diff --git a/compiler/src/ast.rs b/compiler/src/ast.rs
index 16f20b3..e85272a 100644
--- a/compiler/src/ast.rs
+++ b/compiler/src/ast.rs
@@ -187,7 +187,7 @@ pub struct ArgDeclaration {
     pub ty: Option<ResolvedType>, 
 }
 
-#[derive(PartialEq,Debug)]
+#[derive(PartialEq,Debug, Clone)]
 pub struct Abi {
     pub loc : crate::Location,
     pub identifier : String,
diff --git a/compiler/src/inference.rs b/compiler/src/inference.rs
index 2eed7ea..90673ed 100644
--- a/compiler/src/inference.rs
+++ b/compiler/src/inference.rs
@@ -146,7 +146,7 @@ impl Context {
                     .map(|stmnt| self.assign_ids_stmnt(stmnt))
                     .collect(),
             ),
-            untyped_ast::ValueType::External => todo!(),
+            untyped_ast::ValueType::External => ast::ValueType::External,
         };
         ast::ValueDeclaration {
             loc,
@@ -156,6 +156,7 @@ impl Context {
             ty: decl_ty,
             value,
             generics: generictypes,
+            abi,
             id,
         }
     }
@@ -482,7 +483,8 @@ impl Context {
                         .reduce(|ty, arg| ty.fn_ty(&arg));
                     value.ty = fun.unwrap().fn_ty(&ty.unwrap()); //not sure if this the correct way to handle this.
                 }
-            }
+            },
+            ast::ValueType::External => (),
         }
     
     }
@@ -889,6 +891,7 @@ impl Context {
             ty: v_ty,
             value,
             generics,
+            abi:_,
             id: _,
         } = decl;
         v_ty.replace_unkown_with(id, ty.clone());
@@ -908,6 +911,7 @@ impl Context {
                     }
                 }
             }
+            ast::ValueType::External=>(),
         }
     }
 
@@ -938,6 +942,7 @@ impl Context {
                     self.apply_substution_statement(sub, stmnt);
                 }
             },
+            ast::ValueType::External=>()
         }
     }
 
@@ -1392,6 +1397,7 @@ mod tests {
                             2
                         )),
                         generics: None,
+                        abi:None,
                         id: 0
                     }
                 )]
@@ -1446,6 +1452,7 @@ mod tests {
                             }
                         )),
                         generics: None,
+                        abi:None,
                         id: 0
                     }
                 )]
@@ -1538,6 +1545,7 @@ let foo a = match a where
                             }
                         )),
                         generics: None,
+                        abi: None,
                         id: 0,
                     }
                 )]
@@ -1579,6 +1587,7 @@ let foo a = match a where
                             }
                         )),
                         generics: None,
+                        abi: None,
                         id: 0
                     }
                 )]
@@ -1653,6 +1662,7 @@ for<T> let foo x y : T -> T -> () = ()
                                 ((1,4),"T".to_string())
                             ] 
                         }),
+                        abi: None,
                         id: 0
                     }
                 )]
@@ -1756,6 +1766,7 @@ let complex x =
                             id: 2
                         }),
                         generics: None,
+                        abi: None,
                         id: 0
                     }),
                     super::ast::Declaration::Value(super::ast::ValueDeclaration {
@@ -1875,6 +1886,7 @@ let complex x =
                             )
                         ]),
                         generics: None,
+                        abi: None,
                         id: 7
                     }),
                     // super::ast::ValueDeclaration {
@@ -1954,6 +1966,7 @@ let unit_unit _ : () -> () = ()
                 },
                 value: super::ast::ValueType::Expr(super::ast::Expr::ValueRead("x".to_string(), (5,33), 7)),
                 generics: None,
+                abi: None,
                 id: 5
             }),
             int_int,
@@ -1979,6 +1992,7 @@ let unit_unit _ : () -> () = ()
                 },
                 value: super::ast::ValueType::Expr(super::ast::Expr::UnitLiteral),
                 generics: None,
+                abi: None,
                 id: 0
             }),
             int_unit,
@@ -2004,6 +2018,7 @@ let unit_unit _ : () -> () = ()
                 },
                 value: super::ast::ValueType::Expr(super::ast::Expr::NumericLiteral { value: "0".to_string(), id: 4, ty: types::INT16 }),
                 generics: None,
+                abi: None,
                 id: 2
             }),
             unit_int,
@@ -2029,6 +2044,7 @@ let unit_unit _ : () -> () = ()
                 },
                 value: super::ast::ValueType::Expr(super::ast::Expr::UnitLiteral),
                 generics: None,
+                abi: None,
                 id: 8
             }),
             unit_unit,
@@ -2081,7 +2097,6 @@ let if_expr a b : bool -> int32 -> int32 = if a then b else 0
                     }.boxed(),
                     loc:(1, 23)
                 },
-                id:0,
                 value: super::ast::ValueType::Expr(super::ast::Expr::If(super::ast::IfExpr {
                     cond: super::ast::Expr::ValueRead("a".to_string(), (1,46), 4).boxed(),
                     true_branch: (
@@ -2097,7 +2112,9 @@ let if_expr a b : bool -> int32 -> int32 = if a then b else 0
                     id: 3,
                     result: types::INT32 
                 })),
-                generics:None
+                generics:None,
+                abi: None,
+                id:0,
             }),
             if_expr,
         )
@@ -2141,7 +2158,6 @@ let returns a : bool -> int32 =
                     returns: types::INT32.boxed(),
                     loc: (1,21) 
                 },
-                generics:None,
                 value:super::ast::ValueType::Function(vec![
                     super::ast::Statement::IfStatement(super::ast::IfBranching{
                         cond: super::ast::Expr::ValueRead("a".to_string(), (2,7), 2).boxed(),
@@ -2160,6 +2176,8 @@ let returns a : bool -> int32 =
                         (4,4)
                     )
                 ]),
+                generics:None,
+                abi: None,
                 id:0
             }),
             returns,
diff --git a/compiler/src/inference/ast.rs b/compiler/src/inference/ast.rs
index 69f19cd..81714ca 100644
--- a/compiler/src/inference/ast.rs
+++ b/compiler/src/inference/ast.rs
@@ -46,6 +46,7 @@ pub(crate) struct ValueDeclaration {
     pub(crate) ty: ResolvedType,
     pub(crate) value: ValueType,
     pub(crate) generics: Option<GenericsDecl>,
+    pub(crate) abi : Option<crate::ast::Abi>,
     pub(crate) id: usize,
 }
 
