diff --git a/src/api_data/conversation_message_api.rs b/src/api_data/conversation_message_api.rs
index 055638b..99e68d3 100644
--- a/src/api_data/conversation_message_api.rs
+++ b/src/api_data/conversation_message_api.rs
@@ -5,31 +5,86 @@
 //! @author Pierre HUBERT
 
 use serde::Serialize;
+use serde_json::Value;
 
-use crate::data::conversation_message::ConversationMessage;
+use crate::data::conversation_message::{ConversationMessage, ConversationServerMessageType};
 use crate::utils::user_data_utils::user_data_url;
 
 #[derive(Serialize)]
-#[allow(non_snake_case)]
+struct ConversationMessageFileAPI {
+    url: String,
+    size: u64,
+    name: String,
+    thumbnail: Option<String>,
+    r#type: String,
+}
+
+#[derive(Serialize)]
 pub struct ConversationMessageAPI {
-    ID: u64,
-    convID: u64,
-    ID_user: u64,
+    id: u64,
+    conv_id: u64,
+    user_id: Option<u64>,
     time_insert: u64,
-    message: String,
-    image_path: Option<String>,
+    message: Option<String>,
+    file: Option<ConversationMessageFileAPI>,
+    server_message: Option<serde_json::Value>,
 }
 
 impl ConversationMessageAPI {
     /// Turn a conversation message into an API entry
     pub fn new(msg: &ConversationMessage) -> ConversationMessageAPI {
+        let file = match &msg.file {
+            None => None,
+            Some(file) => Some(ConversationMessageFileAPI {
+                url: user_data_url(&file.path.clone()),
+                size: file.size,
+                name: file.name.clone(),
+                thumbnail: file.thumbnail.clone(),
+                r#type: file.r#type.clone(),
+            })
+        };
+
+        let server_message = match &msg.server_message {
+            None => None,
+            Some(msg) => {
+                let mut value = serde_json::Map::new();
+
+                match msg {
+                    ConversationServerMessageType::UserCreatedConversation(user) => {
+                        value.insert("type".to_string(), Value::from("user_created_conv"));
+                        value.insert("user_id".to_string(), Value::from(user.id()));
+                    }
+
+                    ConversationServerMessageType::UserAddedAnotherUserToConversation(msg) => {
+                        value.insert("type".to_string(), Value::from("user_added_another"));
+                        value.insert("user_who_added".to_string(), Value::from(msg.user_who_added.id()));
+                        value.insert("user_added".to_string(), Value::from(msg.user_added.id()));
+                    }
+
+                    ConversationServerMessageType::UserLeftConversation(u) => {
+                        value.insert("type".to_string(), Value::from("user_left"));
+                        value.insert("user_id".to_string(), Value::from(u.id()));
+                    }
+
+                    ConversationServerMessageType::UserRemovedFromConversation(msg) => {
+                        value.insert("type".to_string(), Value::from("user_removed_another"));
+                        value.insert("user_who_removed".to_string(), Value::from(msg.user_who_removed.id()));
+                        value.insert("user_removed".to_string(), Value::from(msg.user_removed.id()));
+                    }
+                }
+
+                Some(serde_json::Value::Object(value))
+            }
+        };
+
         ConversationMessageAPI {
-            ID: msg.id,
-            convID: msg.conv_id,
-            ID_user: msg.user_id.id(),
+            id: msg.id,
+            conv_id: msg.conv_id,
+            user_id: msg.user_id.clone().map(|u| u.id()),
             time_insert: msg.time_sent,
-            message: msg.message.clone().unwrap_or(String::new()),
-            image_path: msg.image_path.as_ref().map(|f| user_data_url(f)),
+            message: msg.message.clone(),
+            file,
+            server_message,
         }
     }
 
diff --git a/src/data/account_export.rs b/src/data/account_export.rs
index d19c0d1..5c9772a 100644
--- a/src/data/account_export.rs
+++ b/src/data/account_export.rs
@@ -61,7 +61,7 @@ impl AccountExport {
 
