diff --git a/protocol.md b/protocol.md
index c7238fd..ee4ac60 100644
--- a/protocol.md
+++ b/protocol.md
@@ -185,8 +185,18 @@ Communication between the master server and clients will be done over a WebSocke
  </thead>
  <tr>
   <td class="center">1</td>
-  <td>Client Key</td>
-  <td>Big Int</td>
+  <td>Server Name</td>
+  <td>Text</td>
+ </tr>
+ <tr>
+  <td class="center">2</td>
+  <td>License</td>
+  <td>Text</td>
+ </tr>
+ <tr>
+  <td class="center">3</td>
+  <td>Secret</td>
+  <td>Blob (512b)</td>
  </tr>
 </table>
 
@@ -472,9 +482,11 @@ TODO: MAKE THIS SECTION NOT LOOK LIKE SHIT
 0x02: COULD NOT PARSE KEY
 
 #### M -> S (ID 4)
-0x01: LICENSE DATA INCORRECT
+0x01: MAX AUTH ATTEMPTS REACHED
 
-0x02: LICENSE LIMIT REACHED
+0x02: LICENSE DATA INCORRECT
+
+0x03: LICENSE LIMIT REACHED
 
 ### Master / Client
 
diff --git a/server/src/db/database.hpp b/server/src/db/database.hpp
index ae33682..000cd94 100644
--- a/server/src/db/database.hpp
+++ b/server/src/db/database.hpp
@@ -14,6 +14,7 @@ namespace sosc {
 namespace db {
 
 class Query;
+typedef std::vector<Query*> QueryList;
 
 class ResultSet {
 public:
diff --git a/server/src/hosts/master.hpp b/server/src/hosts/master.hpp
index 1c75cdd..ef4a46b 100644
--- a/server/src/hosts/master.hpp
+++ b/server/src/hosts/master.hpp
@@ -10,6 +10,8 @@
 
 #include "../db/database.hpp"
 
+#include <vector>
+
 namespace sosc {
 /** MASTER -> CLIENT **/
     
@@ -36,7 +38,7 @@ protected:
 class MasterIntra {
 public:
     explicit MasterIntra(const IntraClient& client);
-    bool Process();
+    bool Process(const db::QueryList* queries);
 
     bool Close();
     bool Close(const Packet& message);
@@ -45,6 +47,9 @@ private:
     bool Authentication(Packet& pck);
     bool StatusUpdate(Packet& pck);
 
+    bool AuthenticationFailure
+        (const std::string& packetId, uint16_t errorCode);
+
     enum SlaveToMasterId {
         kInitAttempt = 1,
         kAuthentication,
@@ -66,13 +71,21 @@ private:
     int auth_attempts;
     const int MAX_AUTH_ATTEMPTS = 3;
     std::string license;
+
+    const db::QueryList* queries;
 };
 
 class MasterIntraPool : public Pool<MasterIntra> {
+public:
+    MasterIntraPool();
 protected:
     bool ProcessClient(MasterIntra& client) override {
-        return client.Process();
+        return client.Process(&this->queries);
     }
+
+    void Stop() override;
+private:
+    db::QueryList queries;
 };
 }
 
diff --git a/server/src/hosts/master_intra.cpp b/server/src/hosts/master_intra.cpp
index f128880..038d31b 100644
--- a/server/src/hosts/master_intra.cpp
+++ b/server/src/hosts/master_intra.cpp
@@ -1,5 +1,43 @@
 #include "master.hpp"
 #include "../db/database.hpp"
+#include <mutex>
+
+static struct {
+    std::mutex license_check_mtx;
+} _ctx;
+
+/** MASTERINTRAPOOL CODE **/
+
+sosc::MasterIntraPool::MasterIntraPool() {
+#define QRY_LICENSE_CHECK 0
+    this->queries.push_back(new db::Query(
+        "SELECT COUNT(*) FROM SERVER_LICENSES "
+        "WHERE KEY_ID = ? AND SECRET = ?"
+    ));
+
+#define QRY_LICENSE_LIMIT 1
+    this->queries.push_back(new db::Query(
+        "SELECT ALLOWANCE FROM SERVER_LICENSES WHERE KEY_ID = ?"
+    ));
+
+#define QRY_LICENSE_ACTIVE_COUNT 2
+    this->queries.push_back(new db::Query(
+        "SELECT COUNT(*) FROM SERVER_LIST WHERE LICENSE = ?"
+    , DB_USE_MEMORY));
+
+#define QRY_LICENSE_
+}
+
+void sosc::MasterIntraPool::Stop() {
+    Pool<MasterIntra>::Stop();
+
+    for(auto& query : this->queries) {
+        query->Close();
+        delete query;
+    }
+}
+
+/** MASTERINTRA CODE **/
 
 sosc::MasterIntra::MasterIntra(const IntraClient& client) {
     this->sock = client;
@@ -7,7 +45,7 @@ sosc::MasterIntra::MasterIntra(const IntraClient& client) {
     this->auth_attempts = 0;
 }
 
