diff --git a/compiler/cl-typeck/examples/typeck.rs b/compiler/cl-typeck/examples/typeck.rs
index 03f97c0..be3cd01 100644
--- a/compiler/cl-typeck/examples/typeck.rs
+++ b/compiler/cl-typeck/examples/typeck.rs
@@ -6,6 +6,7 @@ use cl_lexer::Lexer;
 use cl_parser::{inliner::ModuleInliner, Parser};
 use cl_typeck::{
     definition::Def,
+    handle::Handle,
     name_collector::NameCollector,
     node::{Node, NodeSource},
     project::Project,
@@ -118,8 +119,8 @@ fn query_type_expression(prj: &mut Project) -> Result<(), RlError> {
         }
         // parse it as a path, and convert the path into a borrowed path
         let ty = Parser::new(Lexer::new(line)).ty()?.kind;
-        let id = prj.evaluate(&ty, prj.root)?;
-        pretty_def(&prj[id], id);
+        let id = prj.evaluate(&ty, prj.root)?.handle_unchecked(prj);
+        pretty_handle(id)?;
         Ok(Response::Accept)
     })
 }
@@ -135,31 +136,43 @@ fn resolve_all(prj: &mut Project) -> Result<(), Box<dyn Error>> {
 
 fn list_types(prj: &mut Project) {
     println!("     name\x1b[30G  type");
-    for (idx, Def { kind, node: Node { vis, kind: source, .. }, .. }) in
-        prj.pool.values().enumerate()
-    {
-        print!("{idx:3}: {vis}");
-        if let Some(Some(name)) = source.as_ref().map(NodeSource::name) {
-            print!("{name}");
-        }
-        println!("\x1b[30G| {kind}")
+    for (idx, key) in prj.pool.keys().enumerate() {
+        let Def { node: Node { vis, kind: source, .. }, .. } = &prj[key];
+        let name = match source.as_ref().map(NodeSource::name) {
+            Some(Some(name)) => name,
+            _ => "".into(),
+        };
+        print!(
+            "{idx:3}: {vis}{name}\x1b[30G = {}",
+            key.handle_unchecked(prj)
+        );
+        println!();
     }
 }
 
-fn pretty_def(def: &Def, id: impl Into<usize>) {
-    let id = id.into();
-    let Def { module, kind, node: Node { meta, vis, kind: source, .. } } = def;
-    for meta in *meta {
-        println!("#[{meta}]")
+fn pretty_handle(handle: Handle) -> Result<(), std::io::Error> {
+    use std::io::Write;
+    let mut stdout = std::io::stdout().lock();
+    let Some(Def { module, node: Node { vis, .. }, .. }) = handle.get() else {
+        return writeln!(stdout, "Invalid handle: {handle}");
+    };
+    writeln!(stdout, "{C_LISTING}{vis}{handle}\x1b[0m: {}", handle.id())?;
+    if let Some(parent) = module.parent {
+        writeln!(stdout, "{C_LISTING}Parent\x1b[0m: {}", handle.with(parent))?;
     }
-    if let Some(Some(name)) = source.as_ref().map(NodeSource::name) {
-        print!("{vis}{name} ");
+    if !module.types.is_empty() {
+        writeln!(stdout, "{C_LISTING}Types:\x1b[0m")?;
+        for (name, def) in &module.types {
+            writeln!(stdout, "- {C_LISTING}{name}\x1b[0m: {}", handle.with(*def))?
+        }
     }
-    println!("[id: {id}] = {kind}");
-    if let Some(source) = source {
-        println!("Source:\n{C_LISTING}{source}\x1b[0m");
+    if !module.values.is_empty() {
+        writeln!(stdout, "{C_LISTING}Values:\x1b[0m")?;
+        for (name, def) in &module.values {
+            writeln!(stdout, "- {C_LISTING}{name}\x1b[0m: {}", handle.with(*def))?
+        }
     }
-    println!("\x1b[90m{module}\x1b[0m");
+    write!(stdout, "\x1b[0m")
 }
 
 fn inline_modules(code: cl_ast::File, path: impl AsRef<path::Path>) -> cl_ast::File {
diff --git a/compiler/cl-typeck/src/handle.rs b/compiler/cl-typeck/src/handle.rs
index 7cebd05..f0705d9 100644
--- a/compiler/cl-typeck/src/handle.rs
+++ b/compiler/cl-typeck/src/handle.rs
@@ -1,3 +1,4 @@
+use crate::{definition::Def, project::Project};
 use cl_structures::index_map::*;
 