         // Conversation messages
         for (_, conv_messages) in &self.conversation_messages {
-            conv_messages.iter().for_each(|f| { set.insert(f.user_id.clone()); })
+            conv_messages.iter().for_each(|f| { set.extend(f.referenced_users_id()); })
         }
 
         Ok(set)
diff --git a/src/data/conversation_message.rs b/src/data/conversation_message.rs
index 5a6212b..b9183ea 100644
--- a/src/data/conversation_message.rs
+++ b/src/data/conversation_message.rs
@@ -2,15 +2,141 @@
 //!
 //! Information about a single conversation message
 
+use std::collections::HashSet;
+
+use crate::data::error::{ExecError, Res};
 use crate::data::user::UserID;
 
+pub type ConvMessageID = u64;
+
+#[derive(Debug)]
+pub struct ConversationMessageFile {
+    pub path: String,
+    pub size: u64,
+    pub name: String,
+    pub thumbnail: Option<String>,
+    pub r#type: String,
+}
+
+#[derive(Debug)]
+pub struct UserAddedAnotherUserToConversation {
+    pub user_who_added: UserID,
+    pub user_added: UserID,
+}
+
+#[derive(Debug)]
+pub struct UserRemovedAnotherUserToConversation {
+    pub user_who_removed: UserID,
+    pub user_removed: UserID,
+}
+
+#[derive(Debug)]
+pub enum ConversationServerMessageType {
+    UserCreatedConversation(UserID),
+    UserAddedAnotherUserToConversation(UserAddedAnotherUserToConversation),
+    UserLeftConversation(UserID),
+    UserRemovedFromConversation(UserRemovedAnotherUserToConversation),
+}
+
+impl ConversationServerMessageType {
+    pub fn to_db(&self) -> String {
+        let info = match self {
+            ConversationServerMessageType::UserCreatedConversation(u) => ("user_created_conv", Some(u.clone()), None),
+            ConversationServerMessageType::UserAddedAnotherUserToConversation(msg) => ("user_added_another_user", Some(msg.user_who_added.clone()), Some(msg.user_added.clone())),
+            ConversationServerMessageType::UserLeftConversation(u) => ("user_left", Some(u.clone()), None),
+            ConversationServerMessageType::UserRemovedFromConversation(msg) => ("user_removed", Some(msg.user_who_removed.clone()), Some(msg.user_removed.clone())),
+        };
+
+        format!(
+            "{}-{}-{}",
+            info.0,
+            info.1.map(|u| u.id()).unwrap_or(0),
+            info.2.map(|u| u.id()).unwrap_or(0)
+        )
+    }
+
+    pub fn from_db(str: &str) -> Res<Self> {
+        let split: Vec<&str> = str.split("-").collect();
+
+        if split.len() != 3 {
+            return Err(ExecError::boxed_new("Invalid ConversationSerMessageType"));
+        }
+
+        let id_1 = split[1].parse::<u64>()?;
+        let id_2 = split[2].parse::<u64>()?;
+        let info = (
+            split[0],
+            match id_1 {
+                0 => None,
+                id => Some(UserID::new(id))
+            },
+            match id_2 {
+                0 => None,
+                id => Some(UserID::new(id))
+            },
+        );
+
+        match info {
+            ("user_created_conv", Some(user_id), _) => Ok(Self::UserCreatedConversation(user_id)),
+
+            ("user_added_another_user", Some(user_id), Some(user_2)) => Ok(Self::UserAddedAnotherUserToConversation(UserAddedAnotherUserToConversation {
+                user_who_added: user_id,
+                user_added: user_2,
+            })),
+
+            ("user_left", Some(user_id), _) => Ok(Self::UserLeftConversation(user_id)),
+
+            ("user_removed", Some(user_id), Some(user_2)) => Ok(Self::UserRemovedFromConversation(UserRemovedAnotherUserToConversation {
+                user_who_removed: user_id,
+                user_removed: user_2,
+            })),
+
+            _ => Err(ExecError::boxed_new("Unknown server message type!"))
+        }
+    }
+}
+
 /// Information about a single conversation message
 #[derive(Debug)]
 pub struct ConversationMessage {
-    pub id: u64,
+    pub id: ConvMessageID,
     pub time_sent: u64,
     pub conv_id: u64,
-    pub user_id: UserID,
+    pub user_id: Option<UserID>,
     pub message: Option<String>,
-    pub image_path: Option<String>,
+    pub server_message: Option<ConversationServerMessageType>,
+    pub file: Option<ConversationMessageFile>,
+}
+
+impl ConversationMessage {
+    /// Get the entire list of referenced users in a conversation message
+    pub fn referenced_users_id(&self) -> HashSet<UserID> {
+        let mut users = HashSet::new();
+
+        if let Some(user_id) = &self.user_id {
+            users.insert(user_id.clone());
+        }
+
+        if let Some(srv_msg) = &self.server_message {
+            match srv_msg {
+                ConversationServerMessageType::UserCreatedConversation(user) => {
+                    users.insert(user.clone());
+                }
+                ConversationServerMessageType::UserAddedAnotherUserToConversation(msg) => {
+                    users.insert(msg.user_who_added.clone());
+                    users.insert(msg.user_added.clone());
+                }
+
+                ConversationServerMessageType::UserLeftConversation(user) => {
+                    users.insert(user.clone());
+                }
+                ConversationServerMessageType::UserRemovedFromConversation(msg) => {
+                    users.insert(msg.user_who_removed.clone());
+                    users.insert(msg.user_removed.clone());
+                }
+            }
+        }
+
+        users
+    }
 }
\ No newline at end of file
diff --git a/src/helpers/conversations_helper.rs b/src/helpers/conversations_helper.rs
index f61e606..b6c57fe 100644
--- a/src/helpers/conversations_helper.rs
+++ b/src/helpers/conversations_helper.rs
@@ -2,9 +2,9 @@
 //!
 //! @author Pierre Hubert
 
