diff --git a/src/knowledge_base.cpp b/src/knowledge_base.cpp
index ce47572..b248b66 100644
--- a/src/knowledge_base.cpp
+++ b/src/knowledge_base.cpp
@@ -9,11 +9,6 @@
 #include <filesystem>
 #include <iostream>
 
-obelisk::KnowledgeBase::KnowledgeBase(const char* filename)
-{
-    KnowledgeBase(filename, DEFAULT_FLAGS);
-}
-
 obelisk::KnowledgeBase::KnowledgeBase(const char* filename, int flags)
 {
     filename_ = std::move(filename);
@@ -66,6 +61,33 @@ void obelisk::KnowledgeBase::createTable(std::function<const char*()> function)
     }
 }
 
+int obelisk::KnowledgeBase::addEntities(std::vector<obelisk::Entity>& entities)
+{
+    for (auto& entity : entities)
+    {
+        entity.insertEntity(dbConnection_);
+    }
+    return 0;
+}
+
+int obelisk::KnowledgeBase::addVerbs(std::vector<obelisk::Verb>& verbs)
+{
+    for (auto& verb : verbs)
+    {
+        verb.insertVerb(dbConnection_);
+    }
+    return 0;
+}
+
+int obelisk::KnowledgeBase::addFacts(std::vector<obelisk::Fact>& facts)
+{
+    for (auto& fact : facts)
+    {
+        fact.insertFact(dbConnection_);
+    }
+    return 0;
+}
+
 // TODO: log files?
 void obelisk::KnowledgeBase::logSqliteError(int result)
 {
diff --git a/src/knowledge_base.h b/src/knowledge_base.h
index 52e742f..4e79c74 100644
--- a/src/knowledge_base.h
+++ b/src/knowledge_base.h
@@ -1,10 +1,15 @@
 #ifndef OBELISK_KNOWLEDGE_BASE_H
 #define OBELISK_KNOWLEDGE_BASE_H
 
+#include "models/entity.h"
+#include "models/fact.h"
+#include "models/verb.h"
+
 #include <sqlite3.h>
 
 #include <functional>
 #include <iostream>
+#include <memory>
 #include <string>
 
 namespace obelisk
@@ -22,16 +27,19 @@ namespace obelisk
             void createTable(std::function<const char*()> function);
 
         public:
-            KnowledgeBase(const char* filename);
             KnowledgeBase(const char* filename, int flags);
+
+            KnowledgeBase(const char* filename) :
+                KnowledgeBase(filename,
+                    SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE)
+            {
+            }
+
             ~KnowledgeBase();
 
-            template<typename T, typename U>
-            int addFacts(std::string verb, T leftEntities, U rightEntities);
-            // TODO: add parameter for fact
-            template<typename T, typename U>
-            int addRules(std::string verb, T leftEntities, U rightEntities);
-            template<typename T, typename U> int addActions();
+            int addEntities(std::vector<obelisk::Entity>& entities);
+            int addVerbs(std::vector<obelisk::Verb>& verbs);
+            int addFacts(std::vector<obelisk::Fact>& facts);
 
             void getDouble(double& result, float var1, float var2);
             void getFloat(float& result1, float& result2, double var);
diff --git a/src/models/action.cpp b/src/models/action.cpp
index 620b6e6..bb6ed06 100644
--- a/src/models/action.cpp
+++ b/src/models/action.cpp
@@ -11,7 +11,7 @@ const char* obelisk::Action::createTable()
     )";
 }
 
-int obelisk::Action::getId()
+int& obelisk::Action::getId()
 {
     return id_;
 }
@@ -21,7 +21,7 @@ void obelisk::Action::setId(int id)
     id_ = id;
 }
 
-std::string obelisk::Action::getName()
+std::string& obelisk::Action::getName()
 {
     return name_;
 }
diff --git a/src/models/action.h b/src/models/action.h
index d24ba8c..7940f2b 100644
--- a/src/models/action.h
+++ b/src/models/action.h
@@ -38,10 +38,10 @@ namespace obelisk
 
             static const char* createTable();
 
-            int getId();
+            int& getId();
             void setId(int id);
 
-            std::string getName();
+            std::string& getName();
             void setName(std::string name);
     };
 } // namespace obelisk
diff --git a/src/models/entity.cpp b/src/models/entity.cpp
index 3345e47..1a4fe78 100644
--- a/src/models/entity.cpp
+++ b/src/models/entity.cpp
@@ -11,7 +11,116 @@ const char* obelisk::Entity::createTable()
     )";
 }
 
