diff --git a/src/opcode.rs b/src/opcode.rs
index f00577f..8dfee56 100644
--- a/src/opcode.rs
+++ b/src/opcode.rs
@@ -162,14 +162,104 @@ impl Opcode {
     pub const SWAP15: Opcode = Opcode(0x9e);
     pub const SWAP16: Opcode = Opcode(0x9f);
 
-    /// `RETURN`
     pub const RETURN: Opcode = Opcode(0xf3);
-    /// `REVERT`
+
     pub const REVERT: Opcode = Opcode(0xfd);
 
-    /// `INVALID`
     pub const INVALID: Opcode = Opcode(0xfe);
 
-    /// See [EIP-3541](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-3541.md)
     pub const EOFMAGIC: Opcode = Opcode(0xef);
 }
+// External opcodes
+impl Opcode {
+    /// `SHA3`
+    pub const SHA3: Opcode = Opcode(0x20);
+    /// `ADDRESS`
+    pub const ADDRESS: Opcode = Opcode(0x30);
+    /// `BALANCE`
+    pub const BALANCE: Opcode = Opcode(0x31);
+    /// `SELFBALANCE`
+    pub const SELFBALANCE: Opcode = Opcode(0x47);
+    /// `BASEFEE`
+    pub const BASEFEE: Opcode = Opcode(0x48);
+    /// `ORIGIN`
+    pub const ORIGIN: Opcode = Opcode(0x32);
+    /// `CALLER`
+    pub const CALLER: Opcode = Opcode(0x33);
+    /// `CALLVALUE`
+    pub const CALLVALUE: Opcode = Opcode(0x34);
+    /// `GASPRICE`
+    pub const GASPRICE: Opcode = Opcode(0x3a);
+    /// `EXTCODESIZE`
+    pub const EXTCODESIZE: Opcode = Opcode(0x3b);
+    /// `EXTCODECOPY`
+    pub const EXTCODECOPY: Opcode = Opcode(0x3c);
+    /// `EXTCODEHASH`
+    pub const EXTCODEHASH: Opcode = Opcode(0x3f);
+    /// `RETURNDATASIZE`
+    pub const RETURNDATASIZE: Opcode = Opcode(0x3d);
+    /// `RETURNDATACOPY`
+    pub const RETURNDATACOPY: Opcode = Opcode(0x3e);
+    /// `BLOCKHASH`
+    pub const BLOCKHASH: Opcode = Opcode(0x40);
+    /// `COINBASE`
+    pub const COINBASE: Opcode = Opcode(0x41);
+    /// `TIMESTAMP`
+    pub const TIMESTAMP: Opcode = Opcode(0x42);
+    /// `NUMBER`
+    pub const NUMBER: Opcode = Opcode(0x43);
+    /// `DIFFICULTY`
+    pub const DIFFICULTY: Opcode = Opcode(0x44);
+    /// `GASLIMIT`
+    pub const GASLIMIT: Opcode = Opcode(0x45);
+    /// `SLOAD`
+    pub const SLOAD: Opcode = Opcode(0x54);
+    /// `SSTORE`
+    pub const SSTORE: Opcode = Opcode(0x55);
+    /// `GAS`
+    pub const GAS: Opcode = Opcode(0x5a);
+    /// `LOGn`
+    pub const LOG0: Opcode = Opcode(0xa0);
+    pub const LOG1: Opcode = Opcode(0xa1);
+    pub const LOG2: Opcode = Opcode(0xa2);
+    pub const LOG3: Opcode = Opcode(0xa3);
+    pub const LOG4: Opcode = Opcode(0xa4);
+    /// `CREATE`
+    pub const CREATE: Opcode = Opcode(0xf0);
+    /// `CREATE2`
+    pub const CREATE2: Opcode = Opcode(0xf5);
+    /// `CALL`
+    pub const CALL: Opcode = Opcode(0xf1);
+    /// `CALLCODE`
+    pub const CALLCODE: Opcode = Opcode(0xf2);
+    /// `DELEGATECALL`
+    pub const DELEGATECALL: Opcode = Opcode(0xf4);
+    /// `STATICCALL`
+    pub const STATICCALL: Opcode = Opcode(0xfa);
+    /// `SUICIDE`
+    pub const SUICIDE: Opcode = Opcode(0xff);
+    /// `CHAINID`
+    pub const CHAINID: Opcode = Opcode(0x46);
+}
+
+impl Opcode {
+    /// Whether the opcode is a push opcode.
+    pub fn is_push(&self) -> Option<u8> {
+        let value = self.0;
+        if (0x60..=0x7f).contains(&value) {
+            Some(value - 0x60 + 1)
+        } else {
+            None
+        }
+    }
+
+    #[inline]
+    pub const fn as_u8(&self) -> u8 {
+        self.0
+    }
+
+    #[inline]
+    pub const fn as_usize(&self) -> usize {
+        self.0 as usize
+    }
+}