diff --git a/src/git.xdrm.io/schastsp/client/client.go b/src/git.xdrm.io/schastsp/client/client.go
new file mode 100644
index 0000000..7920ea1
--- /dev/null
+++ b/src/git.xdrm.io/schastsp/client/client.go
@@ -0,0 +1,146 @@
+package client;
+
+import (
+	"git.xdrm.io/schastsp/context"
+	"git.xdrm.io/schastsp/client/keyset"
+)
+
+
+/* (1) Structure
+---------------------------------------------------------*/
+type T struct {
+	ctx      *context.T // shared context
+	key      *keyset.T; // current key
+	sync     *keyset.T; // next bufferised key
+	consumed bool;      // true if 'key' must be renewed (with 'sync')
+	fkey     *config    // key file management
+	fsync    *config    // sync file management
+}
+
+
+/* (2) Constructor
+*
+* @ctx<context.T>					Shared context
+* @saveDir<string>					Configuration path
+*
+---------------------------------------------------------*/
+func New(ctx *context.T, saveDir string) (*T, error) {
+
+	var err error;
+
+	inst := new(T);
+
+	/* (1) Store context */
+	inst.ctx = ctx;
+
+
+	/* (2) Get file management for KEY */
+	inst.fkey, err = Config(saveDir, "key");
+	if err != nil { return nil, err }
+
+	/* (3) Get file management for SYNC */
+	inst.fsync, err = Config(saveDir, "sync");
+	if err != nil { return nil, err }
+
+	/* (4) Init KEY */
+	inst.key = nil
+
+	/* (5) Init SYNC */
+	inst.sync = nil
+
+	/* (6) Restore from config */
+	inst.Update();
+
+	return inst, nil;
+
+}
+
+
+
+/* (1) Updates 'key' and 'sync' with files (reads or write)
+*
+---------------------------------------------------------*/
+func (c T) Update(){
+
+	/* (1) Restore (both are NIL)
+	---------------------------------------------------------*/
+	if c.key == nil && c.sync == nil {
+
+		/* (1) Fetch key */
+		keyReader := c.fkey.Reader();
+
+		if keyReader != nil {
+
+			defer keyReader.Close();
+
+			c.key, _ = keyset.Create(c.ctx);
+
+			c.key.Fetch(keyReader);
+
+		}
+
+		/* (2) Fetch sync */
+		syncReader := c.fsync.Reader();
+
+		if syncReader != nil {
+
+			defer syncReader.Close();
+
+			c.sync, _ = keyset.Create(c.ctx);
+
+			c.sync.Fetch(syncReader);
+
+		}
+
+		/* (3) Exit if no error */
+		if c.key != nil && c.sync != nil {
+			return;
+		}
+
+	}
+
+
+
+	/* (2) Manage if no config
+	---------------------------------------------------------*/
+	if c.key == nil{
+		c.key, _ = keyset.Create(c.ctx);
+	}
+
+	if c.sync == nil{
+		c.sync, _ = keyset.Create(c.ctx);
+	}
+
+
+
+	/* (3) Store current value
+	---------------------------------------------------------*/
+	/* (1) Store key */
+	c.key, _ = keyset.Create(c.ctx);
+
+	keyWriter := c.fkey.Writer();
+
+	if keyWriter != nil {
+
+		defer keyWriter.Close();
+
+		c.key, _ = keyset.Create(c.ctx);
+
+		c.key.Store(keyWriter);
+	}
+
+	/* (2) Store sync */
+	c.sync, _ = keyset.Create(c.ctx);
+
+	syncWriter := c.fsync.Writer();
+
+	if syncWriter != nil {
+
+		defer syncWriter.Close();
+
+		c.sync, _ = keyset.Create(c.ctx);
+
+		c.sync.Store(syncWriter);
+	}
+
+}
\ No newline at end of file