diff --git a/README.md b/README.md
index acbb1900..ed92fc57 100644
--- a/README.md
+++ b/README.md
@@ -90,6 +90,11 @@ Raito is a reference to Light Yagami (夜神月, Yagami Raito) from the manga/an
 
 ![Raito and Raito](./docs/img/memes/raito_shinigami_fusion.jpg)
 
+# Contact
+
+* [Raito Telegram](https://t.me/RaitoStarknet)
+* [Raito OnlyDust](https://app.onlydust.com/p/raito---bitcoin-zk-client)
+
 ## Usage
 
 This will compile all the components:
diff --git a/src/lib.cairo b/src/lib.cairo
index ce41db81..7778f44f 100644
--- a/src/lib.cairo
+++ b/src/lib.cairo
@@ -1,5 +1,4 @@
-pub mod utils;
+mod utils;
 pub mod validation;
-
 mod state;
 mod main;
diff --git a/src/state.cairo b/src/state.cairo
index 2f5e3653..6fcaf700 100644
--- a/src/state.cairo
+++ b/src/state.cairo
@@ -75,8 +75,6 @@ pub struct Header {
     pub version: u32,
     /// The hash of the previous block in the blockchain.
     pub prev_block_hash: u256,
-    /// The Merkle root hash of the transactions in the block.
-    pub merkle_root_hash: u256,
     /// The timestamp of the block.
     pub time: u32,
     /// The difficulty target for mining the block.
diff --git a/src/validation.cairo b/src/validation.cairo
index d88aa3ea..ce17c749 100644
--- a/src/validation.cairo
+++ b/src/validation.cairo
@@ -1,6 +1,5 @@
-use super::state::{Block, ChainState, UtreexoState};
-use raito::utils::shl;
-use raito::utils::shr;
+use super::utils::{shl, shr};
+use super::state::{Block, ChainState, Transaction, UtreexoState};
 
 const MAX_TARGET: u256 = 0x00000000FFFF0000000000000000000000000000000000000000000000000000;
 
@@ -12,19 +11,47 @@ impl BlockValidatorImpl of BlockValidator {
         validate_target(@self, @block)?;
         validate_timestamp(@self, @block)?;
 
-        validate_merkle_root(@self, @block)?;
-        // validate_and_apply_transactions
+        let (total_fees, merkle_root) = fee_and_merkle_root(@self, @block)?;
 
+        validate_coinbase(@block, total_fees)?;
+
+        let best_block_hash = block_hash(@block, merkle_root)?;
         let prev_timestamps = next_prev_timestamps(@self, @block);
         let total_work = compute_total_work(@self, @block);
         let (current_target, epoch_start_time) = adjust_difficulty(@self, @block);
+        let block_height = self.block_height + 1;
 
         Result::Ok(
-            ChainState { total_work, current_target, epoch_start_time, prev_timestamps, ..self, }
+            ChainState {
+                block_height,
+                total_work,
+                best_block_hash,
+                current_target,
+                epoch_start_time,
+                prev_timestamps,
+                ..self,
+            }
         )
     }
 }
 
+#[generate_trait]
+impl TransactionValidatorImpl of TransactionValidator {
+    fn txid(self: @Transaction) -> u256 {
+        // TODO: implement
+        0
+    }
+    fn fee(self: @Transaction) -> u256 {
+        // TODO: implement
+        0
+    }
+}
+
+fn block_hash(block: @Block, merkle_root: u256) -> Result<u256, ByteArray> {
+    // TODO: implement
+    Result::Ok(0)
+}
+
 fn validate_prev_block_hash(self: @ChainState, block: @Block) -> Result<(), ByteArray> {
     if self.best_block_hash == block.header.prev_block_hash {
         Result::Ok(())
@@ -124,6 +151,28 @@ pub fn target_to_bits(target: u256) -> Result<u32, felt252> {
     Result::Ok(result)
 }
 
+fn fee_and_merkle_root(self: @ChainState, block: @Block) -> Result<(u256, u256), ByteArray> {
+    let mut txids = ArrayTrait::new();
+    let mut total_fee = 0;
+
+    for tx in *block.txs {
+        txids.append(tx.txid());
+        total_fee += tx.fee();
+    };
+
+    Result::Ok((total_fee, merkle_root(txids)))
+}
+
+fn merkle_root(txids: Array<u256>) -> u256 {
+    // TODO: implement
+    0
+}
+
+fn validate_coinbase(block: @Block, total_fees: u256) -> Result<(), ByteArray> {
+    //TODO implement
+    Result::Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::{validate_target, validate_timestamp, validate_proof_of_work};
@@ -142,9 +191,7 @@ mod tests {
             utreexo_state: UtreexoState { roots: array![].span() },
         };
         let mut block = Block {
-            header: Header {
-                version: 1, prev_block_hash: 1, merkle_root_hash: 1, time: 1, bits: 1, nonce: 1,
-            },
+            header: Header { version: 1, prev_block_hash: 1, time: 1, bits: 1, nonce: 1, },
             txs: ArrayTrait::new().span(),
         };
 
@@ -174,9 +221,7 @@ mod tests {
             utreexo_state: UtreexoState { roots: array![].span() },
         };
         let mut block = Block {
-            header: Header {
-                version: 1, prev_block_hash: 1, merkle_root_hash: 1, time: 12, bits: 1, nonce: 1,
-            },
+            header: Header { version: 1, prev_block_hash: 1, time: 12, bits: 1, nonce: 1, },
             txs: ArrayTrait::new().span(),
         };
 
@@ -198,9 +243,7 @@ mod tests {
     #[test]
     fn test_validate_proof_of_work() {
         let mut block = Block {
-            header: Header {
-                version: 1, prev_block_hash: 1, merkle_root_hash: 1, time: 12, bits: 1, nonce: 1,
-            },
+            header: Header { version: 1, prev_block_hash: 1, time: 12, bits: 1, nonce: 1, },
             txs: ArrayTrait::new().span(),
         };
 
diff --git a/tests/tests.cairo b/tests/tests.cairo
index 76c15f51..0646d0a5 100644
--- a/tests/tests.cairo
+++ b/tests/tests.cairo
@@ -1,6 +1,3 @@
-use core::result::ResultTrait;
-use core::option::OptionTrait;
-use core::traits::Into;
 use raito::validation::target_to_bits;
 
 #[test]