-use crate::constants::database_tables_names::{CONV_LIST_TABLE, CONV_MESSAGES_TABLE, CONV_MEMBERS_TABLE};
+use crate::constants::database_tables_names::{CONV_LIST_TABLE, CONV_MEMBERS_TABLE, CONV_MESSAGES_TABLE};
 use crate::data::conversation::Conversation;
-use crate::data::conversation_message::ConversationMessage;
+use crate::data::conversation_message::{ConversationMessage, ConversationMessageFile, ConversationServerMessageType};
 use crate::data::error::{ExecError, Res, ResultBoxError};
 use crate::data::new_conversation::NewConversation;
 use crate::data::new_conversation_message::NewConversationMessage;
@@ -14,7 +14,7 @@ use crate::helpers::{database, events_helper};
 use crate::helpers::database::InsertQuery;
 use crate::helpers::events_helper::Event;
 use crate::utils::date_utils::time;
-use crate::utils::user_data_utils::user_data_path;
+use crate::utils::user_data_utils::delete_user_data_file_if_exists;
 
 /// Create a new conversation. This method returns the ID of the created conversation
 pub fn create(conv: &NewConversation) -> ResultBoxError<u64> {
@@ -377,11 +377,12 @@ pub fn update_message_content(msg_id: u64, new_content: &str) -> ResultBoxError<
 /// Remove a message from a conversation
 pub fn delete_message(msg: &ConversationMessage) -> ResultBoxError<()> {
 
-    // Delete associated image (if any)
-    if let Some(img) = &msg.image_path {
-        let path = user_data_path(img.as_ref());
-        if path.exists() {
-            std::fs::remove_file(path)?;
+    // Delete associated files
+    if let Some(file) = &msg.file {
+        delete_user_data_file_if_exists(&file.path)?;
+
+        if let Some(thumb) = &file.thumbnail {
+            delete_user_data_file_if_exists(thumb)?;
         }
     }
 
@@ -523,12 +524,39 @@ fn db_to_conversation_info(row: &database::RowResult) -> ResultBoxError<Conversa
 
