diff --git a/dragon.gif b/dragon.gif
deleted file mode 100644
index c59d4f7..0000000
Binary files a/dragon.gif and /dev/null differ
diff --git a/fr/istic/nplouzeau/cartaylor/api/Category.java b/fr/istic/nplouzeau/cartaylor/api/Category.java
new file mode 100644
index 0000000..cd3e284
--- /dev/null
+++ b/fr/istic/nplouzeau/cartaylor/api/Category.java
@@ -0,0 +1,9 @@
+package fr.istic.nplouzeau.cartaylor.api;
+/**
+ * @author plouzeau
+ * <p>
+ * A public type to organize part types in categories
+ */
+public interface Category {
+    String getName();
+}
\ No newline at end of file
diff --git a/fr/istic/nplouzeau/cartaylor/api/CompatibilityChecker.java b/fr/istic/nplouzeau/cartaylor/api/CompatibilityChecker.java
new file mode 100644
index 0000000..0542ee7
--- /dev/null
+++ b/fr/istic/nplouzeau/cartaylor/api/CompatibilityChecker.java
@@ -0,0 +1,6 @@
+package fr.istic.nplouzeau.cartaylor.api;
+import java.util.Set;
+public interface CompatibilityChecker {
+    Set<PartType> getIncompatibilities(PartType reference);
+    Set<PartType> getRequirements(PartType reference);
+}
\ No newline at end of file
diff --git a/fr/istic/nplouzeau/cartaylor/api/CompatibilityManager.java b/fr/istic/nplouzeau/cartaylor/api/CompatibilityManager.java
new file mode 100644
index 0000000..c5a753a
--- /dev/null
+++ b/fr/istic/nplouzeau/cartaylor/api/CompatibilityManager.java
@@ -0,0 +1,12 @@
+package fr.istic.nplouzeau.cartaylor.api;
+import java.util.Set;
+public interface CompatibilityManager extends CompatibilityChecker {
+    void addIncompatibilities(PartType reference,
+    Set<PartType> target);
+    void removeIncompatibility(PartType reference, PartType
+    target);
+    void addRequirements(PartType reference, Set<PartType>
+    target);
+    void removeRequirement(PartType reference, PartType
+    target);
+}
\ No newline at end of file
diff --git a/fr/istic/nplouzeau/cartaylor/api/Configuration.java b/fr/istic/nplouzeau/cartaylor/api/Configuration.java
new file mode 100644
index 0000000..00623af
--- /dev/null
+++ b/fr/istic/nplouzeau/cartaylor/api/Configuration.java
@@ -0,0 +1,11 @@
+package fr.istic.nplouzeau.cartaylor.api;
+import java.util.Set;
+public interface Configuration {
+    boolean isValid();
+    boolean isComplete();
+    Set<PartType> getSelectedParts();
+    void selectPart(PartType chosenPart);
+    PartType getSelectionForCategory(Category category);
+    void unselectPartType(Category categoryToClear);
+    void clear();
+}
\ No newline at end of file
diff --git a/fr/istic/nplouzeau/cartaylor/api/Configurator.java b/fr/istic/nplouzeau/cartaylor/api/Configurator.java
new file mode 100644
index 0000000..191eed7
--- /dev/null
+++ b/fr/istic/nplouzeau/cartaylor/api/Configurator.java
@@ -0,0 +1,8 @@
+package fr.istic.nplouzeau.cartaylor.api;
+import java.util.Set;
+public interface Configurator {
+    Set<Category> getCategories();
+    Set<PartType> getVariants(Category category);
+    Configuration getConfiguration();
+    CompatibilityChecker getCompatibilityChecker();
+}
\ No newline at end of file
diff --git a/fr/istic/nplouzeau/cartaylor/api/PartType.java b/fr/istic/nplouzeau/cartaylor/api/PartType.java
new file mode 100644
index 0000000..35101af
--- /dev/null
+++ b/fr/istic/nplouzeau/cartaylor/api/PartType.java
@@ -0,0 +1,5 @@
+package fr.istic.nplouzeau.cartaylor.api;
+public interface PartType {
+    String getName();
+    Category getCategory();
+}
\ No newline at end of file