diff --git a/src/main/java/net/kemitix/gitdb/GitDB.java b/src/main/java/net/kemitix/gitdb/GitDB.java
index 32028ea..4bad3f5 100644
--- a/src/main/java/net/kemitix/gitdb/GitDB.java
+++ b/src/main/java/net/kemitix/gitdb/GitDB.java
@@ -21,6 +21,8 @@
 
 package net.kemitix.gitdb;
 
+import net.kemitix.gitdb.impl.LocalGitDB;
+
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Optional;
@@ -59,8 +61,6 @@ public interface GitDB {
      */
     static GitDB openLocal(final Path dbDir, final String userName, final String userEmailAddress) {
         return LocalGitDB.open(dbDir, userName, userEmailAddress);
-
-
     }
 
     /**
diff --git a/src/main/java/net/kemitix/gitdb/GitDBBranch.java b/src/main/java/net/kemitix/gitdb/GitDBBranch.java
index 823bd6e..b8eda62 100644
--- a/src/main/java/net/kemitix/gitdb/GitDBBranch.java
+++ b/src/main/java/net/kemitix/gitdb/GitDBBranch.java
@@ -21,54 +21,15 @@
 
 package net.kemitix.gitdb;
 
-import lombok.AccessLevel;
-import lombok.RequiredArgsConstructor;
-import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.Ref;
-import org.eclipse.jgit.lib.Repository;
-
-import java.io.*;
+import java.io.IOException;
 import java.util.Optional;
-import java.util.function.Function;
 
 /**
  * API for interacting with a branch in a GirDB.
  *
  * @author Paul Campbell (pcampbell@kemitix.net)
  */
-@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
-public class GitDBBranch {
-
-    private static final String KEY_PREFIX = "key:";
-    private final Ref branchRef;
-    private final GitDBRepo gitDBRepo;
-    private final String userName;
-    private final String userEmailAddress;
-
-    private static GitDBBranch select(
-            final Ref branchRef,
-            final GitDBRepo gitDBRepo,
-            final String userName,
-            final String userEmailAddress
-    ) {
-        return new GitDBBranch(branchRef, gitDBRepo, userName, userEmailAddress);
-    }
-
-    /**
-     * Initialise the creation of new GitDBBranch instances.
-     *
-     * @param repository       the Git Repository
-     * @param userName         the user name to record against changes
-     * @param userEmailAddress the user's email address to record against changes
-     * @return a Function for creating a GitDBBranch when supplied with a Ref for a branch
-     */
-    static Function<Ref, GitDBBranch> init(
-            final Repository repository,
-            final String userName,
-            final String userEmailAddress
-    ) {
-        return ref -> select(ref, new GitDBRepo(repository), userName, userEmailAddress);
-    }
+public interface GitDBBranch {
 
     /**
      * Lookup a value for the key.
@@ -77,9 +38,7 @@ public class GitDBBranch {
      * @return an Optional containing the value, if it exists, or empty if not
      * @throws IOException if there was an error reading the value
      */
-    public Optional<String> get(final String key) throws IOException {
-        return gitDBRepo.readValue(branchRef, KEY_PREFIX + key);
-    }
+    Optional<String> get(String key) throws IOException;
 
     /**
      * Put a value into the store for the key.
@@ -89,16 +48,7 @@ public class GitDBBranch {
      * @return an updated branch containing the new key/value
      * @throws IOException if there was an error writing the value
      */
-    public GitDBBranch put(final String key, final String value) throws IOException {
-        final ObjectId newTree = gitDBRepo.writeValue(branchRef, KEY_PREFIX + key, value);
-        final Ref newBranch =
-                gitDBRepo.writeCommit(branchRef, newTree, commitMessageForAdd(key, value), userName, userEmailAddress);
-        return select(newBranch, gitDBRepo, userName, userEmailAddress);
-    }
-
-    private String commitMessageForAdd(final String key, final String value) {
-        return String.format("Add key [%s] = [%s]", key, value);
-    }
+    GitDBBranch put(String key, String value) throws IOException;
 
