diff --git a/src/eco/Oracle.sol b/src/eco/Oracle.sol
index f35af70..f1435f8 100644
--- a/src/eco/Oracle.sol
+++ b/src/eco/Oracle.sol
@@ -27,6 +27,7 @@ contract Oracle is Verifier {
     event SetApproved(address operator, bool approve);
 
     address public immutable PROTOCOL;
+    address public immutable SUBAPI;
 
     address public owner;
     // chainId => price
@@ -45,7 +46,8 @@ contract Oracle is Verifier {
         _;
     }
 
-    constructor(address dao, address ormp) {
+    constructor(address dao, address ormp, address subapi) {
+        SUBAPI = subapi;
         PROTOCOL = ormp;
         owner = dao;
     }
@@ -75,11 +77,6 @@ contract Oracle is Verifier {
         emit SetFee(chainId, fee_);
     }
 
-    function setDapi(uint256 chainId, address dapi) external onlyOwner {
-        dapiOf[chainId] = dapi;
-        emit SetDapi(chainId, dapi);
-    }
-
     function fee(uint256 toChainId, address /*ua*/ ) public view returns (uint256) {
         return feeOf[toChainId];
     }
@@ -90,7 +87,6 @@ contract Oracle is Verifier {
     }
 
     function merkleRoot(uint256 chainId, uint256 /*blockNumber*/ ) public view override returns (bytes32) {
-        address dapi = dapiOf[chainId];
-        return IFeedOracle(dapi).messageRoot();
+        return IFeedOracle(SUBAPI).messageRootOf(chainId);
     }
 }
diff --git a/src/interfaces/IFeedOracle.sol b/src/interfaces/IFeedOracle.sol
index b38fb15..5fa5851 100644
--- a/src/interfaces/IFeedOracle.sol
+++ b/src/interfaces/IFeedOracle.sol
@@ -18,5 +18,5 @@
 pragma solidity 0.8.17;
 
 interface IFeedOracle {
-    function messageRoot() external view returns (bytes32);
+    function messageRootOf(uint256 chainid) external view returns (bytes32);
 }
diff --git a/test/bench/ORMP.b.sol b/test/bench/ORMP.b.sol
index 3247ab6..d16a7f9 100644
--- a/test/bench/ORMP.b.sol
+++ b/test/bench/ORMP.b.sol
@@ -74,15 +74,15 @@ contract ORMPBenchmarkTest is Test {
             Verifier.Proof({blockNumber: block.number, messageIndex: message.index, messageProof: ormp.prove()});
 
         vm.createSelectFork(message.toChainId.toChainName());
+        // TODO: setDefaltOracle
         vm.store(address(oracle), bytes32(uint256(0)), bytes32(uint256(uint160(self))));
         assertEq(oracle.owner(), self);
-        oracle.setDapi(message.fromChainId, self);
 
         vm.prank(address(relayer));
         ormp.recv(message, abi.encode(proof));
     }
 
-    function messageRoot() public view returns (bytes32) {
+    function messageRootOf(uint256) external view returns (bytes32) {
         return root;
     }
 
diff --git a/test/eco/Oracle.t.sol b/test/eco/Oracle.t.sol
index 6a1bec7..e65bb27 100644
--- a/test/eco/Oracle.t.sol
+++ b/test/eco/Oracle.t.sol
@@ -27,7 +27,7 @@ contract OracleTest is Test {
     receive() external payable {}
 
     function setUp() public {
-        oracle = new Oracle(self, self);
+        oracle = new Oracle(self, self, self);
         oracle.setApproved(self, true);
     }
 
@@ -66,28 +66,17 @@ contract OracleTest is Test {
         oracle.setFee(1, 1);
     }
 
-    function test_setDapi() public {
-        oracle.setDapi(1, address(1));
-        assertEq(oracle.dapiOf(1), address(1));
-    }
-
-    function testFail_setDapi() public {
-        vm.prank(address(1));
-        oracle.setDapi(1, address(1));
-    }
-
     function test_assign() public {
         oracle.setFee(1, 1);
         oracle.assign{value: 1}(bytes32(0));
     }
 
     function test_merkleRoot() public {
-        oracle.setDapi(1, self);
         bytes32 r = oracle.merkleRoot(1, 1);
         assertEq(r, bytes32(uint256(1)));
     }
 
-    function messageRoot() external pure returns (bytes32) {
+    function messageRootOf(uint256) external pure returns (bytes32) {
         return bytes32(uint256(1));
     }
 }