diff --git a/json/src/blockchain/blockchain.rs b/json/src/blockchain/blockchain.rs
index 8c67799e1..75d321a4d 100644
--- a/json/src/blockchain/blockchain.rs
+++ b/json/src/blockchain/blockchain.rs
@@ -20,6 +20,7 @@ use bytes::Bytes;
 use blockchain::state::State;
 use blockchain::header::Header;
 use blockchain::block::Block;
+use spec::Genesis;
 
 /// Blockchain deserialization.
 #[derive(Debug, PartialEq, Deserialize)]
@@ -45,6 +46,21 @@ impl BlockChain {
 	pub fn blocks_rlp(&self) -> Vec<Vec<u8>> {
 		self.blocks.iter().map(|block| block.rlp()).collect()
 	}
+
+	/// Returns spec compatible genesis struct.
+	pub fn genesis(&self) -> Genesis {
+		Genesis {
+			nonce: Some(self.genesis_block.nonce.clone()),
+			mix_hash: Some(self.genesis_block.mix_hash.clone()),
+			seal_fields: None,
+			seal_rlp: None,
+			difficulty: self.genesis_block.difficulty,
+			author: self.genesis_block.author.clone(),
+			timestamp: self.genesis_block.timestamp,
+			parent_hash: self.genesis_block.parent_hash.clone(),
+			gas_limit: self.genesis_block.gas_limit,
+		}
+	}
 }
 
 #[cfg(test)]
diff --git a/json/src/blockchain/header.rs b/json/src/blockchain/header.rs
index e97039213..f4ebee01b 100644
--- a/json/src/blockchain/header.rs
+++ b/json/src/blockchain/header.rs
@@ -23,31 +23,48 @@ use bytes::Bytes;
 /// Blockchain test header deserializer.
 #[derive(Debug, PartialEq, Deserialize)]
 pub struct Header {
-	bloom: Bloom,
-	coinbase: Address,
-	difficulty: Uint,
+	/// Blocks bloom.
+	pub bloom: Bloom,
+	/// Blocks author.
+	#[serde(rename="coinbase")]
+	pub author: Address,
+	/// Difficulty.
+	pub difficulty: Uint,
 	#[serde(rename="extraData")]
-	extra_data: Bytes,
+	/// Extra data.
+	pub extra_data: Bytes,
+	/// Gas limit.
 	#[serde(rename="gasLimit")]
-	gas_limit: Uint,
+	pub gas_limit: Uint,
+	/// Gas used.
 	#[serde(rename="gasUsed")]
-	gas_used: Uint,
-	hash: H256,
+	pub gas_used: Uint,
+	/// Hash.
+	pub hash: H256,
 	#[serde(rename="mixHash")]
-	mix_hash: H256,
-	nonce: H64,
-	number: Uint,
+	/// Mix hash.
+	pub mix_hash: H256,
+	/// Seal nonce.
+	pub nonce: H64,
+	/// Block number.
+	pub number: Uint,
+	/// Parent hash.
 	#[serde(rename="parentHash")]
-	parent_hash: H256,
+	pub parent_hash: H256,
+	/// Receipt root.
 	#[serde(rename="receiptTrie")]
-	receipt_trie: H256,
+	pub receipt_root: H256,
+	/// State root.
 	#[serde(rename="stateRoot")]
-	state_root: H256,
-	timestamp: Uint,
+	pub state_root: H256,
+	/// Timestamp.
+	pub timestamp: Uint,
+	/// Transactions root.
 	#[serde(rename="transactionsTrie")]
-	transactions_trie: H256,
+	pub transactions_root: H256,
+	/// Uncles hash.
 	#[serde(rename="uncleHash")]
-	uncle_hash: H256,
+	pub uncles_hash: H256,
 }
 
 #[cfg(test)]
diff --git a/json/src/hash.rs b/json/src/hash.rs
index bece68011..c555b6266 100644
--- a/json/src/hash.rs
+++ b/json/src/hash.rs
@@ -25,7 +25,7 @@ use util::hash::{H64 as Hash64, Address as Hash160, H256 as Hash256, H2048 as Ha
 macro_rules! impl_hash {
 	($name: ident, $inner: ident) => {
 		/// Lenient hash json deserialization for test json files.
-		#[derive(Default, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+		#[derive(Default, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, Clone)]
 		pub struct $name($inner);
 
 		impl Into<$inner> for $name {
diff --git a/json/src/spec/genesis.rs b/json/src/spec/genesis.rs
index 4c66a9e35..a8b5b30e3 100644
--- a/json/src/spec/genesis.rs
+++ b/json/src/spec/genesis.rs
@@ -17,30 +17,39 @@
 //! Spec genesis deserialization.
 
 use uint::Uint;
-use hash::{Address, H256};
+use hash::{H64, Address, H256};
 use bytes::Bytes;
 
 /// Spec genesis.
 #[derive(Debug, PartialEq, Deserialize)]
 pub struct Genesis {
 	// old seal
-	nonce: Option<Uint>,
+	/// Seal nonce.
+	pub nonce: Option<H64>,
 	#[serde(rename="mixHash")]
-	mix_hash: Option<H256>,
+	/// Seal mix hash.
+	pub mix_hash: Option<H256>,
 
 	// new seal // TODO: consider moving it to a separate seal structure
 	#[serde(rename="sealFields")]
-	seal_fields: Option<Uint>,
+	/// Number of seal fields.
+	pub seal_fields: Option<Uint>,
 	#[serde(rename="sealRlp")]
-	seal_rlp: Option<Bytes>,
+	/// Seal rlp.
+	pub seal_rlp: Option<Bytes>,
 
-	difficulty: Uint,
-	author: Address,
-	timestamp: Uint,
+	/// Difficulty.
+	pub difficulty: Uint,
+	/// Block author.
+	pub author: Address,
+	/// Block timestamp.
+	pub timestamp: Uint,
+	/// Parent hash.
 	#[serde(rename="parentHash")]
-	parent_hash: H256,
+	pub parent_hash: H256,
+	/// Gas limit.
 	#[serde(rename="gasLimit")]
-	gas_limit: Uint,
+	pub gas_limit: Uint,
 }
 
 #[cfg(test)]
diff --git a/json/src/uint.rs b/json/src/uint.rs
index 41e717277..2d24c3f7e 100644
--- a/json/src/uint.rs
+++ b/json/src/uint.rs
@@ -22,7 +22,7 @@ use serde::de::Visitor;
 use util::numbers::{U256, Uint as U};
 
 /// Lenient uint json deserialization for test json files.
-#[derive(Default, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Default, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)]
 pub struct Uint(U256);
 
 impl Into<U256> for Uint {