diff --git a/src/MetaDataAPI/LambdaFunction.cs b/src/MetaDataAPI/LambdaFunction.cs
index daeee90c..4d518db0 100644
--- a/src/MetaDataAPI/LambdaFunction.cs
+++ b/src/MetaDataAPI/LambdaFunction.cs
@@ -29,9 +29,15 @@ public LambdaResponse FunctionHandler(LambdaRequest request, ILambdaLogger logge
     {
         try
         {
-            if (request.ValidationResult != null) return new ValidationErrorResponse(request.ValidationResult);
-
-            var chainInfo = chainManager.FetchChainInfo(request.ChainId);
+            if (request.ValidationResult != null)
+            {
+                return new ValidationErrorResponse(request.ValidationResult);
+            }
+
+            if (!chainManager.TryFetchChainInfo(request.ChainId, out var chainInfo))
+            {
+                return new ChainNotSupportedResponse(request.ChainId);
+            }
 
             var poolsInfo = AbstractProvider.FetchPoolInfo(request.PoolId, chainInfo);
 
diff --git a/src/MetaDataAPI/Response/ChainNotSupportedResponse.cs b/src/MetaDataAPI/Response/ChainNotSupportedResponse.cs
new file mode 100644
index 00000000..d45f4ba1
--- /dev/null
+++ b/src/MetaDataAPI/Response/ChainNotSupportedResponse.cs
@@ -0,0 +1,14 @@
+using System.Net;
+using System.Numerics;
+
+namespace MetaDataAPI.Response;
+
+public class ChainNotSupportedResponse : LambdaResponse
+{
+    public ChainNotSupportedResponse(BigInteger chainId)
+        : base(
+            body: $"ChainID {chainId} is not supported.",
+            statusCode: HttpStatusCode.NotImplemented
+        )
+    { }
+}
\ No newline at end of file
diff --git a/src/MetaDataAPI/Services/ChainsInfo/IChainManager.cs b/src/MetaDataAPI/Services/ChainsInfo/IChainManager.cs
index ad363145..8516ada4 100644
--- a/src/MetaDataAPI/Services/ChainsInfo/IChainManager.cs
+++ b/src/MetaDataAPI/Services/ChainsInfo/IChainManager.cs
@@ -1,8 +1,9 @@
 using System.Numerics;
+using System.Diagnostics.CodeAnalysis;
 
 namespace MetaDataAPI.Services.ChainsInfo;
 
 public interface IChainManager
 {
-    public ChainInfo FetchChainInfo(BigInteger chainId);
+    public bool TryFetchChainInfo(BigInteger chainId, [MaybeNullWhen(false)] out ChainInfo chainInfo);
 }
\ No newline at end of file
diff --git a/src/MetaDataAPI/Services/ChainsInfo/LocalChainManager.cs b/src/MetaDataAPI/Services/ChainsInfo/LocalChainManager.cs
index 99e96329..54d720e5 100644
--- a/src/MetaDataAPI/Services/ChainsInfo/LocalChainManager.cs
+++ b/src/MetaDataAPI/Services/ChainsInfo/LocalChainManager.cs
@@ -1,4 +1,5 @@
 using System.Numerics;
+using System.Diagnostics.CodeAnalysis;
 
 namespace MetaDataAPI.Services.ChainsInfo;
 
@@ -9,8 +10,8 @@ public class LocalChainManager : IChainManager
         { 97, new ChainInfo(97, "https://data-seed-prebsc-1-s1.binance.org:8545/", "0xe42876a77108E8B3B2af53907f5e533Cba2Ce7BE") }
     };
 
-    public ChainInfo FetchChainInfo(BigInteger chainId)
+    public bool TryFetchChainInfo(BigInteger chainId, [MaybeNullWhen(false)] out ChainInfo chainInfo)
     {
-        return localChainInfo[chainId];
+        return localChainInfo.TryGetValue(chainId, out chainInfo);
     }
 }
\ No newline at end of file