 // define the index types
@@ -8,8 +9,170 @@ make_index! {
     DefID,
 }
 
-impl std::fmt::Display for DefID {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        self.0.fmt(f)
+/// A handle to a certain [Def] within a [Project]
+#[derive(Clone, Copy, Debug)]
+pub struct Handle<'prj, 'code> {
+    id: DefID,
+    prj: &'prj Project<'code>,
+}
+
+impl DefID {
+    /// Constructs a new [Handle] from this DefID and the provided [Project].
+    pub fn handle<'p, 'c>(self, prj: &'p Project<'c>) -> Option<Handle<'p, 'c>> {
+        Handle::new(self, prj)
+    }
+
+    /// Constructs a new [Handle] from this DefID and the provided [Project]
+    pub fn handle_unchecked<'p, 'c>(self, prj: &'p Project<'c>) -> Handle<'p, 'c> {
+        Handle::new_unchecked(self, prj)
+    }
+}
+
+impl<'p, 'c> Handle<'p, 'c> {
+    /// Constructs a new Handle from the provided [DefID] and [Project].
+    /// Returns [Some]\(Handle) if the [DefID] exists in the [Project].
+    pub fn new(id: DefID, prj: &'p Project<'c>) -> Option<Self> {
+        prj.pool.get(id).is_some().then_some(Self { id, prj })
+    }
+
+    /// Constructs a new Handle from the provided [DefID] and [Project] without checking membership.
+    /// Using the handle may cause panics or other unwanted (but defined) behavior.
+    pub fn new_unchecked(id: DefID, prj: &'p Project<'c>) -> Self {
+        Self { id, prj }
+    }
+
+    /// Gets the [Def] this handle points to.
+    pub fn get(self) -> Option<&'p Def<'c>> {
+        self.prj.pool.get(self.id)
+    }
+
+    /// Gets the [Project] this handle points to.
+    pub fn project(self) -> &'p Project<'c> {
+        self.prj
+    }
+
+    pub fn id(self) -> DefID {
+        self.id
+    }
+
+    // TODO: get parent, children, etc.
+
+    /// Gets a handle to the other ID within the same project
+    pub fn with(self, id: DefID) -> Self {
+        Self { id, ..self }
+    }
+}
+
+mod display {
+    use super::*;
+    use crate::{definition::*, format_utils::*};
+    use std::fmt::{self, Display, Write};
+
+    impl Display for DefID {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            self.0.fmt(f)
+        }
+    }
+
+    impl Display for Handle<'_, '_> {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            let Self { id, prj } = *self;
+            let Some(def) = prj.pool.get(id) else {
+                return write!(f, "<invalid type: {id}>");
+            };
+
+            // Match the type
+            match &def.kind {
+                DefKind::Undecided => write!(f, "<undecided>"),
+                DefKind::Impl(id) => write!(f, "impl {}", self.with(*id)),
+                DefKind::Use(id) => write!(f, "use inside {}", self.with(*id)),
+                DefKind::Type(kind) => match kind {
+                    TypeKind::Alias(None) => write!(f, "type"),
+                    TypeKind::Alias(Some(id)) => write!(f, "{}", self.with(*id)),
+                    TypeKind::Intrinsic(intrinsic) => write!(f, "{intrinsic}"),
+                    TypeKind::Adt(adt) => display_adt(self, adt, f),
+                    TypeKind::Ref(count, id) => {
+                        for _ in 0..*count {
+                            f.write_char('&')?;
+                        }
+                        self.with(*id).fmt(f)
+                    }
+                    TypeKind::Array(id, size) => {
+                        write!(f.delimit_with("[", "]"), "{}; {size}", self.with(*id))
+                    }
+                    TypeKind::Slice(id) => write!(f.delimit_with("[", "]"), "{}", self.with(*id)),
+                    TypeKind::Tuple(ids) => {
+                        let mut ids = ids.iter();
+                        separate(", ", || {
+                            let id = ids.next()?;
+                            Some(move |f: &mut Delimit<_>| write!(f, "{}", self.with(*id)))
+                        })(f.delimit_with("(", ")"))
+                    }
+                    TypeKind::FnSig { args, rety } => {
+                        write!(f, "fn {} -> {}", self.with(*args), self.with(*rety))
+                    }
+                    TypeKind::Empty => write!(f, "()"),
+                    TypeKind::Never => write!(f, "!"),
+                    TypeKind::Module => match def.name() {
+                        Some(name) => write!(f, "mod {name}"),
+                        None => write!(f, "mod"),
+                    },
+                },
+
+                DefKind::Value(kind) => match kind {
+                    ValueKind::Const(id) => write!(f, "const {}", self.with(*id)),
+                    ValueKind::Static(id) => write!(f, "static {}", self.with(*id)),
+                    ValueKind::Local(id) => write!(f, "local {}", self.with(*id)),
+                    ValueKind::Fn(id) => write!(f, "{}", self.with(*id)),
+                },
+            }
+        }
+    }
+
+    /// Formats an ADT: a continuation of [Handle::fmt]
+    fn display_adt(handle: &Handle, adt: &Adt, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match adt {
+            Adt::Enum(variants) => {
+                let mut variants = variants.iter();
+                separate(",", || {
+                    variants.next().map(|(name, def)| {
+                        move |f: &mut Delimit<_>| match def {
+                            Some(def) => write!(f, "\n{name}: {}", handle.with(*def)),
+                            None => write!(f, "\n{name}"),
+                        }
+                    })
+                })(f.delimit_with("enum {", "\n}"))
+            }
+            Adt::CLikeEnum(variants) => {
+                let mut variants = variants.iter();
+                separate(",", || {
+                    let (name, descrim) = variants.next()?;
+                    Some(move |f: &mut Delimit<_>| write!(f, "\n{name} = {descrim}"))
+                })(f.delimit_with("enum {", "\n}"))
+            }
+            Adt::FieldlessEnum => write!(f, "enum"),
+            Adt::Struct(members) => {
+                let mut members = members.iter();
+                separate(",", || {
+                    let (name, vis, id) = members.next()?;
+                    Some(move |f: &mut Delimit<_>| write!(f, "\n{vis}{name}: {}", handle.with(*id)))
+                })(f.delimit_with("struct {", "\n}"))
+            }
+            Adt::TupleStruct(members) => {
+                let mut members = members.iter();
+                separate(", ", || {
+                    let (vis, def) = members.next()?;
+                    Some(move |f: &mut Delimit<_>| write!(f, "{vis}{}", handle.with(*def)))
+                })(f.delimit_with("struct (", ")"))
+            }
+            Adt::UnitStruct => write!(f, "struct;"),
+            Adt::Union(variants) => {
+                let mut variants = variants.iter();
+                separate(",", || {
+                    let (name, def) = variants.next()?;
+                    Some(move |f: &mut Delimit<_>| write!(f, "\n{name}: {}", handle.with(*def)))
+                })(f.delimit_with("union {", "\n}"))
+            }
+        }
     }
 }