     /**
      * Removes a key and its value from the store.
@@ -106,8 +56,5 @@ public class GitDBBranch {
      * @param key the key to remove
      * @return an updated branch without the key, or the original if the key was not found
      */
-    public GitDBBranch remove(final String key) {
-        return this;
-    }
-
+    GitDBBranch remove(String key);
 }
diff --git a/src/main/java/net/kemitix/gitdb/CommitWriter.java b/src/main/java/net/kemitix/gitdb/impl/CommitWriter.java
similarity index 99%
rename from src/main/java/net/kemitix/gitdb/CommitWriter.java
rename to src/main/java/net/kemitix/gitdb/impl/CommitWriter.java
index cbf28e8..290ab6b 100644
--- a/src/main/java/net/kemitix/gitdb/CommitWriter.java
+++ b/src/main/java/net/kemitix/gitdb/impl/CommitWriter.java
@@ -19,7 +19,7 @@
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-package net.kemitix.gitdb;
+package net.kemitix.gitdb.impl;
 
 import org.eclipse.jgit.lib.*;
 
diff --git a/src/main/java/net/kemitix/gitdb/impl/GitDBBranchImpl.java b/src/main/java/net/kemitix/gitdb/impl/GitDBBranchImpl.java
new file mode 100644
index 0000000..3b59ca8
--- /dev/null
+++ b/src/main/java/net/kemitix/gitdb/impl/GitDBBranchImpl.java
@@ -0,0 +1,96 @@
+/*
+  The MIT License (MIT)
+
+  Copyright (c) 2018 Paul Campbell
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+  and associated documentation files (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+  and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all copies
+  or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
+  AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package net.kemitix.gitdb.impl;
+
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+import net.kemitix.gitdb.GitDBBranch;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+
+import java.io.*;
+import java.util.Optional;
+import java.util.function.Function;
+
+/**
+ * API for interacting with a branch in a GirDB.
+ *
+ * @author Paul Campbell (pcampbell@kemitix.net)
+ */
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+class GitDBBranchImpl implements GitDBBranch {
+
+    private static final String KEY_PREFIX = "key:";
+    private final Ref branchRef;
+    private final GitDBRepo gitDBRepo;
+    private final String userName;
+    private final String userEmailAddress;
+
+    private static GitDBBranch select(
+            final Ref branchRef,
+            final GitDBRepo gitDBRepo,
+            final String userName,
+            final String userEmailAddress
+    ) {
+        return new GitDBBranchImpl(branchRef, gitDBRepo, userName, userEmailAddress);
+    }
+
+    /**
+     * Initialise the creation of new GitDBBranch instances.
+     *
+     * @param repository       the Git Repository
+     * @param userName         the user name to record against changes
+     * @param userEmailAddress the user's email address to record against changes
+     * @return a Function for creating a GitDBBranch when supplied with a Ref for a branch
+     */
+    static Function<Ref, GitDBBranch> init(
+            final Repository repository,
+            final String userName,
+            final String userEmailAddress
+    ) {
+        return ref -> select(ref, new GitDBRepo(repository), userName, userEmailAddress);
+    }
+
+    @Override
+    public Optional<String> get(final String key) throws IOException {
+        return gitDBRepo.readValue(branchRef, KEY_PREFIX + key);
+    }
+
+    @Override
+    public GitDBBranch put(final String key, final String value) throws IOException {
+        final ObjectId newTree = gitDBRepo.writeValue(branchRef, KEY_PREFIX + key, value);
+        final Ref newBranch =
+                gitDBRepo.writeCommit(branchRef, newTree, commitMessageForAdd(key, value), userName, userEmailAddress);
+        return select(newBranch, gitDBRepo, userName, userEmailAddress);
+    }
+
+    @Override
+    public GitDBBranch remove(final String key) {
+        return this;
+    }
+
+    private String commitMessageForAdd(final String key, final String value) {
+        return String.format("Add key [%s] = [%s]", key, value);
+    }
+
+}
diff --git a/src/main/java/net/kemitix/gitdb/GitDBRepo.java b/src/main/java/net/kemitix/gitdb/impl/GitDBRepo.java
similarity index 99%
rename from src/main/java/net/kemitix/gitdb/GitDBRepo.java
rename to src/main/java/net/kemitix/gitdb/impl/GitDBRepo.java
index d9d4c1f..33aaeab 100644
--- a/src/main/java/net/kemitix/gitdb/GitDBRepo.java
+++ b/src/main/java/net/kemitix/gitdb/impl/GitDBRepo.java
@@ -19,7 +19,7 @@
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-package net.kemitix.gitdb;
+package net.kemitix.gitdb.impl;
 
 import lombok.val;
 import org.eclipse.jgit.lib.*;
diff --git a/src/main/java/net/kemitix/gitdb/GitTreeReader.java b/src/main/java/net/kemitix/gitdb/impl/GitTreeReader.java
similarity index 99%
rename from src/main/java/net/kemitix/gitdb/GitTreeReader.java
rename to src/main/java/net/kemitix/gitdb/impl/GitTreeReader.java
index b299bb1..05e4911 100644
--- a/src/main/java/net/kemitix/gitdb/GitTreeReader.java
+++ b/src/main/java/net/kemitix/gitdb/impl/GitTreeReader.java
@@ -19,7 +19,7 @@
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-package net.kemitix.gitdb;
+package net.kemitix.gitdb.impl;
 
