diff --git a/bok-macro/src/lib.rs b/bok-macro/src/lib.rs
index 3e9bd00..34f2855 100644
--- a/bok-macro/src/lib.rs
+++ b/bok-macro/src/lib.rs
@@ -218,6 +218,31 @@ pub fn impl_package(_attrs: TokenStream, input: TokenStream) -> TokenStream {
             Some(&mut self.base)
         }
     };
+    let hash: ::syn::ImplItem = ::syn::parse_quote! {
+        fn hash(&self) -> ::bok::Hash {
+            use ::sha3::{Digest};
+            let mut hasher = ::sha3::Sha3_256::new();
+            let mut pkg_vars = String::new();
+            use ::std::fmt::Write;
+            write!(&mut pkg_vars,
+                "{:?}",
+                self,
+            );
+            hasher.update(&pkg_vars);
+            hasher.update(self.to_string());
+            let hash = hasher.finalize();
+            ::bok::Hash::Sha3(hash)
+        }
+    };
+    let hash_code: ::syn::ImplItem = ::syn::parse_quote! {
+        fn hash_code(&self) -> ::bok::Hash {
+            use ::sha3::{Digest};
+            let mut hasher = ::sha3::Sha3_256::new();
+            hasher.update(self.to_string());
+            let hash = hasher.finalize();
+            ::bok::Hash::Sha3(hash)
+        }
+    };
 
     for mut impl_item in ast.items.iter_mut() {
         if let ::syn::ImplItem::Fn(ref mut fn_impl) = &mut impl_item {
@@ -233,6 +258,8 @@ pub fn impl_package(_attrs: TokenStream, input: TokenStream) -> TokenStream {
 
     ast.items.push(base);
     ast.items.push(base_mut);
+    ast.items.push(hash);
+    ast.items.push(hash_code);
 
     quote! {
         #ast
@@ -432,6 +459,13 @@ pub fn derive_package(input: TokenStream) -> TokenStream {
 
     let expanded = quote! {
         impl ::core::fmt::Display for #name {
+            fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>)
+                ->::core::fmt::Result
+            {
+                <#name as ::bok::PkgCode>::fmt(self, f)
+            }
+        }
+        impl ::bok::PkgCode for #name {
             fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>)
                 ->::core::fmt::Result
             {
@@ -506,13 +540,6 @@ pub fn derive_package(input: TokenStream) -> TokenStream {
             pub fn builder() -> #name_builder {
                 #name_builder::default()
             }
-            pub fn hash() -> ::bok::Hash {
-                // FIXME: this does not capture the package field status
-                use ::sha3::{Digest, Sha3_256};
-                let mut hasher = ::sha3::Sha3_256::new();
-                let hash = hasher.finalize();
-                ::bok::Hash::Sha3(hash)
-            }
             #(pub fn #all_fields2(&self) -> &#all_types {
                 &self.#all_fields2
             })*
@@ -535,11 +562,13 @@ pub fn derive_package(input: TokenStream) -> TokenStream {
         */
         impl ::bok::PkgBuilder for #name_builder2 {
             type Package = #name;
-            fn default_unused(&mut self){
+            fn default_unused(&mut self) -> &mut dyn ::bok::PkgBuilder<Package = #name> {
                 let def = #name::default();
                 #(if self.#non_opt_fields5.is_none() {
                     self.#non_opt_fields5 = Some(def.#non_opt_fields5);
                 })*
+
+                self
             }
             fn build(&mut self) -> Result<#name, ::std::boxed::Box<dyn ::std::error::Error>> {
                 #(if self.#non_opt_fields2.is_none() {
diff --git a/bok-utils/src/main.rs b/bok-utils/src/main.rs
index eb9bf7d..51ca99e 100644
--- a/bok-utils/src/main.rs
+++ b/bok-utils/src/main.rs
@@ -45,7 +45,15 @@ fn main() {
     let b = pb.as_builder();
     let a = pb.as_any_mut();
     let m_pb2: Option<&mut pkgs::one::OneBuilder> = a.downcast_mut();
+    use ::bok::{Pkg, PkgBuilder};
     println!("m_pb2: {:?}", m_pb2);
+    let m_pkg = pb.default_unused().build();
+    println!("m_pb2: {:?}", m_pkg);
+    if let Ok(pkg) = m_pkg {
+        println!("one: {:?}", pkg);
+        println!("hash one: {}", pkg.hash());
+        println!("hash one code: {}", pkg.hash_code());
+    }
 
     println!("pkgs1 - 1:{}", pkgs1.one().my_attr);
     println!("pkgs1 - 2:{}", pkgs1.two().my_attr);
diff --git a/bok/src/lib.rs b/bok/src/lib.rs
index 215966e..8248a86 100644
--- a/bok/src/lib.rs
+++ b/bok/src/lib.rs
@@ -87,9 +87,13 @@ pub trait Repository: Default {}
 pub struct RepositoryEmpty {}
 impl Repository for RepositoryEmpty {}
 
+/// Print the code of the package
+pub trait PkgCode {
+    fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result;
+}
 /// Implement common package operations
 pub trait Pkg:
-    ::core::fmt::Debug + ::core::fmt::Display + ::std::any::Any
+    ::core::fmt::Debug + ::core::fmt::Display + ::std::any::Any + PkgCode
 {
     fn base(&self) -> ::core::option::Option<&dyn Pkg>;
     fn base_mut(&mut self) -> ::core::option::Option<&mut dyn Pkg>;
@@ -140,11 +144,15 @@ pub trait Pkg:
         self.check()?;
         self.install()
     }
+    fn hash(&self) -> Hash;
+    fn hash_code(&self) -> Hash;
 }
 
 pub trait PkgBuilder: ::std::any::Any {
     type Package;
-    fn default_unused(&mut self);
+    fn default_unused(
+        &mut self,
+    ) -> &mut dyn PkgBuilder<Package = Self::Package>;
     fn build(
         &mut self,
     ) -> Result<Self::Package, ::std::boxed::Box<dyn ::std::error::Error>>;
@@ -159,6 +167,12 @@ impl ::core::fmt::Display for PkgEmpty {
     }
 }
 
+impl PkgCode for PkgEmpty {
+    fn fmt(&self, _f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
+        Ok(())
+    }
+}
+
 impl Pkg for PkgEmpty {
     fn base(&self) -> Option<&dyn Pkg> {
         None
@@ -206,6 +220,18 @@ impl Pkg for PkgEmpty {
             ret = ::core::result::Result::Ok(());
         }
     }
+    fn hash(&self) -> Hash {
+        use ::sha3::Digest;
+        let mut hasher = ::sha3::Sha3_256::new();
+        let hash = hasher.finalize();
+        Hash::Sha3(hash)
+    }
+    fn hash_code(&self) -> Hash {
+        use ::sha3::Digest;
+        let mut hasher = ::sha3::Sha3_256::new();
+        let hash = hasher.finalize();
+        Hash::Sha3(hash)
+    }
 }
 
 ::bitflags::bitflags! {
@@ -240,9 +266,20 @@ impl Pkg for PkgEmpty {
 pub struct Conf {}
 
 /// package hash
+#[derive(Debug, Copy, Clone)]
 pub enum Hash {
     Sha3(::sha3::digest::Output<::sha3::Sha3_256>),
 }
+
+impl ::std::fmt::Display for Hash {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
+        match self {
+            //FIXME: move to something like zbase85
+            Hash::Sha3(h) => write!(f, "{:x}", h),
+        }
+    }
+}
+
 /*
 pub enum Value<T: Sized> {
     /// Set, only once per