diff --git a/crates/prometeu-compiler/src/common/diagnostics.rs b/crates/prometeu-compiler/src/common/diagnostics.rs
index e2515d8f..1dfed996 100644
--- a/crates/prometeu-compiler/src/common/diagnostics.rs
+++ b/crates/prometeu-compiler/src/common/diagnostics.rs
@@ -9,6 +9,7 @@ pub enum DiagnosticLevel {
 #[derive(Debug, Clone)]
 pub struct Diagnostic {
     pub level: DiagnosticLevel,
+    pub code: Option<String>,
     pub message: String,
     pub span: Option<Span>,
 }
@@ -33,6 +34,7 @@ impl DiagnosticBundle {
         let mut bundle = Self::new();
         bundle.push(Diagnostic {
             level: DiagnosticLevel::Error,
+            code: None,
             message,
             span,
         });
diff --git a/crates/prometeu-compiler/src/frontends/pbs/mod.rs b/crates/prometeu-compiler/src/frontends/pbs/mod.rs
index 41ec8a1b..8660092a 100644
--- a/crates/prometeu-compiler/src/frontends/pbs/mod.rs
+++ b/crates/prometeu-compiler/src/frontends/pbs/mod.rs
@@ -2,9 +2,15 @@ pub mod token;
 pub mod lexer;
 pub mod ast;
 pub mod parser;
+pub mod symbols;
+pub mod collector;
+pub mod resolver;
 
 pub use lexer::Lexer;
 pub use token::{Token, TokenKind};
+pub use symbols::{Symbol, SymbolTable, ModuleSymbols, Visibility, SymbolKind, Namespace};
+pub use collector::SymbolCollector;
+pub use resolver::{Resolver, ModuleProvider};
 
 use crate::common::diagnostics::DiagnosticBundle;
 use crate::common::files::FileManager;
@@ -30,9 +36,21 @@ impl Frontend for PbsFrontend {
         let file_id = file_manager.add(entry.to_path_buf(), source.clone());
 
         let mut parser = parser::Parser::new(&source, file_id);
-        let _ast = parser.parse_file()?;
+        let ast = parser.parse_file()?;
 
-        // Parsing and full compilation will be implemented in future PRs.
-        Err(DiagnosticBundle::error("Frontend 'pbs' not yet fully implemented (Parser OK)".to_string(), None))
+        let mut collector = SymbolCollector::new();
+        let (type_symbols, value_symbols) = collector.collect(&ast)?;
+        let module_symbols = ModuleSymbols { type_symbols, value_symbols };
+
+        struct EmptyProvider;
+        impl ModuleProvider for EmptyProvider {
+            fn get_module_symbols(&self, _path: &str) -> Option<&ModuleSymbols> { None }
+        }
+
+        let mut resolver = Resolver::new(&module_symbols, &EmptyProvider);
+        resolver.resolve(&ast)?;
+
+        // Compilation to IR will be implemented in future PRs.
+        Err(DiagnosticBundle::error("Frontend 'pbs' not yet fully implemented (Resolver OK)".to_string(), None))
     }
 }
diff --git a/crates/prometeu-compiler/src/frontends/pbs/parser.rs b/crates/prometeu-compiler/src/frontends/pbs/parser.rs
index 1798a459..e85615bc 100644
--- a/crates/prometeu-compiler/src/frontends/pbs/parser.rs
+++ b/crates/prometeu-compiler/src/frontends/pbs/parser.rs
@@ -630,6 +630,7 @@ impl Parser {
     fn error(&mut self, message: &str) -> DiagnosticBundle {
         let diag = Diagnostic {
             level: DiagnosticLevel::Error,
+            code: None,
             message: message.to_string(),
             span: Some(self.peek().span),
         };