diff --git a/pom.xml b/pom.xml
index 4f16782..1e256ed 100644
--- a/pom.xml
+++ b/pom.xml
@@ -17,6 +17,7 @@
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<distroDirectory>${project.basedir}/distro</distroDirectory>
 		<serviceClass>InformationSystem</serviceClass>
+		<jackson.version>2.2.3</jackson.version>
 	</properties>
 
 	<scm>
@@ -26,6 +27,21 @@
 	</scm>
 
 	<dependencies>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+			<version>${jackson.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-annotations</artifactId>
+			<version>${jackson.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-core</artifactId>
+			<version>${jackson.version}</version>
+		</dependency>
 
 		<dependency>
 			<groupId>org.slf4j</groupId>
diff --git a/src/main/java/org/gcube/informationsystem/impl/entity/EntityImpl.java b/src/main/java/org/gcube/informationsystem/impl/entity/EntityImpl.java
new file mode 100644
index 0000000..fe85208
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/impl/entity/EntityImpl.java
@@ -0,0 +1,32 @@
+/**
+ * 
+ */
+package org.gcube.informationsystem.impl.entity;
+
+import org.gcube.informationsystem.model.entity.Entity;
+import org.gcube.informationsystem.model.entity.Header;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+/**
+ * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
+ *
+ */
+public abstract class EntityImpl implements Entity {
+
+	@JsonDeserialize(as = HeaderImpl.class)
+	protected Header header;
+	
+	@SuppressWarnings("unused")
+	private EntityImpl(){}
+	
+	protected EntityImpl(String name, String description, String version){
+		this.header = new HeaderImpl(name, description, version);
+	}
+	
+	@Override
+	public Header getHeader() {
+		return this.header;
+	}
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/impl/entity/FacetImpl.java b/src/main/java/org/gcube/informationsystem/impl/entity/FacetImpl.java
new file mode 100644
index 0000000..ca7f2fe
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/impl/entity/FacetImpl.java
@@ -0,0 +1,24 @@
+/**
+ * 
+ */
+package org.gcube.informationsystem.impl.entity;
+
+import org.gcube.informationsystem.model.entity.Facet;
+
+/**
+ * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
+ *
+ */
+public abstract class FacetImpl extends EntityImpl implements Facet {
+
+	/**
+	 * @param name
+	 * @param description
+	 * @param version
+	 */
+	protected FacetImpl(String name, String description, String version) {
+		super(name, description, version);
+	}
+
+	
+}
diff --git a/src/main/java/org/gcube/informationsystem/impl/entity/HeaderImpl.java b/src/main/java/org/gcube/informationsystem/impl/entity/HeaderImpl.java
new file mode 100644
index 0000000..8140a09
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/impl/entity/HeaderImpl.java
@@ -0,0 +1,79 @@
+/**
+ * 
+ */
+package org.gcube.informationsystem.impl.entity;
+
+import java.util.Calendar;
+
+import org.gcube.informationsystem.model.entity.Header;
+
+/**
+ * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
+ *
+ */
+public class HeaderImpl implements Header {
+
+	protected String id;
+	protected String creator;
+	protected Calendar creationTime;
+	protected Calendar lastUpdateTime;
+	protected String name;
+	protected String description;
+	protected String version;
+	
+	@SuppressWarnings("unused")
+	private HeaderImpl(){
+		
+	}
+	
+	protected HeaderImpl(String name, String description, String version){
+		this.name = name;
+		this.description = description;
+		this.version = version;
+	}
+
+	@Override
+	public String getID() {
+		return this.id;
+	}
+	
+	protected void setID(String id){
+		this.id = id;
+	}
+
+	@Override
+	public String getCreator() {
+		return this.creator;
+	}
+	
+	protected void setCreator(String creator){
+		this.creator = creator;
+	}
+	
+	@Override
+	public Calendar getCreationTime() {
+		return creationTime;
+	}
+
+	@Override
+	public Calendar getLastUpdateTime() {
+		return lastUpdateTime;
+	}
+
+	@Override
+	public String getName() {
+		return this.name;
+	}
+
+	@Override
+	public String getDescription() {
+		return this.description;
+	}
+
+
+	@Override
+	public String getVersion() {