 import lombok.AccessLevel;
 import lombok.Getter;
diff --git a/src/main/java/net/kemitix/gitdb/InitGitDBRepo.java b/src/main/java/net/kemitix/gitdb/impl/InitGitDBRepo.java
similarity index 99%
rename from src/main/java/net/kemitix/gitdb/InitGitDBRepo.java
rename to src/main/java/net/kemitix/gitdb/impl/InitGitDBRepo.java
index a84f751..149a630 100644
--- a/src/main/java/net/kemitix/gitdb/InitGitDBRepo.java
+++ b/src/main/java/net/kemitix/gitdb/impl/InitGitDBRepo.java
@@ -19,7 +19,7 @@
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-package net.kemitix.gitdb;
+package net.kemitix.gitdb.impl;
 
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
diff --git a/src/main/java/net/kemitix/gitdb/KeyWriter.java b/src/main/java/net/kemitix/gitdb/impl/KeyWriter.java
similarity index 99%
rename from src/main/java/net/kemitix/gitdb/KeyWriter.java
rename to src/main/java/net/kemitix/gitdb/impl/KeyWriter.java
index e768188..1dc00c1 100644
--- a/src/main/java/net/kemitix/gitdb/KeyWriter.java
+++ b/src/main/java/net/kemitix/gitdb/impl/KeyWriter.java
@@ -19,7 +19,7 @@
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-package net.kemitix.gitdb;
+package net.kemitix.gitdb.impl;
 
 import org.eclipse.jgit.lib.*;
 
diff --git a/src/main/java/net/kemitix/gitdb/impl/LocalGitDB.java b/src/main/java/net/kemitix/gitdb/impl/LocalGitDB.java
new file mode 100644
index 0000000..b6bbb09
--- /dev/null
+++ b/src/main/java/net/kemitix/gitdb/impl/LocalGitDB.java
@@ -0,0 +1,61 @@
+/*
+  The MIT License (MIT)
+
+  Copyright (c) 2018 Paul Campbell
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+  and associated documentation files (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+  and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all copies
+  or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
+  AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package net.kemitix.gitdb.impl;
+
+import net.kemitix.gitdb.GitDB;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+/**
+ * API for connecting to a Local Git repo as a database.
+ *
+ * @author Paul Campbell (pcampbell@kemitix.net)
+ */
+public interface LocalGitDB extends GitDB {
+
+    /**
+     * Create a new GitDB instance, while initialising a new git repo.
+     *
+     * @param dbDir            the path to instantiate the git repo in
+     * @param userName         the user name
+     * @param userEmailAddress the user email address
+     * @return a GitDB instance for the created local gitdb
+     * @throws IOException if there {@code dbDir} is a file or a non-empty directory
+     */
+    static GitDB init(final Path dbDir, final String userName, final String userEmailAddress) throws IOException {
+        return LocalGitDBImpl.init(dbDir, userName, userEmailAddress);
+    }
+
+    /**
+     * Create a new GitDB instance using the Git repo.
+     *
+     * @param dbDir            the path to instantiate the git repo in
+     * @param userName         the user name
+     * @param userEmailAddress the user email address
+     * @return a GitDB instance for the created local gitdb
+     */
+    static GitDB open(final Path dbDir, final String userName, final String userEmailAddress) {
+        return LocalGitDBImpl.open(dbDir, userName, userEmailAddress);
+    }
+
+}
diff --git a/src/main/java/net/kemitix/gitdb/LocalGitDB.java b/src/main/java/net/kemitix/gitdb/impl/LocalGitDBImpl.java
similarity index 89%
rename from src/main/java/net/kemitix/gitdb/LocalGitDB.java
rename to src/main/java/net/kemitix/gitdb/impl/LocalGitDBImpl.java
index 001add7..7d9f4d7 100644
--- a/src/main/java/net/kemitix/gitdb/LocalGitDB.java
+++ b/src/main/java/net/kemitix/gitdb/impl/LocalGitDBImpl.java
@@ -19,8 +19,11 @@
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-package net.kemitix.gitdb;
+package net.kemitix.gitdb.impl;
 
+import net.kemitix.gitdb.GitDB;
+import net.kemitix.gitdb.GitDBBranch;
+import net.kemitix.gitdb.InvalidRepositoryException;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.lib.*;
 
@@ -34,7 +37,7 @@ import java.util.function.Function;
  *
  * @author Paul Campbell (pcampbell@kemitix.net)
  */
-final class LocalGitDB implements GitDB {
+final class LocalGitDBImpl implements GitDB, LocalGitDB {
 
     private static final String NOT_A_BARE_REPO = "Not a bare repo";
     private static final String ERROR_OPENING_REPOSITORY = "Error opening repository";
@@ -45,7 +48,7 @@ final class LocalGitDB implements GitDB {
 
     private final Function<Ref, GitDBBranch> branchInit;
 