-int obelisk::Entity::getId()
+obelisk::Entity obelisk::Entity::selectEntity(sqlite3* dbConnection,
+    std::string name)
+{
+    // TODO: check if database is open
+    sqlite3_stmt* ppStmt = nullptr;
+    const char* pzTail   = nullptr;
+
+    auto result = sqlite3_prepare_v2(dbConnection,
+        "SELECT id, name FROM entity WHERE name=?;",
+        -1,
+        &ppStmt,
+        &pzTail);
+    if (result != SQLITE_OK)
+    {
+        // TODO: something went wrong throw an error
+    }
+
+    if (pzTail != nullptr)
+    {
+        // TODO: Something was not used... throw an error
+    }
+
+    result = sqlite3_bind_text(ppStmt, 1, name.c_str(), -1, SQLITE_TRANSIENT);
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_step(ppStmt);
+    if (result != SQLITE_DONE)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    if (result == SQLITE_ROW)
+    {
+        auto id = sqlite3_column_int(ppStmt, 0);
+        std::string name((char*) sqlite3_column_text(ppStmt, 1));
+
+        result = sqlite3_finalize(ppStmt);
+        if (result != SQLITE_OK)
+        {
+            // TODO: Something is wrong... throw an error
+        }
+        return Entity(id, name);
+    }
+    else
+    {
+        result = sqlite3_finalize(ppStmt);
+        if (result != SQLITE_OK)
+        {
+            // TODO: Something is wrong... throw an error
+        }
+        return Entity();
+    }
+}
+
+int obelisk::Entity::insertEntity(sqlite3* dbConnection)
+{
+    // TODO: check if database is open
+
+    if (selectEntity(dbConnection, getName()).getId() != 0)
+    {
+        // TODO: already exists in database, throw an error? Or skip past it?
+        return -1;
+    }
+
+    sqlite3_stmt* ppStmt = nullptr;
+    const char* pzTail   = nullptr;
+
+    auto result = sqlite3_prepare_v2(dbConnection,
+        "INSERT INTO entity (name) VALUES (?);",
+        -1,
+        &ppStmt,
+        &pzTail);
+    if (result != SQLITE_OK)
+    {
+        // TODO: something went wrong throw an error
+    }
+
+    if (pzTail != nullptr)
+    {
+        // TODO: Something was not used... throw an error
+    }
+
+    result
+        = sqlite3_bind_text(ppStmt, 1, getName().c_str(), -1, SQLITE_TRANSIENT);
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_step(ppStmt);
+    if (result != SQLITE_DONE)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    setId((int) sqlite3_last_insert_rowid(dbConnection));
+
+    result = sqlite3_finalize(ppStmt);
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    return 0;
+}
+
+int& obelisk::Entity::getId()
 {
     return id_;
 }
@@ -21,7 +130,7 @@ void obelisk::Entity::setId(int id)
     id_ = id;
 }
 
-std::string obelisk::Entity::getName()
+std::string& obelisk::Entity::getName()
 {
     return name_;
 }
diff --git a/src/models/entity.h b/src/models/entity.h
index b73f7c9..f83337c 100644
--- a/src/models/entity.h
+++ b/src/models/entity.h
@@ -1,6 +1,8 @@
 #ifndef OBELISK_MODELS_ENTITY_H
 #define OBELISK_MODELS_ENTITY_H
 
+#include <sqlite3.h>
+
 #include <string>
 
 namespace obelisk
@@ -38,11 +40,14 @@ namespace obelisk
 
             static const char* createTable();
 
-            int getId();
+            int& getId();
             void setId(int id);
 
-            std::string getName();
+            std::string& getName();
             void setName(std::string name);
+
+            Entity selectEntity(sqlite3* dbConnection, std::string name);
+            int insertEntity(sqlite3* dbConnection);
     };
 } // namespace obelisk
 
diff --git a/src/models/fact.cpp b/src/models/fact.cpp
index 132c80b..6a02b97 100644
--- a/src/models/fact.cpp
+++ b/src/models/fact.cpp
@@ -16,7 +16,152 @@ const char* obelisk::Fact::createTable()
     )";
 }
 
