diff --git a/packages/kos-mobile/src/lib.rs b/packages/kos-mobile/src/lib.rs
index 16600be..491ea39 100644
--- a/packages/kos-mobile/src/lib.rs
+++ b/packages/kos-mobile/src/lib.rs
@@ -2,9 +2,11 @@ pub mod number;
 
 use hex::FromHexError;
 use hex::ToHex;
-use kos::chains::{get_chain_by_base_id, Chain, ChainError, Transaction};
-use kos::crypto::cipher;
+use kos::chains::{
+    create_custom_evm, get_chain_by_base_id, Chain, ChainError, ChainOptions, Transaction,
+};
 use kos::crypto::cipher::CipherAlgo;
+use kos::crypto::{base64, cipher};
 
 uniffi::setup_scaffolding!();
 
@@ -49,6 +51,42 @@ struct KOSTransaction {
     pub signature: String,
 }
 
+#[derive(uniffi::Enum)]
+enum TransactionChainOptions {
+    Evm {
+        chain_id: u32,
+        network_type: u32,
+    },
+    Btc {
+        prev_scripts: Vec<Vec<u8>>,
+        input_amounts: Vec<u64>,
+    },
+}
+
+#[uniffi::export]
+fn new_bitcoin_transaction_options(
+    input_amounts: Vec<u64>,
+    prev_scripts: Vec<String>,
+) -> TransactionChainOptions {
+    let prev_scripts = prev_scripts
+        .iter()
+        .map(|s| base64::simple_base64_decode(s).unwrap_or_default())
+        .collect();
+
+    TransactionChainOptions::Btc {
+        prev_scripts,
+        input_amounts,
+    }
+}
+
+#[uniffi::export]
+fn new_evm_transaction_options(chain_id: u32, network_type: u32) -> TransactionChainOptions {
+    TransactionChainOptions::Evm {
+        chain_id,
+        network_type,
+    }
+}
+
 #[uniffi::export]
 fn generate_mnemonic(size: i32) -> Result<String, KOSError> {
     Ok(kos::crypto::mnemonic::generate_mnemonic(size as usize)?.to_phrase())
@@ -136,14 +174,48 @@ fn get_chain_by(id: u32) -> Result<Box<dyn Chain>, KOSError> {
 }
 
 #[uniffi::export]
-fn sign_transaction(account: KOSAccount, raw: String) -> Result<KOSTransaction, KOSError> {
-    let chain = get_chain_by(account.chain_id)?;
+fn sign_transaction(
+    account: KOSAccount,
+    raw: String,
+    options: Option<TransactionChainOptions>,
+) -> Result<KOSTransaction, KOSError> {
+    let options = match options {
+        Some(TransactionChainOptions::Evm {
+            chain_id,
+            network_type,
+        }) => Some(ChainOptions::EVM {
+            chain_id,
+            network_type,
+        }),
+        Some(TransactionChainOptions::Btc {
+            prev_scripts,
+            input_amounts,
+        }) => Some(ChainOptions::BTC {
+            prev_scripts,
+            input_amounts,
+        }),
+        None => None,
+    };
+
+    let mut chain = get_chain_by(account.chain_id)?;
+
+    if let Some(ChainOptions::EVM {
+        chain_id,
+        network_type,
+    }) = options
+    {
+        chain = create_custom_evm(chain_id, network_type).ok_or(KOSError::KOSDelegate(
+            "Failed to create custom evm chain".to_string(),
+        ))?;
+    }
+
     let raw_tx_bytes = hex::decode(raw.clone())?;
+
     let transaction = Transaction {
         raw_data: raw_tx_bytes,
         signature: Vec::new(),
         tx_hash: Vec::new(),
-        options: None,
+        options,
     };
     let pk = hex::decode(account.private_key.clone())?;
 
@@ -374,9 +446,9 @@ mod tests {
             0,
             false,
         )
-        .unwrap();
+            .unwrap();
 
-        let transaction = sign_transaction(account, raw.to_string()).unwrap();
+        let transaction = sign_transaction(account, raw.to_string(), None).unwrap();
 
         assert_eq!(transaction.chain_id, chain_id, "The chain_id doesn't match");
         assert_eq!(
diff --git a/packages/kos/src/chains/mod.rs b/packages/kos/src/chains/mod.rs
index 3c3397d..810b43c 100644
--- a/packages/kos/src/chains/mod.rs
+++ b/packages/kos/src/chains/mod.rs
@@ -363,7 +363,7 @@ impl ChainRegistry {
                 constants::BTC,
                 ChainInfo {
                     factory: || Box::new(btc::BTC::new()),
-                    supported: false,
+                    supported: true,
                 },
             ),
             (
@@ -384,7 +384,7 @@ impl ChainRegistry {
                 constants::LTC,
                 ChainInfo {
                     factory: || Box::new(btc::BTC::new_btc_based(5, "ltc", "LTC", "Litecoin")),
-                    supported: false,
+                    supported: true,
                 },
             ),
             (
@@ -419,7 +419,7 @@ impl ChainRegistry {
                 constants::SYS,
                 ChainInfo {
                     factory: || Box::new(btc::BTC::new_btc_based(15, "sys", "SYS", "Syscoin")),
-                    supported: false,
+                    supported: true,
                 },
             ),
             (
@@ -463,7 +463,7 @@ impl ChainRegistry {
                 constants::DGB,
                 ChainInfo {
                     factory: || Box::new(btc::BTC::new_btc_based(16, "dgb", "DGB", "Digibyte")),
-                    supported: false,
+                    supported: true,
                 },
             ),
             (
@@ -703,6 +703,15 @@ impl ChainRegistry {
         }
         ids
     }
+
+    fn create_custom_evm(&self, chain_id: u32, _network_type: u32) -> Option<Box<dyn Chain>> {
+        Some(Box::new(eth::ETH::new_eth_based(
+            0,
+            chain_id,
+            format!("ETH {}", chain_id).as_str(),
+            format!("Eth Based {}", chain_id).as_str(),
+        )))
+    }
 }
 
 pub fn get_chain_by_id(id: u32) -> Option<Box<dyn Chain>> {
@@ -745,3 +754,7 @@ pub fn is_chain_supported(id: u32) -> bool {
 pub fn get_supported_chains() -> Vec<u32> {
     ChainRegistry::new().get_supported_chains()
 }
+
+pub fn create_custom_evm(chain_id: u32, network_type: u32) -> Option<Box<dyn Chain>> {
+    ChainRegistry::new().create_custom_evm(chain_id, network_type)
+}