+		return this.version;
+	}
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/impl/entity/ResourceImpl.java b/src/main/java/org/gcube/informationsystem/impl/entity/ResourceImpl.java
new file mode 100644
index 0000000..d4b6f9e
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/impl/entity/ResourceImpl.java
@@ -0,0 +1,87 @@
+/**
+ * 
+ */
+package org.gcube.informationsystem.impl.entity;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.gcube.informationsystem.model.entity.Facet;
+import org.gcube.informationsystem.model.entity.Resource;
+import org.gcube.informationsystem.model.relation.RelationProperty;
+
+/**
+ * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
+ *
+ */
+public abstract class ResourceImpl extends EntityImpl implements Resource {
+
+	protected Map<Facet, RelationProperty> addedFacets;
+	protected Map<Facet, RelationProperty> attachedFacets;
+	protected List<Facet> detachedFacets;
+	
+	
+	protected Map<Resource, RelationProperty> attachedResourceProfiles;
+	protected List<Resource> detachedResourceProfiles;
+	
+	/**
+	 * @param name
+	 * @param description
+	 * @param version
+	 */
+	protected ResourceImpl(String name, String description, String version) {
+		super(name, description, version);
+		addedFacets = new HashMap<Facet, RelationProperty>();
+		attachedFacets = new HashMap<Facet, RelationProperty>();
+		detachedFacets = new ArrayList<>();
+		
+		
+		
+	}
+	
+	@Override
+	public void addFacet(Facet facet) {
+		addedFacets.put(facet, null);
+		
+	}
+
+	@Override
+	public void addFacet(Facet facet, RelationProperty relationProperty) {
+		addedFacets.put(facet, relationProperty);
+	}
+
+	@Override
+	public void attachFacet(Facet facet) {
+		attachedFacets.put(facet, null);
+	}
+
+	@Override
+	public void attachFacet(Facet facet, RelationProperty relationProperty) {
+		attachedFacets.put(facet, relationProperty);
+	}
+
+	@Override
+	public void detachFacet(Facet facet) {
+		detachedFacets.add(facet);
+		attachedFacets.remove(facet);
+	}
+
+	@Override
+	public void attachResource(Resource resource) {
+		
+	}
+
+	@Override
+	public void attachResource(Resource resource,
+			RelationProperty relationProperty) {
+
+	}
+
+	@Override
+	public void detachResource(Resource resource) {
+		
+	}
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/impl/relation/ConsistOfImpl.java b/src/main/java/org/gcube/informationsystem/impl/relation/ConsistOfImpl.java
new file mode 100644
index 0000000..a4d3030
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/impl/relation/ConsistOfImpl.java
@@ -0,0 +1,28 @@
+/**
+ * 
+ */
+package org.gcube.informationsystem.impl.relation;
+
+import org.gcube.informationsystem.model.entity.Facet;
+import org.gcube.informationsystem.model.entity.Resource;
+import org.gcube.informationsystem.model.relation.ConsistOf;
+import org.gcube.informationsystem.model.relation.RelationProperty;
+
+/**
+ * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
+ * 
+ */
+public class ConsistOfImpl<Out extends Resource, In extends Facet> extends
+		RelationImpl<Out, In> implements ConsistOf<Out, In> {
+
+	/**
+	 * @param source
+	 * @param target
+	 * @param relationProperty
+	 */
+	public ConsistOfImpl(Out source, In target,
+			RelationProperty relationProperty) {
+		super(source, target, relationProperty);
+	}
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/impl/relation/RelatedToImpl.java b/src/main/java/org/gcube/informationsystem/impl/relation/RelatedToImpl.java
new file mode 100644
index 0000000..9386e97
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/impl/relation/RelatedToImpl.java
@@ -0,0 +1,27 @@
+/**
+ * 
+ */
+package org.gcube.informationsystem.impl.relation;
+
+import org.gcube.informationsystem.model.entity.Resource;
+import org.gcube.informationsystem.model.relation.RelatedTo;
+import org.gcube.informationsystem.model.relation.RelationProperty;
+
+/**
+ * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
+ * 
+ */
+public class RelatedToImpl<Out extends Resource, In extends Resource> extends
+		RelationImpl<Out, In> implements RelatedTo<Out, In> {
+
+	/**
+	 * @param source
+	 * @param target
+	 * @param relationProperty