-bool sosc::MasterIntra::Process() {
+bool sosc::MasterIntra::Process(const db::QueryList* queries) {
     Packet pck;
     int status = this->sock.Receive(&pck);
     if(status == PCK_ERR)
@@ -15,6 +53,7 @@ bool sosc::MasterIntra::Process() {
     else if(status == PCK_MORE)
         return true;
 
+    this->queries = queries;
     switch(pck.GetId()) {
         case kInitAttempt:
             return this->InitAttempt(pck);
@@ -27,7 +66,8 @@ bool sosc::MasterIntra::Process() {
     }
 }
 
-bool sosc::MasterIntra::InitAttempt(sosc::Packet &pck) {
+bool sosc::MasterIntra::InitAttempt(sosc::Packet &pck)
+{
     if(!pck.Check(1, key.key_size_bytes))
         return this->Close(Packet(kEncryptionError, { "\x01" }));
 
@@ -38,24 +78,62 @@ bool sosc::MasterIntra::InitAttempt(sosc::Packet &pck) {
     this->sock.Send(response);
 }
 
-bool sosc::MasterIntra::Authentication(sosc::Packet &pck) {
+bool sosc::MasterIntra::Authentication(sosc::Packet &pck)
+{
     if(this->authed)
         return true;
 
-    if(!pck.Check(2, PCK_ANY, 512))
-        return this->Close(Packet(kNegativeAck, { "\x01" }));
+    std::string packetId = BYTESTR(kAuthentication);
+    if(!pck.Check(3, PCK_ANY, PCK_ANY, 512))
+        return this->Close();
 
-    db::Query  = db::Query::ScalarInt32(
-        "SELECT COUNT(*) FROM SERVER_LICENSES "
-        "WHERE KEY_ID = ? AND SECRET = ?"
-    );
+    db::Query* query = this->queries->at(QRY_LICENSE_CHECK);
+    query->Reset();
+    query->BindText(pck[1], 0);
+    query->BindBlob(pck[2], 1);
+    if(query->ScalarInt32() == 0)
+        return AuthenticationFailure(packetId, 2);
 
-    if(isValid > 0) {
+    _ctx.license_check_mtx.lock();
 
+    int limit;
+    query = this->queries->at(QRY_LICENSE_LIMIT);
+    query->Reset();
+    query->BindText(pck[1], 0);
+    if((limit = query->ScalarInt32()) != 0) {
+        query = this->queries->at(QRY_LICENSE_ACTIVE_COUNT);
+        query->Reset();
+        query->BindText(pck[1], 0);
+        if(query->ScalarInt32() < limit) {
+            _ctx.license_check_mtx.unlock();
+            return AuthenticationFailure(packetId, 3);
+        }
+    }
+
+
+    _ctx.license_check_mtx.unlock();
+
+    this->authed = true;
+    return true;
+}
+
+bool sosc::MasterIntra::AuthenticationFailure
+    (const std::string& packetId, uint16_t errorCode)
+{
+    if(++this->auth_attempts < MAX_AUTH_ATTEMPTS) {
+        this->sock.Send(
+            Packet(kNegativeAck, { packetId , net::htonv(errorCode) })
+        );
+        return true;
+    } else {
+        return this->Close(
+            Packet(kNegativeAck, { packetId, net::htonv<uint16_t>(1) })
+        );
     }
 }
 
-bool sosc::MasterIntra::StatusUpdate(sosc::Packet &pck) {
+bool sosc::MasterIntra::StatusUpdate(sosc::Packet &pck)
+{
 
 }
 
@@ -67,4 +145,4 @@ bool sosc::MasterIntra::Close() {
 bool sosc::MasterIntra::Close(const Packet &message) {
     this->sock.Send(message);
     this->Close();
-}
+}
\ No newline at end of file
diff --git a/server/src/sock/pool.hpp b/server/src/sock/pool.hpp
index 89cac5c..fb8c756 100644
--- a/server/src/sock/pool.hpp
+++ b/server/src/sock/pool.hpp
@@ -40,7 +40,7 @@ public:
         return this->is_open;
     }
     
-    void Stop();
+    virtual void Stop();
 protected:
     virtual bool ProcessClient(T& client) = 0;
 private:
diff --git a/server/src/utils/string.hpp b/server/src/utils/string.hpp
index 86f6528..8a279c1 100644
--- a/server/src/utils/string.hpp
+++ b/server/src/utils/string.hpp
@@ -10,6 +10,10 @@
 #undef TOSTR
 #define TOSTR(X) std::to_string(X)
 
+#undef bytestr
+#undef BYTESTR
+#define BYTESTR(X) std::string(1, X)
+
 namespace sosc {
 namespace str {    
 std::string  trim (std::string  str);