diff --git a/src/storage_proofs.rs b/src/storage_proofs.rs
index cb06ff6..f93c0c1 100644
--- a/src/storage_proofs.rs
+++ b/src/storage_proofs.rs
@@ -134,3 +134,89 @@ impl StorageProofs {
         Ok(())
     }
 }
+
+
+#[cfg(test)]
+mod tests {
+    use ark_std::rand::{distributions::Alphanumeric, rngs::ThreadRng, Rng};
+    use rs_poseidon::poseidon::hash;
+    use ruint::aliases::U256;
+
+    use crate::circuit_tests::utils::{digest, treehash};
+
+    use rmpv::Value;
+    use rmpv::encode::write_value;
+    use rmpv::decode::read_value;
+
+    #[test]
+    fn test_mpack() {
+        let mut buf = Vec::new();
+        let val = Value::from("le message");
+
+        // example of serializing the random chunk data
+        // we build them up in mpack Value enums
+        let data = (0..4)
+            .map(|_| {
+                let rng = ThreadRng::default();
+                let preimages: Vec<U256> = rng
+                    .sample_iter(Alphanumeric)
+                    .take(256)
+                    .map(|c| U256::from(c))
+                    .collect();
+                let hash = digest(&preimages, Some(16));
+                (preimages, hash)
+            })
+            .collect::<Vec<(Vec<U256>, U256)>>();
+
+        let chunks = data.iter()
+            .map(|c| {
+                let x = c.0.iter()
+                    .map(|c| Value::Ext(50, c.to_le_bytes_vec()))
+                    .collect::<Vec<Value>>();
+                Value::Array(x)
+            })
+            .collect::<Vec<Value>>();
+        let chunks = Value::Array(chunks);
+        let mut data = Value::Map(vec![(Value::String("chunks".into()), chunks.clone() )]);
+
+        println!("Debug: chunks: {:?}", chunks[0][0]);
+
+        // Serialize the value types to an array pointer
+        write_value(&mut buf, &data).unwrap();
+        let mut rd = &buf[..];
+        
+        let args = read_value(&mut rd).unwrap();
+
+        assert!(Value::is_map(&args));
+        assert!(Value::is_array(&args["chunks"]));
+        assert!(Value::is_array(&args["chunks"][0]));
+        let mut arg_chunks: Vec<Vec<U256>> = Vec::new();
+
+        // deserialize the data back into u256's
+        // instead of this, we'll want to use `builder.push_input`
+        args["chunks"]
+            .as_array()
+            .unwrap()
+            .iter()
+            .for_each(|c| {
+                if let Some(x) = c.as_array() {
+                    let mut vals: Vec<U256> = Vec::new();
+                    x.iter().for_each(|n| {
+                        let b = n.as_ext().unwrap();
+                        // ensure it's a LE uin256 which we've set as ext 50
+                        assert_eq!(b.0, 50);
+                        vals.push(U256::try_from_le_slice(b.1).unwrap());
+                        // TODO: change to use
+                        // builder.push_input("hashes", *c)
+                    });
+                    arg_chunks.push(vals);
+                } else {
+                    panic!("unhandled type!");
+                }
+            });
+
+        assert_eq!(arg_chunks.len(), 4);
+        assert_eq!(arg_chunks[0].len(), 256);
+
+    }
+}