_WORKER_STORAGE_DRIVER` wählen den Treiber: `local` (Standard, braucht `…_STORAGE_DIR`) oder `s3`. Für `s3` sind `…_S3_BUCKET`, `…_S3_ACCESS_KEY_ID` und `…_S3_SECRET_ACCESS_KEY` Pflicht; optional `…_S3_REGION` (Standard `us-east-1`), `…_S3_ENDPOINT_URL` (MinIO, Ceph) und `…_S3_PATH_STYLE=1`. App und Worker müssen denselben Bucket nutzen.
+
 ## Struktur
 
 - `cmd/app` — Anfrage-Dienst (HTTP), blockiert nie durch lange Aufgaben
diff --git a/dms/cmd/app/api.go b/dms/cmd/app/api.go
index 11b2a25c..23868e76 100644
--- a/dms/cmd/app/api.go
+++ b/dms/cmd/app/api.go
@@ -41,10 +41,10 @@ type uploadStack struct {
 }
 
 func newUploadStack(pool *pgxpool.Pool, stagingDir string) uploadStack {
-	storageDir := os.Getenv("NEXARCH_DMS_APP_STORAGE_DIR")
-	signingSecret := os.Getenv("NEXARCH_DMS_APP_STORAGE_SIGNING_SECRET")
-	publicBaseURL := os.Getenv("NEXARCH_DMS_APP_STORAGE_PUBLIC_BASE_URL")
-	driver := storage.NewLocalDriver(storageDir, []byte(signingSecret), publicBaseURL, signedURLMaxTTL(os.Getenv("NEXARCH_DMS_APP_SIGNED_URL_MAX_TTL")))
+	driver, err := storage.NewDriverFromEnv(context.Background(), "NEXARCH_DMS_APP")
+	if err != nil {
+		log.Fatalf("dms-app: %v", err)
+	}
 	usageReporter := storage.NewHTTPUsageReporter(
 		os.Getenv("NEXARCH_DMS_APP_USAGE_ENDPOINT_URL"),
 		os.Getenv("NEXARCH_DMS_APP_USAGE_CLIENT_ID"),
diff --git a/dms/cmd/app/main.go b/dms/cmd/app/main.go
index c544c12c..fbc36a03 100644
--- a/dms/cmd/app/main.go
+++ b/dms/cmd/app/main.go
@@ -194,10 +194,10 @@ func setupRetention(mux *http.ServeMux, dsn string) {
 		log.Fatalf("dms-app: datenbankverbindung: %v", err)
 	}
 
-	storageDir := os.Getenv("NEXARCH_DMS_APP_STORAGE_DIR")
-	signingSecret := os.Getenv("NEXARCH_DMS_APP_STORAGE_SIGNING_SECRET")
-	publicBaseURL := os.Getenv("NEXARCH_DMS_APP_STORAGE_PUBLIC_BASE_URL")
-	driver := storage.NewLocalDriver(storageDir, []byte(signingSecret), publicBaseURL, signedURLMaxTTL(os.Getenv("NEXARCH_DMS_APP_SIGNED_URL_MAX_TTL")))
+	driver, err := storage.NewDriverFromEnv(ctx, "NEXARCH_DMS_APP")
+	if err != nil {
+		log.Fatalf("dms-app: %v", err)
+	}
 
