diff --git a/server/src/steel/handlers.rs b/server/src/steel/handlers.rs
deleted file mode 100644
index 2e1c6a4..0000000
--- a/server/src/steel/handlers.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-// src/steel/handlers.rs
-pub mod execution;
-
-pub use execution::*;
diff --git a/server/src/steel/mod.rs b/server/src/steel/mod.rs
index 181dd66..5759769 100644
--- a/server/src/steel/mod.rs
+++ b/server/src/steel/mod.rs
@@ -1,4 +1,3 @@
 // src/steel/mod.rs
 
-pub mod handlers;
-pub mod validation;
+pub mod server;
diff --git a/server/src/steel/server/data_access.rs b/server/src/steel/server/data_access.rs
new file mode 100644
index 0000000..0c68458
--- /dev/null
+++ b/server/src/steel/server/data_access.rs
@@ -0,0 +1,92 @@
+// src/steel/server/data_access.rs
+use crate::steel::server::{
+    rvals::{Custom, SteelVal},
+    SteelError,
+};
+use sqlx::{PgPool, Row};
+use std::collections::HashMap;
+
+pub struct TableAccess {
+    db_pool: PgPool,
+    profile_id: i64,
+    current_table: String,
+    local_data: HashMap<String, String>,
+}
+
+impl Custom for TableAccess {}
+
+impl TableAccess {
+    pub fn new(
+        db_pool: PgPool,
+        profile_id: i64,
+        current_table: &str,
+        local_data: HashMap<String, String>,
+    ) -> Self {
+        Self {
+            db_pool,
+            profile_id,
+            current_table: current_table.to_string(),
+            local_data,
+        }
+    }
+
+    async fn validate_link(&self, table: &str) -> Result<(), SteelError> {
+        let is_linked: bool = sqlx::query_scalar!(
+            r#"SELECT EXISTS(
+                SELECT 1 FROM table_definition_links tdl
+                JOIN table_definitions src ON tdl.source_table_id = src.id
+                JOIN table_definitions dst ON tdl.linked_table_id = dst.id
+                WHERE src.table_name = $1 AND dst.table_name = $2 AND src.profile_id = $3
+            )"#,
+            self.current_table,
+            table,
+            self.profile_id
+        )
+        .fetch_one(&self.db_pool)
+        .await
+        .map_err(|e| SteelError::new(e.to_string()))?
+        .unwrap_or(false);
+
+        if !is_linked {
+            return Err(SteelError::new(format!(
+                "Table '{}' is not linked to '{}'", 
+                table, self.current_table
+            )));
+        }
+
+        Ok(())
+    }
+
+    async fn get_external_value(&self, table: &str, column: &str) -> Result<SteelVal, SteelError> {
+        self.validate_link(table).await?;
+
+        let firma = self.local_data.get("firma")
+            .ok_or_else(|| SteelError::new("Missing 'firma' in local data"))?;
+
+        let query = format!(
+            "SELECT {} FROM \"{}\" WHERE firma = $1 AND profile_id = $2",
+            column, table
+        );
+
+        let value: Option<String> = sqlx::query(&query)
+            .bind(firma)
+            .bind(self.profile_id)
+            .fetch_optional(&self.db_pool)
+            .await
+            .map_err(|e| SteelError::new(e.to_string()))?
+            .and_then(|row| row.try_get(0).ok());
+
+        value
+            .map(SteelVal::StringV)
+            .ok_or_else(|| SteelError::new(format!("No value found for {}.{}", table, column)))
+    }
+}
+
+fn table_access_module(
+    db_pool: PgPool,
+    profile_id: i64,
+    current_table: String,
+    local_data: HashMap<String, String>,
+) -> Result<impl Custom, SteelError> {
+    Ok(TableAccess::new(db_pool, profile_id, &current_table, local_data))
+}
diff --git a/server/src/steel/handlers/execution.rs b/server/src/steel/server/execution.rs
similarity index 64%
rename from server/src/steel/handlers/execution.rs
rename to server/src/steel/server/execution.rs
index c8418ab..ac77583 100644
--- a/server/src/steel/handlers/execution.rs
+++ b/server/src/steel/server/execution.rs
@@ -1,4 +1,4 @@
-// src/steel/handlers/execution.rs
+// src/steel/server/execution.rs
 use std::fmt;
 use std::collections::HashMap;
 use sqlx::{PgPool, Row};
@@ -99,16 +99,21 @@ pub async fn resolve_value(
         let external_table = table.strip_prefix('@')
             .ok_or_else(|| ScriptExecutionError::InvalidReference(format!("Invalid external reference: {}", source)))?;
 
-        // Get linking key (assuming firma is the common key)
-        let firma = current_data.get("firma")
-            .ok_or_else(|| ScriptExecutionError::MissingLinkKey("firma".into()))?;
+        // Get foreign key relationship info
+        let (fk_column, referenced_column) = get_relationship_info(db_pool, current_table, external_table).await?;
 