-int obelisk::Fact::getId()
+obelisk::Fact obelisk::Fact::selectFact(sqlite3* dbConnection,
+    int idLeftEntity,
+    int idRightEntity,
+    int idVerb)
+{
+    // TODO: check if database is open
+
+    sqlite3_stmt* ppStmt = nullptr;
+    const char* pzTail   = nullptr;
+
+    auto result = sqlite3_prepare_v2(dbConnection,
+        "SELECT id, left_entity, right_entity, verb FROM fact WHERE (left_entity=? AND right_entity=? AND verb=?);",
+        -1,
+        &ppStmt,
+        &pzTail);
+    if (result != SQLITE_OK)
+    {
+        // TODO: something went wrong throw an error
+    }
+
+    if (pzTail != nullptr)
+    {
+        // TODO: Something was not used... throw an error
+    }
+
+    result = sqlite3_bind_int(ppStmt, 1, getLeftEntity().getId());
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_bind_int(ppStmt, 2, getRightEntity().getId());
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_bind_int(ppStmt, 3, getVerb().getId());
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_step(ppStmt);
+    if (result != SQLITE_DONE)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    if (result == SQLITE_ROW)
+    {
+        auto id          = sqlite3_column_int(ppStmt, 0);
+        auto leftEntity  = sqlite3_column_int(ppStmt, 1);
+        auto rightEntity = sqlite3_column_int(ppStmt, 2);
+        auto verb        = sqlite3_column_int(ppStmt, 3);
+
+        result = sqlite3_finalize(ppStmt);
+        if (result != SQLITE_OK)
+        {
+            // TODO: Something is wrong... throw an error
+        }
+        return Fact(id, leftEntity, rightEntity, verb);
+    }
+    else
+    {
+        result = sqlite3_finalize(ppStmt);
+        if (result != SQLITE_OK)
+        {
+            // TODO: Something is wrong... throw an error
+        }
+        return Fact();
+    }
+}
+
+int obelisk::Fact::insertFact(sqlite3* dbConnection)
+{
+    // TODO: make sure database is open
+
+    // check if the fact id exists, based on the ids of the entities and verb
+    if (selectFact(dbConnection,
+            getLeftEntity().getId(),
+            getRightEntity().getId(),
+            getVerb().getId())
+            .getId()
+        != 0)
+    {
+        // TODO: Verb is already in database, throw an error? Or just skip it?
+        return -1;
+    }
+
+    // TODO: verify that verbId, leftEntityId, and rightEntityId are not 0
+
+    sqlite3_stmt* ppStmt = nullptr;
+    const char* pzTail   = nullptr;
+
+    auto result = sqlite3_prepare_v2(dbConnection,
+        "INSERT INTO fact (left_entity, right_entity, verb) VALUES (?, ?, ?);",
+        -1,
+        &ppStmt,
+        &pzTail);
+    if (result != SQLITE_OK)
+    {
+        // TODO: something went wrong throw an error
+    }
+
+    if (pzTail != nullptr)
+    {
+        // TODO: Something was not used... throw an error
+    }
+
+    result = sqlite3_bind_int(ppStmt, 1, getLeftEntity().getId());
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_bind_int(ppStmt, 2, getRightEntity().getId());
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_bind_int(ppStmt, 3, getVerb().getId());
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_step(ppStmt);
+    if (result != SQLITE_DONE)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    setId((int) sqlite3_last_insert_rowid(dbConnection));
+
+    result = sqlite3_finalize(ppStmt);
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    return 0;
+}
+
+int& obelisk::Fact::getId()
 {
     return id_;
 }
@@ -26,7 +171,7 @@ void obelisk::Fact::setId(int id)
     id_ = id;
 }
 
-obelisk::Entity obelisk::Fact::getLeftEntity()
+obelisk::Entity& obelisk::Fact::getLeftEntity()
 {
     return leftEntity_;
 }
@@ -36,7 +181,7 @@ void obelisk::Fact::setLeftEntity(obelisk::Entity leftEntity)
     leftEntity_ = leftEntity;
 }
 
-obelisk::Entity obelisk::Fact::getRightEntity()
+obelisk::Entity& obelisk::Fact::getRightEntity()
 {
     return rightEntity_;
 }
@@ -46,7 +191,7 @@ void obelisk::Fact::setRightEntity(obelisk::Entity rightEntity)
     rightEntity_ = rightEntity;
 }
 