 	usageEndpoint := os.Getenv("NEXARCH_DMS_APP_USAGE_ENDPOINT_URL")
 	usageClientID := os.Getenv("NEXARCH_DMS_APP_USAGE_CLIENT_ID")
@@ -360,11 +360,3 @@ func setupWatchFolder(ctx context.Context, dir string) {
 		}
 	}()
 }
-
-func signedURLMaxTTL(raw string) time.Duration {
-	ttl, err := storage.ParseMaxSignedURLTTL(raw)
-	if err != nil {
-		log.Fatalf("dms-app: %v", err)
-	}
-	return ttl
-}
diff --git a/dms/cmd/worker/main.go b/dms/cmd/worker/main.go
index 7743e0bb..f5c92ff0 100644
--- a/dms/cmd/worker/main.go
+++ b/dms/cmd/worker/main.go
@@ -133,14 +133,16 @@ func processRetentionRegisterJobs(ctx context.Context, queue *jobqueue.Queue, cl
 // startJobWorkers verdrahtet alle Fachjobs (FDN-17). Fehlt die Storage-/Schluessel-
 // Konfiguration, werden sie nicht gestartet und das wird gemeldet.
 func startJobWorkers(ctx context.Context, pool *pgxpool.Pool, queue *jobqueue.Queue, tracker *errortracking.Tracker) {
-	storageDir := os.Getenv("NEXARCH_DMS_WORKER_STORAGE_DIR")
 	tenantSlug := os.Getenv("NEXARCH_DMS_WORKER_TENANT_SLUG")
 	kekURL := os.Getenv("NEXARCH_DMS_WORKER_KEK_ENDPOINT_URL")
-	if storageDir == "" || tenantSlug == "" || kekURL == "" {
-		log.Print("dms-worker: NEXARCH_DMS_WORKER_STORAGE_DIR/_TENANT_SLUG/_KEK_ENDPOINT_URL unvollstaendig, Fachjobs (Vorschau, Konvertierung, Virenscan, Export, Texterkennung) werden NICHT verarbeitet")
+	if !storage.ConfiguredFromEnv("NEXARCH_DMS_WORKER") || tenantSlug == "" || kekURL == "" {
+		log.Print("dms-worker: NEXARCH_DMS_WORKER_STORAGE_DIR (oder _STORAGE_DRIVER=s3 mit _S3_BUCKET)/_TENANT_SLUG/_KEK_ENDPOINT_URL unvollstaendig, Fachjobs (Vorschau, Konvertierung, Virenscan, Export, Texterkennung) werden NICHT verarbeitet")
 		return
 	}
-	driver := storage.NewLocalDriver(storageDir, []byte(os.Getenv("NEXARCH_DMS_WORKER_STORAGE_SIGNING_SECRET")), os.Getenv("NEXARCH_DMS_WORKER_STORAGE_PUBLIC_BASE_URL"), signedURLMaxTTL(os.Getenv("NEXARCH_DMS_WORKER_SIGNED_URL_MAX_TTL")))
+	driver, err := storage.NewDriverFromEnv(ctx, "NEXARCH_DMS_WORKER")
+	if err != nil {
+		log.Fatalf("dms-worker: %v", err)
+	}
 	usage := storage.NewHTTPUsageReporter(os.Getenv("NEXARCH_DMS_WORKER_USAGE_ENDPOINT_URL"), os.Getenv("NEXARCH_DMS_WORKER_USAGE_CLIENT_ID"), os.Getenv("NEXARCH_DMS_WORKER_USAGE_CLIENT_SECRET"), nil)
 	cryptoSvc := dmscrypto.NewService(dmscrypto.NewHTTPKEKProvider(kekURL, os.Getenv("NEXARCH_DMS_WORKER_KEK_CLIENT_ID"), os.Getenv("NEXARCH_DMS_WORKER_KEK_CLIENT_SECRET"), nil))
 
