diff --git a/src/main/java/eu/eudat/file/transformer/interfaces/FileTransformerClient.java b/src/main/java/eu/eudat/file/transformer/interfaces/FileTransformerClient.java
index 8fc199f..0806359 100644
--- a/src/main/java/eu/eudat/file/transformer/interfaces/FileTransformerClient.java
+++ b/src/main/java/eu/eudat/file/transformer/interfaces/FileTransformerClient.java
@@ -22,10 +22,10 @@ public interface FileTransformerClient {
      * @return a string representing the persistent digital object identifier (DOI)
      * @throws Exception if an error occurs while trying to deposit the dmp
      */
-    FileEnvelope exportDmp(DmpFileTransformerModel dmp) throws InvalidApplicationException, IOException;
+    FileEnvelope exportDmp(DmpFileTransformerModel dmp, String format) throws InvalidApplicationException, IOException;
     DmpFileTransformerModel importDmp(FileEnvelope file);
 
-    FileEnvelope exportDescription(DescriptionFileTransformerModel descriptionFileTransformerModel) throws InvalidApplicationException, IOException;
+    FileEnvelope exportDescription(DescriptionFileTransformerModel descriptionFileTransformerModel, String format) throws InvalidApplicationException, IOException;
     DescriptionFileTransformerModel importDescription(FileEnvelope file);
 
     FileTransformerConfiguration getConfiguration();
diff --git a/src/main/java/eu/eudat/file/transformer/interfaces/FileTransformerConfiguration.java b/src/main/java/eu/eudat/file/transformer/interfaces/FileTransformerConfiguration.java
index 42db218..8e9c7b7 100644
--- a/src/main/java/eu/eudat/file/transformer/interfaces/FileTransformerConfiguration.java
+++ b/src/main/java/eu/eudat/file/transformer/interfaces/FileTransformerConfiguration.java
@@ -1,12 +1,15 @@
 package eu.eudat.file.transformer.interfaces;
 
 
+import eu.eudat.file.transformer.models.misc.FileFormat;
+
+import java.util.List;
+
 public class FileTransformerConfiguration {
 
     private String fileTransformerId;
-    private String[] exportVariants;
-    private String[] importVariants;
-    private boolean hasLogo;
+    private List<FileFormat> exportVariants;
+    private List<FileFormat> importVariants;
 
     public String getFileTransformerId() {
         return fileTransformerId;
@@ -16,27 +19,19 @@ public class FileTransformerConfiguration {
         this.fileTransformerId = fileTransformerId;
     }
 
-    public String[] getExportVariants() {
+    public List<FileFormat> getExportVariants() {
         return exportVariants;
     }
 
-    public void setExportVariants(String[] exportVariants) {
+    public void setExportVariants(List<FileFormat> exportVariants) {
         this.exportVariants = exportVariants;
     }
 
-    public String[] getImportVariants() {
+    public List<FileFormat> getImportVariants() {
         return importVariants;
     }
 
-    public void setImportVariants(String[] importVariants) {
+    public void setImportVariants(List<FileFormat> importVariants) {
         this.importVariants = importVariants;
     }
-
-    public boolean isHasLogo() {
-        return hasLogo;
-    }
-
-    public void setHasLogo(boolean hasLogo) {
-        this.hasLogo = hasLogo;
-    }
 }
diff --git a/src/main/java/eu/eudat/file/transformer/models/misc/FileEnvelope.java b/src/main/java/eu/eudat/file/transformer/models/misc/FileEnvelope.java
index 3c2f855..a5cd979 100644
--- a/src/main/java/eu/eudat/file/transformer/models/misc/FileEnvelope.java
+++ b/src/main/java/eu/eudat/file/transformer/models/misc/FileEnvelope.java
@@ -2,7 +2,7 @@ package eu.eudat.file.transformer.models.misc;
 
 public class FileEnvelope {
     private String filename;
-    private byte[] file;
+    private String file;
 
     public String getFilename() {
         return filename;
@@ -12,11 +12,11 @@ public class FileEnvelope {
         this.filename = filename;
     }
 
-    public byte[] getFile() {
+    public String getFile() {
         return file;
     }
 
-    public void setFile(byte[] file) {
+    public void setFile(String file) {
         this.file = file;
     }
 }
diff --git a/src/main/java/eu/eudat/file/transformer/models/misc/FileFormat.java b/src/main/java/eu/eudat/file/transformer/models/misc/FileFormat.java
new file mode 100644
index 0000000..585f221
--- /dev/null
+++ b/src/main/java/eu/eudat/file/transformer/models/misc/FileFormat.java
@@ -0,0 +1,40 @@
+package eu.eudat.file.transformer.models.misc;
+
+public class FileFormat {
+    private String format;
+    private Boolean hasLogo;
+    private String icon;
+
+    public FileFormat(String format, Boolean hasLogo, String icon) {
+        this.format = format;
+        this.hasLogo = hasLogo;
+        this.icon = icon;
+    }
+
+    public FileFormat() {
+    }
+
+    public String getFormat() {
+        return format;
+    }
+
+    public void setFormat(String format) {
+        this.format = format;
+    }
+
+    public Boolean getHasLogo() {
+        return hasLogo;
+    }
+
+    public void setHasLogo(Boolean hasLogo) {
+        this.hasLogo = hasLogo;
+    }
+
+    public String getIcon() {
+        return icon;
+    }
+
+    public void setIcon(String icon) {
+        this.icon = icon;
+    }
+}