 /// Turn a database entry into a ConversationMessgae object
 fn db_to_conversation_message(row: &database::RowResult) -> ResultBoxError<ConversationMessage> {
+    let user_id = match row.is_null("user_id")? {
+        true => None,
+        false => Some(row.get_user_id("user_id")?)
+    };
+
+    let file = match row.is_null_or_empty("filepath")? {
+        true => None,
+        false => Some(ConversationMessageFile {
+            path: row.get_str("filepath")?,
+            size: row.get_u64("file_size")?,
+            name: row.get_str("file_name")?,
+            thumbnail: row.get_optional_str("file_thumbnail")?,
+            r#type: row.get_str("file_type")?,
+        })
+    };
+
+    let server_message = match &user_id {
+        Some(_) => None,
+        None => Some(ConversationServerMessageType::from_db(&row.get_str("message")?)?)
+    };
+
+    let message = match server_message {
+        None => row.get_optional_str("message")?,
+        Some(_) => None,
+    };
+
     Ok(ConversationMessage {
         id: row.get_u64("id")?,
-        time_sent: row.get_u64("time_insert")?,
+        time_sent: row.get_u64("time_sent")?,
         conv_id: row.get_u64("conv_id")?,
-        user_id: row.get_user_id("user_id")?,
-        message: row.get_optional_str("message")?,
-        image_path: row.get_optional_str("image_path")?,
+        user_id,
+        message,
+        server_message,
+        file,
     })
 }
\ No newline at end of file
diff --git a/src/helpers/database.rs b/src/helpers/database.rs
index 032cbae..b2e7a02 100644
--- a/src/helpers/database.rs
+++ b/src/helpers/database.rs
@@ -380,6 +380,15 @@ impl<'a> RowResult<'a> {
         }
     }
 
+    /// Check out whether a given value is null or empty or not
+    pub fn is_null_or_empty(&self, name: &str) -> ResultBoxError<bool> {
+        if self.is_null(name)? {
+            return Ok(true);
+        }
+
+        Ok(self.get_str(name)?.is_empty())
+    }
+
     /// Get an optional string => Set to None if string is null / empty
     pub fn get_optional_str(&self, name: &str) -> ResultBoxError<Option<String>> {
         match self.is_null(name)? {
diff --git a/src/main.rs b/src/main.rs
index aad276a..6cca797 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,7 @@
 use comunic_server::{cleanup_thread, server};
+use comunic_server::api_data::conversation_message_api::ConversationMessageAPI;
 use comunic_server::data::config::{conf, Config};
-use comunic_server::helpers::database;
+use comunic_server::helpers::{conversations_helper, database};
 
 #[actix_rt::main]
 async fn main() -> std::io::Result<()> {
@@ -18,6 +19,10 @@ async fn main() -> std::io::Result<()> {
     // Start cleanup thread
     cleanup_thread::start().expect("Failed to start cleanup thread!");
 
+    let msg = conversations_helper::get_last_messages(120, 100).unwrap();
+    println!("{:#?}", msg);
+    println!("{:#?}", serde_json::to_string(&ConversationMessageAPI::for_list(&msg)));
+
     // Start the server
     server::start_server(conf()).await
 }
diff --git a/src/utils/user_data_utils.rs b/src/utils/user_data_utils.rs
index edbb7cc..2e69501 100644
--- a/src/utils/user_data_utils.rs
+++ b/src/utils/user_data_utils.rs
@@ -7,7 +7,7 @@ use std::path::{Path, PathBuf};
 use serde_json::to_string;
 
 use crate::data::config::conf;
-use crate::data::error::{ExecError, ResultBoxError};
+use crate::data::error::{ExecError, Res, ResultBoxError};
 use crate::data::user::UserID;
 use crate::utils::crypt_utils::rand_str;
 
@@ -61,4 +61,13 @@ pub fn generate_new_user_data_file_name(dir: &Path, ext: &str) -> ResultBoxError
             return Ok(dir.join(&file));
         }
     }
+}
+
+/// Delete a file from user data, if it exists
+pub fn delete_user_data_file_if_exists(path: &str) -> Res {
+    let path = user_data_path(path.as_ref());
+    if path.exists() {
+        std::fs::remove_file(path)?;
+    }
+    Ok(())
 }
\ No newline at end of file