-obelisk::Verb obelisk::Fact::getVerb()
+obelisk::Verb& obelisk::Fact::getVerb()
 {
     return verb_;
 }
diff --git a/src/models/fact.h b/src/models/fact.h
index 6553058..3fc5987 100644
--- a/src/models/fact.h
+++ b/src/models/fact.h
@@ -2,6 +2,7 @@
 #define OBELISK_MODELS_FACT_H
 
 #include "models/entity.h"
+#include "models/fact.h"
 #include "models/verb.h"
 
 #include <string>
@@ -56,17 +57,24 @@ namespace obelisk
 
             static const char* createTable();
 
-            int getId();
+            int& getId();
             void setId(int id);
 
-            obelisk::Entity getLeftEntity();
+            Entity& getLeftEntity();
             void setLeftEntity(obelisk::Entity leftEntity);
 
-            obelisk::Entity getRightEntity();
+            Entity& getRightEntity();
             void setRightEntity(obelisk::Entity leftEntity);
 
-            obelisk::Verb getVerb();
+            Verb& getVerb();
             void setVerb(obelisk::Verb verb);
+
+            Fact selectFact(sqlite3* dbConnection,
+                int idLeftEntity,
+                int idRightEntity,
+                int idVerb);
+
+            int insertFact(sqlite3* dbConnection);
     };
 } // namespace obelisk
 
diff --git a/src/models/rule.cpp b/src/models/rule.cpp
index 3282743..e9bde88 100644
--- a/src/models/rule.cpp
+++ b/src/models/rule.cpp
@@ -14,7 +14,7 @@ const char* obelisk::Rule::createTable()
     )";
 }
 
-int obelisk::Rule::getId()
+int& obelisk::Rule::getId()
 {
     return id_;
 }
@@ -24,7 +24,7 @@ void obelisk::Rule::setId(int id)
     id_ = id;
 }
 
-obelisk::Fact obelisk::Rule::getFact()
+obelisk::Fact& obelisk::Rule::getFact()
 {
     return fact_;
 }
@@ -34,7 +34,7 @@ void obelisk::Rule::setFact(obelisk::Fact fact)
     fact_ = fact;
 }
 
-obelisk::Fact obelisk::Rule::getReason()
+obelisk::Fact& obelisk::Rule::getReason()
 {
     return reason_;
 }
diff --git a/src/models/rule.h b/src/models/rule.h
index f120896..ae75a85 100644
--- a/src/models/rule.h
+++ b/src/models/rule.h
@@ -45,13 +45,13 @@ namespace obelisk
 
             static const char* createTable();
 
-            int getId();
+            int& getId();
             void setId(int id);
 
-            obelisk::Fact getFact();
+            obelisk::Fact& getFact();
             void setFact(obelisk::Fact fact);
 
-            obelisk::Fact getReason();
+            obelisk::Fact& getReason();
             void setReason(obelisk::Fact reason);
     };
 } // namespace obelisk
diff --git a/src/models/suggest_action.cpp b/src/models/suggest_action.cpp
index 1b6c6e6..929aa5b 100644
--- a/src/models/suggest_action.cpp
+++ b/src/models/suggest_action.cpp
@@ -16,7 +16,7 @@ const char* obelisk::SuggestAction::createTable()
     )";
 }
 
-int obelisk::SuggestAction::getId()
+int& obelisk::SuggestAction::getId()
 {
     return id_;
 }
@@ -26,7 +26,7 @@ void obelisk::SuggestAction::setId(int id)
     id_ = id;
 }
 
-obelisk::Fact obelisk::SuggestAction::getFact()
+obelisk::Fact& obelisk::SuggestAction::getFact()
 {
     return fact_;
 }
@@ -36,7 +36,7 @@ void obelisk::SuggestAction::setFact(obelisk::Fact fact)
     fact_ = fact;
 }
 
-obelisk::Action obelisk::SuggestAction::getTrueAction()
+obelisk::Action& obelisk::SuggestAction::getTrueAction()
 {
     return trueAction_;
 }
@@ -46,7 +46,7 @@ void obelisk::SuggestAction::setTrueAction(obelisk::Action trueAction)
     trueAction_ = trueAction;
 }
 
-obelisk::Action obelisk::SuggestAction::getFalseAction()
+obelisk::Action& obelisk::SuggestAction::getFalseAction()
 {
     return falseAction_;
 }
diff --git a/src/models/suggest_action.h b/src/models/suggest_action.h
index 6b33e88..2f680e4 100644
--- a/src/models/suggest_action.h
+++ b/src/models/suggest_action.h
@@ -56,16 +56,16 @@ namespace obelisk
 
             static const char* createTable();
 
