diff --git a/.env.example b/.env.example
index 0cbf2b0..b9bcff0 100644
--- a/.env.example
+++ b/.env.example
@@ -6,3 +6,6 @@ SUPABASE_SERVICE_ROLE_KEY=your-service-role-key
 # Circle
 CIRCLE_API_KEY=your-circle-api-key
 CIRCLE_ENTITY_SECRET=your-circle-entity-secret
+
+# Arc Testnet
+ARC_TESTNET_RPC_KEY=your-arc-testnet-rpc-key
diff --git a/README.md b/README.md
index 9e2498f..5adee84 100644
--- a/README.md
+++ b/README.md
@@ -106,6 +106,7 @@ CIRCLE_ENTITY_SECRET=your-circle-entity-secret
 | `SUPABASE_SERVICE_ROLE_KEY` | Server-side | Supabase service role key for admin operations. |
 | `CIRCLE_API_KEY` | Server-side | Circle API key for wallet operations. |
 | `CIRCLE_ENTITY_SECRET` | Server-side | Circle entity secret for signing transactions. |
+| `ARC_TESTNET_RPC_KEY` | Server-side | Arc Testnet RPC key. Get from https://rpc.testnet.arc.network |
 
 ## User Accounts
 
diff --git a/lib/circle/gateway-sdk.ts b/lib/circle/gateway-sdk.ts
index 25552ff..a855501 100644
--- a/lib/circle/gateway-sdk.ts
+++ b/lib/circle/gateway-sdk.ts
@@ -39,7 +39,10 @@ import {
 export const GATEWAY_WALLET_ADDRESS = "0x0077777d7EBA4688BDeF3E311b846F25870A19B9";
 export const GATEWAY_MINTER_ADDRESS = "0x0022222ABE238Cc2C7Bb1f21003F0a260052475B";
 
-const arcRpcKey = process.env.ARC_TESTNET_RPC_KEY || 'c0ca2582063a5bbd5db2f98c139775e982b16919';
+const arcRpcKey = process.env.ARC_TESTNET_RPC_KEY;
+if (!arcRpcKey) {
+  console.warn('[arc-fintech] ARC_TESTNET_RPC_KEY is not set. Add it to .env.local. See .env.example.');
+}
 
 export const arcTestnet = {
   id: 5042002,