+	 */
+	public RelatedToImpl(Out source, In target,
+			RelationProperty relationProperty) {
+		super(source, target, relationProperty);
+	}
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/impl/relation/RelationImpl.java b/src/main/java/org/gcube/informationsystem/impl/relation/RelationImpl.java
new file mode 100644
index 0000000..fbe60bf
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/impl/relation/RelationImpl.java
@@ -0,0 +1,44 @@
+/**
+ * 
+ */
+package org.gcube.informationsystem.impl.relation;
+
+import org.gcube.informationsystem.model.entity.Entity;
+import org.gcube.informationsystem.model.relation.Relation;
+import org.gcube.informationsystem.model.relation.RelationProperty;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+/**
+ * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
+ *
+ */
+public abstract class RelationImpl<Out extends Entity, In extends Entity> implements Relation<Out, In> {
+
+	protected Out source;
+	protected In target;
+	@JsonDeserialize(as = RelationPropertyImpl.class)
+	protected RelationProperty relationProperty;
+	
+	protected RelationImpl(Out source, In target, RelationProperty relationProperty){
+		this.source = source;
+		this.target = target;
+		this.relationProperty = relationProperty;
+	}
+	
+	@Override
+	public Out getSource() {
+		return null;
+	}
+
+	@Override
+	public In getTarget() {
+		return null;
+	}
+
+	@Override
+	public RelationProperty getRelationProperty() {
+		return this.relationProperty;
+	}
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/impl/relation/RelationPropertyImpl.java b/src/main/java/org/gcube/informationsystem/impl/relation/RelationPropertyImpl.java
new file mode 100644
index 0000000..f51a102
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/impl/relation/RelationPropertyImpl.java
@@ -0,0 +1,53 @@
+/**
+ * 
+ */
+package org.gcube.informationsystem.impl.relation;
+
+import org.gcube.informationsystem.impl.AccessPolicyImpl;
+import org.gcube.informationsystem.model.AccessPolicy;
+import org.gcube.informationsystem.model.relation.RelationProperty;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+/**
+ * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
+ *
+ */
+public class RelationPropertyImpl implements RelationProperty {
+
+	protected String purpose;
+	protected ReferentiaIntegrity referentiaIntegrity;
+	@JsonDeserialize(as = AccessPolicyImpl.class)
+	protected AccessPolicy accessPolicy;
+	
+	@Override
+	public String getPurpose() {
+		return this.purpose;
+	}
+
+	@Override
+	public void setPurpose(String purpose) {
+		this.purpose = purpose;
+	}
+
+	@Override
+	public ReferentiaIntegrity getReferentialIntegrity() {
+		return this.referentiaIntegrity;
+	}
+
+	@Override
+	public void setReferentialIntegrity(ReferentiaIntegrity referentialIntegrity) {
+		this.referentiaIntegrity = referentialIntegrity;
+	}
+
+	@Override
+	public AccessPolicy getPolicy() {
+		return this.accessPolicy;
+	}
+
+	@Override
+	public void setPolicy(AccessPolicy accessPolicy) {
+		this.accessPolicy = accessPolicy;
+	}
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/model/entity/Entity.java b/src/main/java/org/gcube/informationsystem/model/entity/Entity.java
index 5fe7405..0dc9f0f 100644
--- a/src/main/java/org/gcube/informationsystem/model/entity/Entity.java
+++ b/src/main/java/org/gcube/informationsystem/model/entity/Entity.java
@@ -3,7 +3,6 @@
  */
 package org.gcube.informationsystem.model.entity;
 
-import org.gcube.informationsystem.model.Header;
 
 
 
diff --git a/src/main/java/org/gcube/informationsystem/model/Header.java b/src/main/java/org/gcube/informationsystem/model/entity/Header.java
similarity index 89%
rename from src/main/java/org/gcube/informationsystem/model/Header.java
rename to src/main/java/org/gcube/informationsystem/model/entity/Header.java
index 8f95aad..2bb6bd1 100644
--- a/src/main/java/org/gcube/informationsystem/model/Header.java
+++ b/src/main/java/org/gcube/informationsystem/model/entity/Header.java
@@ -1,7 +1,7 @@
 /**
  * 
  */
-package org.gcube.informationsystem.model;
+package org.gcube.informationsystem.model.entity;
 
 import java.util.Calendar;