-    private LocalGitDB(
+    private LocalGitDBImpl(
             final Repository repository,
             final String userName,
             final String userEmailAddress
@@ -53,31 +56,7 @@ final class LocalGitDB implements GitDB {
         this.repository = repository;
         this.userName = userName;
         this.userEmailAddress = userEmailAddress;
-        branchInit = GitDBBranch.init(this.repository, this.userName, this.userEmailAddress);
-    }
-
-    /**
-     * Create a new GitDB instance using the Git repo.
-     *
-     * @param dbDir            the path to instantiate the git repo in
-     * @param userName         the user name
-     * @param userEmailAddress the user email address
-     * @return a GitDB instance for the created local gitdb
-     */
-    static GitDB open(
-            final Path dbDir,
-            final String userName,
-            final String userEmailAddress
-    ) {
-        try {
-            return Optional.of(Git.open(dbDir.toFile()))
-                    .map(Git::getRepository)
-                    .filter(Repository::isBare)
-                    .map(repository -> new LocalGitDB(repository, userName, userEmailAddress))
-                    .orElseThrow(() -> new InvalidRepositoryException(NOT_A_BARE_REPO, dbDir));
-        } catch (IOException e) {
-            throw new InvalidRepositoryException(ERROR_OPENING_REPOSITORY, dbDir, e);
-        }
+        branchInit = GitDBBranchImpl.init(this.repository, this.userName, this.userEmailAddress);
     }
 
     /**
@@ -98,6 +77,30 @@ final class LocalGitDB implements GitDB {
         return open(dbDir, userName, userEmailAddress);
     }
 
+    /**
+     * Create a new GitDB instance using the Git repo.
+     *
+     * @param dbDir            the path to instantiate the git repo in
+     * @param userName         the user name
+     * @param userEmailAddress the user email address
+     * @return a GitDB instance for the created local gitdb
+     */
+    static GitDB open(
+            final Path dbDir,
+            final String userName,
+            final String userEmailAddress
+    ) {
+        try {
+            return Optional.of(Git.open(dbDir.toFile()))
+                    .map(Git::getRepository)
+                    .filter(Repository::isBare)
+                    .map(repository -> new LocalGitDBImpl(repository, userName, userEmailAddress))
+                    .orElseThrow(() -> new InvalidRepositoryException(NOT_A_BARE_REPO, dbDir));
+        } catch (IOException e) {
+            throw new InvalidRepositoryException(ERROR_OPENING_REPOSITORY, dbDir, e);
+        }
+    }
+
     @Override
     public Optional<GitDBBranch> branch(final String name) throws IOException {
         return Optional.ofNullable(repository.findRef(name)).map(branchInit);
diff --git a/src/main/java/net/kemitix/gitdb/ValueWriter.java b/src/main/java/net/kemitix/gitdb/impl/ValueWriter.java
similarity index 98%
rename from src/main/java/net/kemitix/gitdb/ValueWriter.java
rename to src/main/java/net/kemitix/gitdb/impl/ValueWriter.java
index 034dd29..f066551 100644
--- a/src/main/java/net/kemitix/gitdb/ValueWriter.java
+++ b/src/main/java/net/kemitix/gitdb/impl/ValueWriter.java
@@ -19,7 +19,7 @@
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-package net.kemitix.gitdb;
+package net.kemitix.gitdb.impl;
 
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
diff --git a/src/main/java/net/kemitix/gitdb/impl/package-info.java b/src/main/java/net/kemitix/gitdb/impl/package-info.java
new file mode 100644
index 0000000..e842481
--- /dev/null
+++ b/src/main/java/net/kemitix/gitdb/impl/package-info.java
@@ -0,0 +1,26 @@
+/*
+  The MIT License (MIT)
+
+  Copyright (c) 2018 Paul Campbell
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+  and associated documentation files (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+  and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all copies
+  or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
+  AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * GitDB - using git as a key/value database.
+ */
+
+package net.kemitix.gitdb.impl;
diff --git a/src/test/java/net/kemitix/gitdb/test/GitDBTest.java b/src/test/java/net/kemitix/gitdb/test/GitDBTest.java
index 2175365..99886fe 100644
--- a/src/test/java/net/kemitix/gitdb/test/GitDBTest.java
+++ b/src/test/java/net/kemitix/gitdb/test/GitDBTest.java
@@ -8,7 +8,6 @@ import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Repository;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.junit.jupiter.MockitoExtension;