-            int getId();
+            int& getId();
             void setId(int id);
 
-            obelisk::Fact getFact();
+            obelisk::Fact& getFact();
             void setFact(obelisk::Fact fact);
 
-            obelisk::Action getTrueAction();
+            obelisk::Action& getTrueAction();
             void setTrueAction(obelisk::Action trueAction);
 
-            obelisk::Action getFalseAction();
+            obelisk::Action& getFalseAction();
             void setFalseAction(obelisk::Action falseAction);
     };
 } // namespace obelisk
diff --git a/src/models/verb.cpp b/src/models/verb.cpp
index ac9aeb9..e3820fb 100644
--- a/src/models/verb.cpp
+++ b/src/models/verb.cpp
@@ -1,5 +1,7 @@
 #include "models/verb.h"
 
+#include <iostream>
+
 const char* obelisk::Verb::createTable()
 {
     return R"(
@@ -11,7 +13,116 @@ const char* obelisk::Verb::createTable()
     )";
 }
 
-int obelisk::Verb::getId()
+obelisk::Verb obelisk::Verb::selectVerb(sqlite3* dbConnection, std::string name)
+{
+    // TODO: check if database is open
+
+    sqlite3_stmt* ppStmt = nullptr;
+    const char* pzTail   = nullptr;
+
+    auto result = sqlite3_prepare_v2(dbConnection,
+        "SELECT id, name FROM verb WHERE name=?;",
+        -1,
+        &ppStmt,
+        &pzTail);
+    if (result != SQLITE_OK)
+    {
+        // TODO: something went wrong throw an error
+    }
+
+    if (pzTail != nullptr)
+    {
+        // TODO: Something was not used... throw an error
+    }
+
+    result = sqlite3_bind_text(ppStmt, 1, name.c_str(), -1, SQLITE_TRANSIENT);
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_step(ppStmt);
+    if (result != SQLITE_DONE)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    if (result == SQLITE_ROW)
+    {
+        auto id = sqlite3_column_int(ppStmt, 0);
+        std::string name((char*) sqlite3_column_text(ppStmt, 1));
+
+        result = sqlite3_finalize(ppStmt);
+        if (result != SQLITE_OK)
+        {
+            // TODO: Something is wrong... throw an error
+        }
+        return Verb(id, name);
+    }
+    else
+    {
+        result = sqlite3_finalize(ppStmt);
+        if (result != SQLITE_OK)
+        {
+            // TODO: Something is wrong... throw an error
+        }
+        return Verb();
+    }
+}
+
+int obelisk::Verb::insertVerb(sqlite3* dbConnection)
+{
+    // TODO: make sure database is open
+
+    if (selectVerb(dbConnection, getName()).getId() != 0)
+    {
+        // TODO: Verb is already in database, throw an error? Or just skip it?
+        return -1;
+    }
+
+    sqlite3_stmt* ppStmt = nullptr;
+    const char* pzTail   = nullptr;
+
+    auto result = sqlite3_prepare_v2(dbConnection,
+        "INSERT INTO verb (name) VALUES (?);",
+        -1,
+        &ppStmt,
+        &pzTail);
+    if (result != SQLITE_OK)
+    {
+        // TODO: something went wrong throw an error
+    }
+
+    if (pzTail != nullptr)
+    {
+        // TODO: Something was not used... throw an error
+    }
+
+    result
+        = sqlite3_bind_text(ppStmt, 1, getName().c_str(), -1, SQLITE_TRANSIENT);
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    result = sqlite3_step(ppStmt);
+    if (result != SQLITE_DONE)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    setId((int) sqlite3_last_insert_rowid(dbConnection));
+
+    result = sqlite3_finalize(ppStmt);
+    if (result != SQLITE_OK)
+    {
+        // TODO: Something is wrong... throw an error
+    }
+
+    return 0;
+}
+
+int& obelisk::Verb::getId()
 {
     return id_;
 }
@@ -21,7 +132,7 @@ void obelisk::Verb::setId(int id)
     id_ = id;
 }
 
-std::string obelisk::Verb::getName()
+std::string& obelisk::Verb::getName()
 {
     return name_;
 }
diff --git a/src/models/verb.h b/src/models/verb.h
index dfb3a6e..8e8d241 100644
--- a/src/models/verb.h
+++ b/src/models/verb.h
@@ -1,6 +1,8 @@
 #ifndef OBELISK_MODELS_VERB_H
 #define OBELISK_MODELS_VERB_H
 
