diff --git a/reid/examples/testcodegen.rs b/reid/examples/testcodegen.rs
index 8c6b2d2..a8adaaf 100644
--- a/reid/examples/testcodegen.rs
+++ b/reid/examples/testcodegen.rs
@@ -163,6 +163,7 @@ fn main() {
             name: "test module".to_owned(),
             imports: vec![],
             functions: vec![fibonacci, main],
+            typedefs: Vec::new(),
             path: None,
             is_main: true,
         }],
diff --git a/reid/src/ast/process.rs b/reid/src/ast/process.rs
index 39f8bd5..93e88d4 100644
--- a/reid/src/ast/process.rs
+++ b/reid/src/ast/process.rs
@@ -72,6 +72,7 @@ impl ast::Module {
             functions,
             path: self.path.clone(),
             is_main: self.is_main,
+            typedefs: todo!("process for typedefs"),
         }
     }
 }
@@ -197,7 +198,7 @@ impl ast::Expression {
             ast::ExpressionKind::Array(expressions) => {
                 mir::ExprKind::Array(expressions.iter().map(|e| e.process()).collect())
             }
-            ast::ExpressionKind::ArrayIndex(expression, idx) => mir::ExprKind::Index(
+            ast::ExpressionKind::ArrayIndex(expression, idx) => mir::ExprKind::ArrayIndex(
                 Box::new(expression.process()),
                 mir::TypeKind::Vague(mir::VagueType::Unknown),
                 *idx,
diff --git a/reid/src/codegen.rs b/reid/src/codegen.rs
index 1186736..465873a 100644
--- a/reid/src/codegen.rs
+++ b/reid/src/codegen.rs
@@ -385,7 +385,7 @@ impl mir::Expression {
                     None
                 }
             }
-            mir::ExprKind::Index(expression, val_t, idx) => {
+            mir::ExprKind::ArrayIndex(expression, val_t, idx) => {
                 let array = expression.codegen(scope)?;
                 let ptr = scope
                     .block
@@ -428,6 +428,10 @@ impl mir::Expression {
 
                 Some(array)
             }
+            mir::ExprKind::StructIndex(expression, type_kind, _) => {
+                todo!("codegen for struct index")
+            }
+            mir::ExprKind::Struct(_, items) => todo!("codegen for struct expression"),
         }
     }
 }
@@ -511,6 +515,7 @@ impl TypeKind {
             TypeKind::Array(elem_t, _) => Type::Ptr(Box::new(elem_t.get_type())),
             TypeKind::Void => Type::Void,
             TypeKind::Vague(_) => panic!("Tried to compile a vague type!"),
+            TypeKind::CustomType(_, custom_type_kind) => todo!("codegen for custom type"),
         }
     }
 }
diff --git a/reid/src/mir/display.rs b/reid/src/mir/display.rs
index 21e3645..e40e04b 100644
--- a/reid/src/mir/display.rs
+++ b/reid/src/mir/display.rs
@@ -130,7 +130,7 @@ impl Display for ExprKind {
             ExprKind::FunctionCall(fc) => Display::fmt(fc, f),
             ExprKind::If(if_exp) => Display::fmt(&if_exp, f),
             ExprKind::Block(block) => Display::fmt(block, f),
-            ExprKind::Index(expression, elem_ty, idx) => {
+            ExprKind::ArrayIndex(expression, elem_ty, idx) => {
                 Display::fmt(&expression, f)?;
                 write!(f, "<{}>", elem_ty)?;
                 write_index(f, *idx)
@@ -152,6 +152,28 @@ impl Display for ExprKind {
                 }
                 f.write_char(']')
             }
+            ExprKind::Struct(name, items) => {
+                write!(f, "{} ", name);
+
+                f.write_char('{')?;
+                let mut state = Default::default();
+                let mut inner_f = PadAdapter::wrap(f, &mut state);
+                let mut iter = items.iter();
+                if let Some((name, expr)) = iter.next() {
+                    write!(inner_f, "\n{}: {}", name, expr);
+                    while let Some((name, expr)) = iter.next() {
+                        writeln!(inner_f, ",")?;
+                        write!(inner_f, "{}: {}", name, expr);
+                    }
+                    writeln!(inner_f, "")?;
+                }
+                f.write_char('}')
+            }
+            ExprKind::StructIndex(expression, type_kind, name) => {
+                Display::fmt(&expression, f)?;
+                write!(f, "<{}>", type_kind)?;
+                write_access(f, name)
+            }
         }
     }
 }
@@ -254,3 +276,8 @@ fn write_index(f: &mut std::fmt::Formatter<'_>, idx: u64) -> std::fmt::Result {
     Display::fmt(&idx, f)?;
     f.write_char(']')
 }
+
+fn write_access(f: &mut std::fmt::Formatter<'_>, name: &String) -> std::fmt::Result {
+    f.write_char('.')?;
+    Display::fmt(name, f)
+}
diff --git a/reid/src/mir/mod.rs b/reid/src/mir/mod.rs
index f130ac3..a26f661 100644
--- a/reid/src/mir/mod.rs
+++ b/reid/src/mir/mod.rs
@@ -4,7 +4,7 @@
 
 use std::path::PathBuf;
 
