diff --git a/rust-toolchain b/rust-toolchain
new file mode 100644
index 0000000..d309aeb
--- /dev/null
+++ b/rust-toolchain
@@ -0,0 +1 @@
+nightly-2023-06-01
\ No newline at end of file
diff --git a/src/matrix.rs b/src/matrix.rs
index 9207835..e3593ae 100644
--- a/src/matrix.rs
+++ b/src/matrix.rs
@@ -3,7 +3,6 @@
 //! with the intention of construction of parameters and are not used in the
 //! actual permutation process.
 
-
 use halo2_proofs::arithmetic::FieldExt;
 
 #[derive(PartialEq, Debug, Clone)]
diff --git a/src/poseidon.rs b/src/poseidon.rs
index 163c1fe..99aed04 100644
--- a/src/poseidon.rs
+++ b/src/poseidon.rs
@@ -1,12 +1,13 @@
 use crate::{Spec, State};
 use halo2_proofs::arithmetic::FieldExt;
+use std::sync::Arc;
 
 /// Poseidon hasher that maintains state and inputs and yields single element
 /// output when desired
 #[derive(Debug, Clone)]
 pub struct Poseidon<F: FieldExt, const T: usize, const RATE: usize> {
     state: State<F, T>,
-    spec: Spec<F, T, RATE>,
+    spec: Arc<Spec<F, T, RATE>>,
     absorbing: Vec<F>,
 }
 
@@ -14,7 +15,7 @@ impl<F: FieldExt, const T: usize, const RATE: usize> Poseidon<F, T, RATE> {
     /// Constructs a clear state poseidon instance
     pub fn new(r_f: usize, r_p: usize) -> Self {
         Self {
-            spec: Spec::new(r_f, r_p),
+            spec: Arc::new(Spec::new(r_f, r_p)),
             state: State::default(),
             absorbing: Vec::new(),
         }
@@ -26,6 +27,16 @@ impl<F: FieldExt, const T: usize, const RATE: usize> Poseidon<F, T, RATE> {
         self.absorbing = Vec::new();
     }
 
+    /// return share spec
+    pub fn get_spec(&self) -> Arc<Spec<F, T, RATE>> {
+        self.spec.clone()
+    }
+
+    /// get the internal state spec
+    pub fn get_state(&self) -> [F; T] {
+        self.state.0.clone()
+    }
+
     /// Update n = RATE elements
     /// This assumes the current absorbing list is empty
     pub fn update_exact(&mut self, elements: &[F; RATE]) -> F {
diff --git a/src/spec.rs b/src/spec.rs
index 01a91e8..e78a9d7 100644
--- a/src/spec.rs
+++ b/src/spec.rs
@@ -397,8 +397,8 @@ impl<F: FieldExt, const T: usize, const RATE: usize> Spec<F, T, RATE> {
 
 #[cfg(test)]
 pub(super) mod tests {
-    
-use halo2_proofs::arithmetic::FieldExt;
+
+    use halo2_proofs::arithmetic::FieldExt;
 
     use super::MDSMatrix;
     use crate::grain::Grain;