@@ -304,11 +306,3 @@ func startJobWorkers(ctx context.Context, pool *pgxpool.Pool, queue *jobqueue.Qu
 		go integrity.RunScheduler(ctx, pool, queue, integritySched, 30*time.Second)
 	}
 }
-
-func signedURLMaxTTL(raw string) time.Duration {
-	ttl, err := storage.ParseMaxSignedURLTTL(raw)
-	if err != nil {
-		log.Fatalf("dms-worker: %v", err)
-	}
-	return ttl
-}
diff --git a/dms/internal/storage/fromenv.go b/dms/internal/storage/fromenv.go
new file mode 100644
index 00000000..e88f1e01
--- /dev/null
+++ b/dms/internal/storage/fromenv.go
@@ -0,0 +1,42 @@
+package storage
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strings"
+)
+
+// NewDriverFromEnv wählt den Treiber über <prefix>_STORAGE_DRIVER ("local",
+// Standard, oder "s3"). Zugangsdaten kommen nur aus der Umgebung.
+func NewDriverFromEnv(ctx context.Context, prefix string) (Driver, error) {
+	env := func(name string) string { return os.Getenv(prefix + "_" + name) }
+	ttl, err := ParseMaxSignedURLTTL(env("SIGNED_URL_MAX_TTL"))
+	if err != nil {
+		return nil, err
+	}
+	switch strings.ToLower(env("STORAGE_DRIVER")) {
+	case "", "local":
+		return NewLocalDriver(env("STORAGE_DIR"), []byte(env("STORAGE_SIGNING_SECRET")), env("STORAGE_PUBLIC_BASE_URL"), ttl), nil
+	case "s3":
+		bucket, key, secret := env("S3_BUCKET"), env("S3_ACCESS_KEY_ID"), env("S3_SECRET_ACCESS_KEY")
+		if bucket == "" || key == "" || secret == "" {
+			return nil, fmt.Errorf("storage: %s_S3_BUCKET, _S3_ACCESS_KEY_ID und _S3_SECRET_ACCESS_KEY sind erforderlich", prefix)
+		}
+		region := env("S3_REGION")
+		if region == "" {
+			region = "us-east-1"
+		}
+		return NewS3Driver(ctx, bucket, region, env("S3_ENDPOINT_URL"), key, secret, env("S3_PATH_STYLE") == "1", ttl)
+	default:
+		return nil, fmt.Errorf("storage: %s_STORAGE_DRIVER %q unbekannt (local oder s3)", prefix, env("STORAGE_DRIVER"))
+	}
+}
+
+// ConfiguredFromEnv meldet, ob für prefix ein Speicher konfiguriert ist.
+func ConfiguredFromEnv(prefix string) bool {
+	if strings.EqualFold(os.Getenv(prefix+"_STORAGE_DRIVER"), "s3") {
+		return os.Getenv(prefix+"_S3_BUCKET") != ""
+	}
+	return os.Getenv(prefix+"_STORAGE_DIR") != ""
+}
diff --git a/dms/internal/storage/fromenv_test.go b/dms/internal/storage/fromenv_test.go
new file mode 100644
index 00000000..1e68d78b
--- /dev/null
+++ b/dms/internal/storage/fromenv_test.go
@@ -0,0 +1,69 @@
+package storage
+
+import (
+	"context"
+	"testing"
+)
+
+func TestNewDriverFromEnv(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("Standard ist lokal", func(t *testing.T) {
+		t.Setenv("X_STORAGE_DIR", t.TempDir())
+		d, err := NewDriverFromEnv(ctx, "X")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, ok := d.(*LocalDriver); !ok {
+			t.Fatalf("erwartet *LocalDriver, bekam %T", d)
+		}
+	})
+
+	t.Run("s3 mit Zugangsdaten", func(t *testing.T) {
+		t.Setenv("X_STORAGE_DRIVER", "S3")
+		t.Setenv("X_S3_BUCKET", "b")
+		t.Setenv("X_S3_ACCESS_KEY_ID", "k")
+		t.Setenv("X_S3_SECRET_ACCESS_KEY", "s")
+		t.Setenv("X_S3_ENDPOINT_URL", "http://127.0.0.1:9000")
+		d, err := NewDriverFromEnv(ctx, "X")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, ok := d.(*S3Driver); !ok {
+			t.Fatalf("erwartet *S3Driver, bekam %T", d)
+		}
+	})
+
+	t.Run("s3 ohne Zugangsdaten schlaegt fehl", func(t *testing.T) {
+		t.Setenv("X_STORAGE_DRIVER", "s3")
+		t.Setenv("X_S3_BUCKET", "b")
+		if _, err := NewDriverFromEnv(ctx, "X"); err == nil {
+			t.Fatal("erwartet Fehler ohne Schluessel")
+		}
+	})
+
+	t.Run("unbekannter Treiber", func(t *testing.T) {
+		t.Setenv("X_STORAGE_DRIVER", "ftp")
+		if _, err := NewDriverFromEnv(ctx, "X"); err == nil {
+			t.Fatal("erwartet Fehler fuer unbekannten Treiber")
+		}
+	})
+}
+
+func TestConfiguredFromEnv(t *testing.T) {
+	if ConfiguredFromEnv("Y") {
+		t.Fatal("ohne Variablen nicht konfiguriert")
+	}
+	t.Setenv("Y_STORAGE_DIR", "/x")
+	if !ConfiguredFromEnv("Y") {
+		t.Fatal("STORAGE_DIR zaehlt als konfiguriert")
+	}
+	t.Setenv("Y_STORAGE_DRIVER", "s3")
+	if ConfiguredFromEnv("Y") {
+		t.Fatal("s3 braucht den Bucket")
+	}
+	t.Setenv("Y_S3_BUCKET", "b")
+	if !ConfiguredFromEnv("Y") {
+		t.Fatal("s3 mit Bucket ist konfiguriert")
+	}
+}