diff --git a/src/data/api_client.rs b/src/data/api_client.rs
new file mode 100644
index 0000000..682b1ea
--- /dev/null
+++ b/src/data/api_client.rs
@@ -0,0 +1,11 @@
+/// API client information
+///
+/// @author Pierre HUBERT
+
+#[derive(Debug)]
+pub struct APIClient {
+    pub id: u32,
+    pub name: String,
+    pub token: String,
+    pub domain: Option<String>,
+}
\ No newline at end of file
diff --git a/src/data/http_request_handler.rs b/src/data/http_request_handler.rs
index 2564f62..1125819 100644
--- a/src/data/http_request_handler.rs
+++ b/src/data/http_request_handler.rs
@@ -5,6 +5,7 @@ use std::error::Error;
 use serde::Serialize;
 use crate::data::error::{ResultBoxError, ExecError};
 use std::collections::HashMap;
+use crate::helpers::api_helper;
 
 /// Http request handler
 ///
@@ -82,18 +83,23 @@ impl HttpRequestHandler {
         Err(Box::new(ExecError::new(&message)))
     }
 
+    /// If result is not OK, return a bad request
+    pub fn ok_or_bad_request<E>(&mut self, res: ResultBoxError<E>, msg: &str) -> ResultBoxError<E> {
+        match res {
+            Ok(e) => Ok(e),
+            Err(err) => {
+                println!("Error leading to bad request: {}", err);
+                self.bad_request(msg.to_string())?;
+                unreachable!()
+            },
+        }
+    }
+
     /// Get the path of the request
     pub fn request_path(&self) -> String {
         self.request.path().to_string()
     }
 
-    /// Check login tokens
-    pub fn check_client_token(&mut self) -> Result<(), Box<dyn Error>> {
-        println!("me = {}", self.post_string("me")?);
-
-        Ok(())
-    }
-
     /// Check if a POST parameter was present in the request or not
     pub fn has_post_parameter(&self, name: &str) -> bool {
         self.body.contains_key(name)
@@ -116,7 +122,22 @@ impl HttpRequestHandler {
             Some(s) => Ok(s.to_string()),
             None => {
                 Err(self.bad_request(format!("'{}' is not a string!", name)).unwrap_err())
-            },
+            }
         }
     }
+
+    /// Check login tokens
+    pub fn check_client_token(&mut self) -> Result<(), Box<dyn Error>> {
+        let api_name = self.post_string("serviceName")?;
+        let api_token = self.post_string("serviceToken")?;
+
+        let client = self.ok_or_bad_request(
+            api_helper::get_client(&api_name, &api_token),
+            "Client not recognized!"
+        )?;
+
+        // TODO  : continue here
+        println!("{:#?}", client);
+        Ok(())
+    }
 }
\ No newline at end of file
diff --git a/src/data/mod.rs b/src/data/mod.rs
index 4f8fcdb..d1c73c4 100644
--- a/src/data/mod.rs
+++ b/src/data/mod.rs
@@ -3,3 +3,4 @@ pub mod config;
 
 pub mod http_error;
 pub mod http_request_handler;
+pub mod api_client;
\ No newline at end of file
diff --git a/src/database_structure.rs b/src/database_structure.rs
new file mode 100644
index 0000000..7e2adc9
--- /dev/null
+++ b/src/database_structure.rs
@@ -0,0 +1,6 @@
+/// Database structure information
+///
+/// @author Pierre Hubert
+
+/// API services tokens table
+pub const SERVICES_TABLES : &str = "comunic_api_services_tokens";
\ No newline at end of file
diff --git a/src/helpers/api_helper.rs b/src/helpers/api_helper.rs
new file mode 100644
index 0000000..62f065c
--- /dev/null
+++ b/src/helpers/api_helper.rs
@@ -0,0 +1,27 @@
+use crate::data::api_client::APIClient;
+use crate::helpers::database;
+use crate::helpers::database::QueryInfo;
+use crate::database_structure::SERVICES_TABLES;
+use crate::data::error::ResultBoxError;
+
+/// API helper
+///
+/// @author Pierre Hubert
+
+/// Get information about a client
+pub fn get_client(name: &str, token: &str) -> ResultBoxError<APIClient> {
+    database::query_row(
+        QueryInfo::new(SERVICES_TABLES)
+            .cond("service_name", name)
+            .cond("token", token),
+
+            |res| {
+                Ok(APIClient {
+                    id: res.get_int64("id")? as u32,
+                    name: res.get_str("service_name")?,
+                    token: res.get_str("token")?,
+                    domain: res.get_optional_str("domain")?,
+                })
+            }
+    )
+}
\ No newline at end of file
diff --git a/src/helpers/database.rs b/src/helpers/database.rs
index 16e7ce5..6af9ef1 100644
--- a/src/helpers/database.rs
+++ b/src/helpers/database.rs
@@ -125,6 +125,14 @@ impl<'a> RowResult<'a> {
             Some(s) => Ok(s)
         }
     }
+
+    /// Get an optional string
+    pub fn get_optional_str(&self, name: &str) -> Result<Option<String>, ExecError> {
+        match self.find_col(name) {
+            Ok(col) => Ok(self.row.get(col)),
+            Err(_) => Ok(None),
+        }
+    }
 }
 
 
diff --git a/src/helpers/mod.rs b/src/helpers/mod.rs
index 3ea3f13..52decd0 100644
--- a/src/helpers/mod.rs
+++ b/src/helpers/mod.rs
@@ -1 +1,3 @@
-pub mod database;
\ No newline at end of file
+pub mod database;
+
+pub mod api_helper;
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 100a390..97a73fa 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
 pub mod data;
 pub mod helpers;
-pub mod controllers;
\ No newline at end of file
+pub mod controllers;
+pub mod database_structure;
\ No newline at end of file