+#include <sqlite3.h>
+
 #include <string>
 
 namespace obelisk
@@ -38,11 +40,14 @@ namespace obelisk
 
             static const char* createTable();
 
-            int getId();
+            int& getId();
             void setId(int id);
 
-            std::string getName();
+            std::string& getName();
             void setName(std::string name);
+
+            Verb selectVerb(sqlite3* dbConnection, std::string name);
+            int insertVerb(sqlite3* dbConnection);
     };
 } // namespace obelisk
 
diff --git a/src/obelisk.cpp b/src/obelisk.cpp
index 47c695a..7586d95 100644
--- a/src/obelisk.cpp
+++ b/src/obelisk.cpp
@@ -8,9 +8,21 @@
 #include <limits>
 #include <memory>
 
-static void mainLoop()
+static int mainLoop()
 {
     auto parser = std::unique_ptr<obelisk::Parser> {new obelisk::Parser()};
+    std::unique_ptr<obelisk::KnowledgeBase> kb;
+
+    try
+    {
+        kb = std::unique_ptr<obelisk::KnowledgeBase> {
+            new obelisk::KnowledgeBase("cromer.kb")};
+    }
+    catch (obelisk::KnowledgeBaseException& exception)
+    {
+        std::cout << exception.what() << std::endl;
+        return EXIT_FAILURE;
+    }
 
     // Prime the first token.
     fprintf(stderr, "ready> ");
@@ -22,7 +34,7 @@ static void mainLoop()
         switch (parser->getCurrentToken())
         {
             case obelisk::Lexer::kTokenEof :
-                return;
+                return EXIT_SUCCESS;
             case ';' : // ignore top-level semicolons.
                 std::cout << "Identifier: "
                           << parser->getLexer()->getIdentifier() << std::endl;
@@ -31,19 +43,21 @@ static void mainLoop()
                 parser->getNextToken();
                 break;
             case obelisk::Lexer::kTokenFact :
-                // parser->handleFactFunction();
+                parser->handleFact(kb);
                 break;
             case obelisk::Lexer::kTokenRule :
-                // parser->handleRuleFunction();
+                // parser->handleRule();
                 break;
             case obelisk::Lexer::kTokenAction :
-                // parser->handleActionFunction();
+                // parser->handleAction();
                 break;
             default :
                 parser->getNextToken();
                 break;
         }
     }
+
+    return EXIT_SUCCESS;
 }
 
 int main(int argc, char** argv)
@@ -79,28 +93,5 @@ int main(int argc, char** argv)
         return EXIT_FAILURE;
     }*/
 
-    try
-    {
-        auto kb = std::unique_ptr<obelisk::KnowledgeBase> {
-            new obelisk::KnowledgeBase("cromer.kb")};
-
-        /*std::vector<std::string> leftObjects;
-        std::vector<std::string> rightObjects;
-        leftObjects.push_back("chris");
-        leftObjects.push_back("martin");
-
-        rightObjects.push_back("happy");
-        rightObjects.push_back("smart");
-
-        kb->addFacts("is", leftObjects, rightObjects);*/
-    }
-    catch (obelisk::KnowledgeBaseException& exception)
-    {
-        std::cout << exception.what() << std::endl;
-        return EXIT_FAILURE;
-    }
-
-    mainLoop();
-
-    return EXIT_SUCCESS;
+    return mainLoop();
 }
diff --git a/src/obelisk.h b/src/obelisk.h
index d964df7..47cbdd0 100644
--- a/src/obelisk.h
+++ b/src/obelisk.h
@@ -1 +1 @@
-static void mainLoop();
+static int mainLoop();
diff --git a/src/parser.cpp b/src/parser.cpp
index 9ef3080..339581d 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -1,6 +1,9 @@
 #include "ast/call_expression_ast.h"
 #include "ast/number_expression_ast.h"
 #include "ast/variable_expression_ast.h"
+#include "models/entity.h"
+#include "models/fact.h"
+#include "models/verb.h"
 #include "parser.h"
 
 #include <memory>
@@ -212,17 +215,19 @@ std::unique_ptr<obelisk::PrototypeAST> obelisk::Parser::parseExtern()
     return parsePrototype();
 }
 