-        // Query external table
-        let query = format!("SELECT {} FROM \"{}\" WHERE firma = $1 AND profile_id = $2", column, external_table);
+        // Get foreign key value from current data
+        let fk_value = current_data.get(&fk_column)
+            .ok_or_else(|| ScriptExecutionError::MissingLinkKey(fk_column.clone()))?;
+
+        // Build and execute query
+        let query = format!(
+            "SELECT {} FROM \"{}\" WHERE {} = $1",
+            column, external_table, referenced_column
+        );
 
         let result: Option<String> = sqlx::query(&query)
-            .bind(firma)
-            .bind(profile_id)
+            .bind(fk_value)
             .fetch_optional(db_pool)
             .await
             .map_err(|e| ScriptExecutionError::DatabaseError(e.to_string()))?
@@ -118,9 +123,58 @@ pub async fn resolve_value(
             format!("No data found for {} in {}", column, external_table)
         ))
     } else {
-        // Local column reference
+        // Local column reference remains the same
         current_data.get(source)
             .cloned()
             .ok_or_else(|| ScriptExecutionError::MissingSourceColumn(source.into()))
     }
 }
+
+async fn get_relationship_info(
+    db_pool: &PgPool,
+    current_table: &str,
+    external_table: &str,
+) -> Result<(String, String), ScriptExecutionError> {
+    let query = r#"
+        SELECT
+            kcu.column_name AS fk_column,
+            ccu.column_name AS referenced_column
+        FROM
+            information_schema.table_constraints AS tc
+            JOIN information_schema.key_column_usage AS kcu
+              ON tc.constraint_name = kcu.constraint_name
+              AND tc.table_schema = kcu.table_schema
+            JOIN information_schema.constraint_column_usage AS ccu
+              ON tc.constraint_name = ccu.constraint_name
+              AND tc.table_schema = ccu.table_schema
+        WHERE
+            tc.constraint_type = 'FOREIGN KEY'
+            AND tc.table_name = $1
+            AND ccu.table_name = $2
+    "#;
+
+    let rows = sqlx::query(query)
+        .bind(current_table)
+        .bind(external_table)
+        .fetch_all(db_pool)
+        .await
+        .map_err(|e| ScriptExecutionError::DatabaseError(e.to_string()))?;
+
+    match rows.len() {
+        0 => Err(ScriptExecutionError::InvalidReference(format!(
+            "No foreign key relationship found from {} to {}",
+            current_table, external_table
+        ))),
+        1 => {
+            let row = &rows[0];
+            Ok((
+                row.get::<String, _>("fk_column"),
+                row.get::<String, _>("referenced_column"),
+            ))
+        },
+        _ => Err(ScriptExecutionError::InvalidReference(format!(
+            "Multiple foreign keys between {} and {} - cannot resolve ambiguity",
+            current_table, external_table
+        )))
+    }
+}
diff --git a/server/src/steel/server/mod.rs b/server/src/steel/server/mod.rs
new file mode 100644
index 0000000..366096d
--- /dev/null
+++ b/server/src/steel/server/mod.rs
@@ -0,0 +1,10 @@
+// src/steel/server/mod.rs
+pub mod rvals;
+pub mod data_access;
+pub mod execution;
+pub mod script;
+
+pub use data_access::*;
+pub use execution::*;
+pub use script::*;
+pub use rvals::*;
diff --git a/server/src/steel/server/rvals.rs b/server/src/steel/server/rvals.rs
new file mode 100644
index 0000000..8de96a1
--- /dev/null
+++ b/server/src/steel/server/rvals.rs
@@ -0,0 +1,25 @@
+// src/steel/server/rvals.rs
+use std::fmt;
+
+#[derive(Debug)]
+pub struct SteelError {
+    pub message: String,
+}
+
+impl SteelError {
+    pub fn new(message: impl Into<String>) -> Self {
+        Self { message: message.into() }
+    }
+}
+
+impl fmt::Display for SteelError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+pub trait Custom {}
+pub enum SteelVal {
+    StringV(String),
+    // Add other variants as needed
+}
diff --git a/server/src/steel/validation/script.rs b/server/src/steel/server/script.rs
similarity index 95%
rename from server/src/steel/validation/script.rs
rename to server/src/steel/server/script.rs
index cd834f6..10b69db 100644
--- a/server/src/steel/validation/script.rs
+++ b/server/src/steel/server/script.rs
@@ -1,4 +1,4 @@
-// src/steel/validation/script.rs
+// src/steel/server/script.rs
 use std::fmt;
 
 #[derive(Debug)]
diff --git a/server/src/steel/validation.rs b/server/src/steel/validation.rs
deleted file mode 100644
index dd7047a..0000000
--- a/server/src/steel/validation.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-// src/steel/validation.rs
-pub mod script;
diff --git a/server/src/table_script/handlers/post_table_script.rs b/server/src/table_script/handlers/post_table_script.rs
index 4663fcb..580704f 100644
--- a/server/src/table_script/handlers/post_table_script.rs
+++ b/server/src/table_script/handlers/post_table_script.rs
@@ -2,11 +2,11 @@
 use tonic::Status;
 use sqlx::{PgPool, Error as SqlxError};
 use common::proto::multieko2::table_script::{PostTableScriptRequest, TableScriptResponse};
-use crate::steel::validation::script::validate_script;
+use crate::steel::server::script::validate_script;
 use serde_json::Value;
 
 // Add these imports for the execution module and ScriptOperation
-use crate::steel::handlers::execution::{self, ScriptOperation};
+use crate::steel::server::execution::{self, ScriptOperation};
 
 const SYSTEM_COLUMNS: &[&str] = &["id", "deleted", "created_at"];
 
diff --git a/server/src/tables_data/handlers/post_table_data.rs b/server/src/tables_data/handlers/post_table_data.rs
index 85a0479..fd3202b 100644
--- a/server/src/tables_data/handlers/post_table_data.rs
+++ b/server/src/tables_data/handlers/post_table_data.rs
@@ -4,7 +4,7 @@ use sqlx::{PgPool, Arguments};
 use sqlx::postgres::PgArguments;
 use chrono::{DateTime, Utc};
 use common::proto::multieko2::tables_data::{PostTableDataRequest, PostTableDataResponse};
-use crate::steel::handlers::execution::{self, ScriptOperation};
+use crate::steel::server::execution::{self, ScriptOperation};
 use std::collections::HashMap;
 
 pub async fn post_table_data(