@@ -61,6 +62,7 @@ pub struct ArgDeclaration {
 pub(crate) enum ValueType {
     Expr(Expr),
     Function(Vec<Statement>),
+    External,
 }
 
 #[derive(PartialEq, Debug)]
diff --git a/compiler/src/typed_ast.rs b/compiler/src/typed_ast.rs
index 79d4177..794a026 100644
--- a/compiler/src/typed_ast.rs
+++ b/compiler/src/typed_ast.rs
@@ -370,6 +370,7 @@ pub struct TypedValueDeclaration {
     pub value: TypedValueType,
     pub ty: ResolvedType,
     pub generictypes: Option<ResolvedGenericsDecl>,
+    pub abi : Option<crate::ast::Abi>,
     pub is_curried: bool,
 }
 pub fn collect_args(t: &ResolvedType) -> Vec<ResolvedType> {
@@ -395,6 +396,7 @@ impl TypedValueDeclaration {
             TypedValueType::Function(stmnts) => stmnts
                 .into_iter()
                 .for_each(|expr| expr.replace_types(&replaced)),
+            TypedValueType::External |
             TypedValueType::Err => (),
         }
     }
@@ -412,6 +414,7 @@ impl TypedValueDeclaration {
             ty,
             value,
             generics,
+            abi,
             id: _,
         } = data;
         let mut known_values = known_values.clone();
@@ -441,6 +444,7 @@ impl TypedValueDeclaration {
             ty: if is_curried { value.get_ty() } else { ty },
             value,
             generictypes : generics.map(ResolvedGenericsDecl::from),
+            abi,
         })
     }
     fn lower_generics(&mut self, context: &mut LoweringContext) {
@@ -454,6 +458,7 @@ impl TypedValueDeclaration {
                 }
             }
             TypedValueType::Err => todo!(),
+            TypedValueType::External => (),
         }
     }
 }
@@ -463,6 +468,7 @@ pub enum TypedValueType {
     Expr(TypedExpr),
     Function(Vec<TypedStatement>),
     Err,
+    External,
 }
 
 impl TypedValueType {
@@ -518,7 +524,8 @@ impl TypedValueType {
                 } else {
                     Ok(TypedValueType::Function(output))
                 }
-            }
+            },
+            ast::ValueType::External => Ok(TypedValueType::External),
         }
     }
 