+//action("martin" is "dangerous" then "avoid" or "ignore");
 std::unique_ptr<obelisk::ExpressionAST> obelisk::Parser::parseAction()
 {
 }
 
+//rule("chris" and "martin" is "happy" if "chris" plays "playstation");
 std::unique_ptr<obelisk::ExpressionAST> obelisk::Parser::parseRule()
 {
 }
 
 // fact("chris cromer" and "martin" and "Isabella" can "program" and "speak english");
 // fact("" and "martin")
-std::unique_ptr<obelisk::ExpressionAST> obelisk::Parser::parseFact()
+void obelisk::Parser::parseFact(std::vector<obelisk::Fact>& facts)
 {
     std::stack<char> syntax;
 
@@ -329,18 +334,68 @@ std::unique_ptr<obelisk::ExpressionAST> obelisk::Parser::parseFact()
         }
     }
 
-    return nullptr;
+    for (auto& leftEntity : leftEntities)
+    {
+        for (auto& rightEntity : rightEntities)
+        {
+            facts.push_back(obelisk::Fact(obelisk::Entity(leftEntity),
+                obelisk::Entity(rightEntity),
+                obelisk::Verb(verb)));
+        }
+    }
 }
 
-void obelisk::Parser::handleAction()
+void obelisk::Parser::handleAction(std::unique_ptr<obelisk::KnowledgeBase>& kb)
 {
 }
 
-void obelisk::Parser::handleRule()
+void obelisk::Parser::handleRule(std::unique_ptr<obelisk::KnowledgeBase>& kb)
 {
 }
 
-void obelisk::Parser::handleFact()
+void obelisk::Parser::handleFact(std::unique_ptr<obelisk::KnowledgeBase>& kb)
 {
-    parseFact();
+    std::vector<obelisk::Fact> facts;
+    parseFact(facts);
+
+    int verbId = 0;
+    for (auto& fact : facts)
+    {
+        // TODO: doesn't work after first insert
+        std::vector<obelisk::Entity> entities {fact.getLeftEntity()};
+        kb->addEntities(entities);
+        fact.setLeftEntity(entities.front());
+
+        entities = {fact.getRightEntity()};
+        kb->addEntities(entities);
+        fact.setRightEntity(entities.front());
+
+        if (verbId == 0)
+        {
+            std::vector<obelisk::Verb> verbs = {fact.getVerb()};
+            kb->addVerbs(verbs);
+            if (verbs.front().getId() != 0)
+            {
+                // The verb was inserted
+                fact.setVerb(verbs.front());
+                verbId = fact.getVerb().getId();
+            }
+            else
+            {
+                // The verb is already already in the knowledge base
+                // TODO: SELECT the verb and save it into verbId
+            }
+        }
+        else
+        {
+            fact.getVerb().setId(verbId);
+        }
+
+        // INSERT INTO fact
+        std::vector<obelisk::Fact> facts {fact};
+        kb->addFacts(facts);
+        fact = facts.front();
+    }
 }
+
+// fact("chris cromer" and "martin" and "Isabella" can "program" and "speak english");
diff --git a/src/parser.h b/src/parser.h
index e020821..a71358e 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -4,7 +4,9 @@
 #include "ast/expression_ast.h"
 #include "ast/function_ast.h"
 #include "ast/prototype_ast.h"
+#include "knowledge_base.h"
 #include "lexer.h"
+#include "models/fact.h"
 
 #include <memory>
 
@@ -34,7 +36,7 @@ namespace obelisk
             std::unique_ptr<obelisk::PrototypeAST> parseExtern();
             std::unique_ptr<obelisk::ExpressionAST> parseAction();
             std::unique_ptr<obelisk::ExpressionAST> parseRule();
-            std::unique_ptr<obelisk::ExpressionAST> parseFact();
+            void parseFact(std::vector<obelisk::Fact>& facts);
 
         public:
             Parser();
@@ -48,9 +50,9 @@ namespace obelisk
             void handleDefinition();
             void handleExtern();
             void handleTopLevelExpression();
-            void handleAction();
-            void handleRule();
-            void handleFact();
+            void handleAction(std::unique_ptr<obelisk::KnowledgeBase>& kb);
+            void handleRule(std::unique_ptr<obelisk::KnowledgeBase>& kb);
+            void handleFact(std::unique_ptr<obelisk::KnowledgeBase>& kb);
     };
 
     class ParserException : public std::exception