Add CURRENCY_API_KEY option to config files

backend/src/__fixtures__/mempool-config.template.json

@@ -37,7 +37,8 @@
     "MAX_PUSH_TX_SIZE_WEIGHT": 4000000,
     "ALLOW_UNREACHABLE": true,
     "PRICE_UPDATES_PER_HOUR": 1,
-    "MAX_TRACKED_ADDRESSES": 1
+    "MAX_TRACKED_ADDRESSES": 1,
+    "CURRENCY_API_KEY": "__MEMPOOL_CURRENCY_API_KEY__"
   },
   "CORE_RPC": {
     "HOST": "__CORE_RPC_HOST__",

backend/src/__tests__/config.test.ts

@@ -51,6 +51,7 @@ describe('Mempool Backend Config', () => {
         ALLOW_UNREACHABLE: true,
         PRICE_UPDATES_PER_HOUR: 1,
         MAX_TRACKED_ADDRESSES: 1,
+        CURRENCY_API_KEY: ''
       });
 
       expect(config.ELECTRUM).toStrictEqual({ HOST: '127.0.0.1', PORT: 3306, TLS_ENABLED: true });

backend/src/config.ts

@@ -42,6 +42,7 @@ interface IConfig {
     ALLOW_UNREACHABLE: boolean;
     PRICE_UPDATES_PER_HOUR: number;
     MAX_TRACKED_ADDRESSES: number;
+    CURRENCY_API_KEY: string;
   };
   ESPLORA: {
     REST_API_URL: string;
@@ -200,6 +201,7 @@ const defaults: IConfig = {
     'ALLOW_UNREACHABLE': true,
     'PRICE_UPDATES_PER_HOUR': 1,
     'MAX_TRACKED_ADDRESSES': 1,
+    'CURRENCY_API_KEY': '',
   },
   'ESPLORA': {
     'REST_API_URL': 'http://127.0.0.1:3000',