-use crate::token_stream::TokenRange;
+use crate::{ast::Type, token_stream::TokenRange};
 
 mod display;
 pub mod linker;
@@ -65,6 +65,8 @@ pub enum TypeKind {
     StringPtr,
     #[error("[{0}; {1}]")]
     Array(Box<TypeKind>, u64),
+    #[error("{0} ({1})")]
+    CustomType(String, CustomTypeKind),
     #[error(transparent)]
     Vague(#[from] VagueType),
 }
@@ -79,6 +81,14 @@ pub enum VagueType {
     TypeRef(usize),
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, thiserror::Error)]
+pub enum CustomTypeKind {
+    #[error("struct({0:?})")]
+    Struct(Vec<TypeKind>),
+    #[error("CustomType")]
+    Unknown,
+}
+
 impl TypeKind {
     pub fn known(&self) -> Result<TypeKind, VagueType> {
         if let TypeKind::Vague(vague) = self {
@@ -107,6 +117,7 @@ impl TypeKind {
             TypeKind::U128 => false,
             TypeKind::StringPtr => false,
             TypeKind::Array(_, _) => false,
+            TypeKind::CustomType(_, _) => false,
         }
     }
 
@@ -126,8 +137,9 @@ impl TypeKind {
             Bool => true,
             Vague(_) => false,
             Void => false,
-            TypeKind::StringPtr => false,
+            StringPtr => false,
             Array(_, _) => false,
+            TypeKind::CustomType(_, _) => false,
         }
     }
 }
@@ -217,8 +229,10 @@ pub struct Import(pub Vec<String>, pub Metadata);
 #[derive(Debug)]
 pub enum ExprKind {
     Variable(NamedVariableRef),
-    Index(Box<Expression>, TypeKind, u64),
+    ArrayIndex(Box<Expression>, TypeKind, u64),
+    StructIndex(Box<Expression>, TypeKind, String),
     Array(Vec<Expression>),
+    Struct(String, Vec<(String, Expression)>),
     Literal(Literal),
     BinOp(BinaryOperator, Box<Expression>, Box<Expression>),
     FunctionCall(FunctionCall),
@@ -306,11 +320,23 @@ pub enum StmtKind {
     Expression(Expression),
 }
 
+#[derive(Debug)]
+pub struct TypeDefinition {
+    pub name: String,
+    pub kind: TypeDefinitionKind,
+}
+
+#[derive(Debug)]
+pub enum TypeDefinitionKind {
+    Struct(Vec<(String, Type)>),
+}
+
 #[derive(Debug)]
 pub struct Module {
     pub name: String,
     pub imports: Vec<Import>,
     pub functions: Vec<FunctionDefinition>,
+    pub typedefs: Vec<TypeDefinition>,
     pub path: Option<PathBuf>,
     pub is_main: bool,
 }
diff --git a/reid/src/mir/typecheck.rs b/reid/src/mir/typecheck.rs
index 2bf37b3..b6b0af7 100644
--- a/reid/src/mir/typecheck.rs
+++ b/reid/src/mir/typecheck.rs
@@ -427,7 +427,7 @@ impl Expression {
                 Ok((_, ty)) => Ok(ty),
                 Err(e) => Err(e),
             },
-            ExprKind::Index(expression, elem_ty, idx) => {
+            ExprKind::ArrayIndex(expression, elem_ty, idx) => {
                 // Try to unwrap hint type from array if possible
                 let hint_t = hint_t.map(|t| match t {
                     TypeKind::Array(type_kind, _) => &type_kind,
@@ -487,6 +487,10 @@ impl Expression {
                     }
                 }
             }
+            ExprKind::StructIndex(expression, type_kind, _) => {
+                todo!("typechecking for struct index")
+            }
+            ExprKind::Struct(_, items) => todo!("typechecking for struct expression"),
         }
     }
 }
diff --git a/reid/src/mir/typeinference.rs b/reid/src/mir/typeinference.rs
index 2e2b90f..861c284 100644
--- a/reid/src/mir/typeinference.rs
+++ b/reid/src/mir/typeinference.rs
@@ -283,7 +283,7 @@ impl Expression {
                     ReturnKind::Soft => Ok(block_ref.1),
                 }
             }
-            ExprKind::Index(expression, index_ty, _) => {
+            ExprKind::ArrayIndex(expression, index_ty, _) => {
                 let expr_ty = expression.infer_types(state, type_refs)?;
 
                 // Check that the resolved type is at least an array, no
@@ -336,6 +336,10 @@ impl Expression {
                     }
                 }
             }
+            ExprKind::StructIndex(expression, type_kind, _) => {
+                todo!("type inference for struct indexes")
+            }
+            ExprKind::Struct(_, items) => todo!("type inference for struct expression"),
         }
     }
 }
diff --git a/reid/src/mir/types.rs b/reid/src/mir/types.rs
index 0c66de5..094732d 100644
--- a/reid/src/mir/types.rs
+++ b/reid/src/mir/types.rs
@@ -1,3 +1,5 @@
+use crate::util::try_all;
+
 use super::*;
 
 #[derive(Debug, Clone)]
@@ -87,7 +89,7 @@ impl ReturnType for Expression {
             Block(block) => block.return_type(),
             FunctionCall(fcall) => fcall.return_type(),
             If(expr) => expr.return_type(),
-            Index(expression, _, _) => {
+            ArrayIndex(expression, _, _) => {
                 let expr_type = expression.return_type()?;
                 if let (_, TypeKind::Array(elem_ty, _)) = expr_type {
                     Ok((ReturnKind::Soft, *elem_ty))
@@ -106,6 +108,18 @@ impl ReturnType for Expression {
                     TypeKind::Array(Box::new(first.1), expressions.len() as u64),
                 ))
             }
+            StructIndex(expression, type_kind, _) => todo!("todo return type for struct index"),
+            Struct(name, items) => {
+                let f_types = try_all(items.iter().map(|e| e.1.return_type()).collect())
+                    .map_err(|e| unsafe { e.get_unchecked(0).clone() })?
+                    .iter()
+                    .map(|r| r.1.clone())
+                    .collect();
+                Ok((
+                    ReturnKind::Soft,
+                    TypeKind::CustomType(name.clone(), CustomTypeKind::Struct(f_types)),
+                ))
+            }
         }
     }
 }