@@ -543,7 +550,8 @@ impl TypedValueType {
                         }
                     },
                 ),
-            Self::Err => todo!(),
+            Self::Err => types::ERROR,
+            Self::External => types::ERROR
         }
     }
 }
@@ -620,6 +628,7 @@ impl TypedStatement {
                 TypedValueType::Function(_) => {
                     todo!("how to handle this one :/ function inside function");
                 }
+                TypedValueType::External |
                 TypedValueType::Err => (),
             },
             Self::Discard(expr, _) | Self::Return(expr, _) => expr.lower_generics(context),
@@ -1788,6 +1797,7 @@ fn modify_declaration(
                     stmnt.lower_generics(context);
                 }
             }
+            TypedValueType::External |
             TypedValueType::Err => (),
         }
         to_lower
@@ -2868,6 +2878,7 @@ let main _ : () -> () =
                         id: 1
                     }),
                     generics: None,
+                    abi: None,
                     id:0
                 }),
                 &HashMap::new(),
@@ -2885,6 +2896,7 @@ let main _ : () -> () =
                 }),
                 ty: types::INT32,
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             "decl statement"
@@ -2970,6 +2982,7 @@ let main _ : () -> () =
                         (0, 0)
                     )]),
                     generics: None,
+                    abi: None,
                     id:0
                 }),
                 &HashMap::new(),
@@ -3000,6 +3013,7 @@ let main _ : () -> () =
                     (0, 0)
                 )]),
                 generictypes: None,
+                abi: None,
                 is_curried: false
             }),
             r#"let test a : int32 -> int32 = 
@@ -3096,6 +3110,7 @@ let main _ : () -> () =
                     ],
                 }),
                 is_curried: false,
+                abi: None,
             }),
             generic,
             "generic"
@@ -3120,6 +3135,7 @@ let main _ : () -> () =
                     value: TypedValueType::Expr(TypedExpr::IntegerLiteral { value: "3".to_string(), size: types::IntWidth::ThirtyTwo }),
                     ty: types::INT32,
                     generictypes: None,
+                    abi: None,
                     is_curried: false,
                 }),
                 TypedStatement::FnCall(TypedFnCall {
@@ -3155,6 +3171,7 @@ let main _ : () -> () =
                     loc:(0,0)
                 },
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             main,
@@ -3285,6 +3302,7 @@ let first a : Tuple<int32,float64> -> int32 =
                     loc:(7,36)
                 },
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             "post lowering function"
@@ -3402,6 +3420,7 @@ let main x : int32 -> int32 =
                     ],
                 }),
                 is_curried: false,
+                abi: None,
             }),
             generic,
             "generic should be untouched"
@@ -3451,6 +3470,7 @@ let main x : int32 -> int32 =
                 },
                 generictypes: None,
                 is_curried: false,
+                abi: None,
             }),
             main,
             "main should have the value read changed"
@@ -3476,6 +3496,7 @@ let main x : int32 -> int32 =
                     loc:(0,0)
                 },
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             generated,
@@ -3608,6 +3629,7 @@ let statement_with_else_if a b : bool -> bool -> int32 =
                     loc:(0,0)
                 },
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             expr,
@@ -3673,6 +3695,7 @@ let statement_with_else_if a b : bool -> bool -> int32 =
                     }
                 )]),
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             stmnt,
@@ -3855,6 +3878,7 @@ let as_statement a b : int32 -> int32 -> () =
                     loc:(0,0)
                 },
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             simple,
@@ -3975,6 +3999,7 @@ let as_statement a b : int32 -> int32 -> () =
                     loc:(0,0)
                 },
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             nest_in_call,
@@ -4112,6 +4137,7 @@ let as_statement a b : int32 -> int32 -> () =
                     loc:(0,0)
                 },
                 generictypes: None,
+                abi: None,
                 is_curried: false,
             }),
             statement,
diff --git a/llvm-codegen/src/code_gen.rs b/llvm-codegen/src/code_gen.rs
index d72feec..3fbc7ea 100644
--- a/llvm-codegen/src/code_gen.rs
+++ b/llvm-codegen/src/code_gen.rs
@@ -358,6 +358,7 @@ impl<'ctx> CodeGen<'ctx> {
                 }
             }
             TypedValueType::Err => unreachable!("how did an error kind get here"),
+            TypedValueType::External => unreachable!("The external linkage should not be compiled")
         }
         self.difunction = None;
         self.dilocals.clear();
@@ -1764,9 +1765,28 @@ impl<'ctx> CodeGen<'ctx> {
     pub(crate) fn create_define(&mut self, decl: &TypedDeclaration) {
         match decl {
             TypedDeclaration::Value(decl) => {
-                if decl.ty.is_function() {
+                if let Some(abi) = &decl.abi {
+                    match abi.identifier.as_str() {
+                        "C" => {
+                            let (args,ret) = decl.ty.as_c_function();
+                            let ret = self.type_resolver.resolve_type_as_basic(ret);
+                            let args = args.into_iter().map(|it| self.type_resolver.resolve_type_as_basic(it).into()).collect_vec();
+                            let fun = self.module.add_function(&decl.ident, ret.fn_type(&args, false), Some(inkwell::module::Linkage::External));
+                            
+                            self.known_functions.insert(decl.ident.clone(), fun.as_global_value());
+                        },
+                        "intrinsic" => {
+                            ()// do nothing here as this is handled in the code gen itself.  eg `let (+) : int32 -> int32 -> int32` which should output an add signed instruction
+                        }
+                        _ => {
+                            println!("unknown abi {}", abi.identifier)
+                        }
+                    }
+                } else if decl.ty.is_function() {
                     let fun = self.create_curry_list(decl);
                     self.known_functions.insert(decl.ident.clone(), fun);
+                } else {
+                    //TODO! global values.
                 }
             }
             TypedDeclaration::TypeDefinition(def) => match def {
@@ -1973,7 +1993,10 @@ impl<'ctx> CodeGen<'ctx> {
         }
         #[cfg(debug_assertions)]
         let _ = self.module.print_to_file("./debug.llvm");
-        for decl in ast.declarations {
+        for decl in ast.declarations.into_iter().filter(|it| match it {
+            TypedDeclaration::Value(TypedValueDeclaration { value, .. }) if value == &TypedValueType::External => false,
+            _ => true,
+        }) {
             self.compile_decl(decl);
         }
         let mut prev_len = self.needsdi.len();