rosen-bridge · mgpai22 · Apr 22, 2026 · Apr 23, 2026 · Apr 23, 2026
diff --git a/.changeset/base-watcher-support.md b/.changeset/base-watcher-support.md
@@ -0,0 +1,5 @@
+---
+'@rosen-bridge/watcher': minor
+---
+
+Add Base watcher support and switch the default Base RPC config to a production-provider placeholder.
diff --git a/config/default.yaml b/config/default.yaml
@@ -1,5 +1,5 @@
 ---
-network: '' # which scanner network used in this watcher ergo/cardano/bitcoin/ethereum
+network: '' # which scanner network used in this watcher ergo/cardano/bitcoin/base/ethereum
 observation:
   # confirmation: 60 # number of required block confirmations to create the commitment after observing an event
   validThreshold: 259200 # Observations that have not been triggered will not be processed after this period (in seconds, converted to block count based on selected network block time)
@@ -58,6 +58,15 @@ cardano:
     projectId: '' # blockfrost project Id
     timeout: 10 # blockfrost request timeout
     interval: 20 # blockfrost check timeout
+base:
+  type: '' # options: rpc
+  initial:
+    height: -1 # initial height of scanning
+  interval: 20 # scanning interval (in seconds)
+  rpc:
+    url: '' # rpc url (use a production provider; the public Base endpoint is rate-limited)
+    timeout: 10 # rpc request timeout (in seconds)
+    # authToken: # rpc auth token
 ethereum:
   type: '' # options: rpc
   initial:

diff --git a/docker/custom-environment-variables.yaml b/docker/custom-environment-variables.yaml
@@ -24,6 +24,9 @@ cardano:
     authToken: 'KOIOS_AUTH_TOKEN'
   blockfrost:
     projectId: 'BLOCKFROST_PROJECT_ID'
+base:
+  rpc:
+    authToken: 'BASE_RPC_AUTH_TOKEN'
 ethereum:
   rpc:
     authToken: 'ETHEREUM_RPC_AUTH_TOKEN'

diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -89,7 +89,7 @@
     "@rosen-bridge/discord-notification": "^1.0.0",
     "@rosen-bridge/ergo-observation-extractor": "^1.0.4",
     "@rosen-bridge/ergo-scanner": "^1.0.3",
-    "@rosen-bridge/evm-observation-extractor": "^6.0.4",
+    "@rosen-bridge/evm-observation-extractor": "^6.1.0",
     "@rosen-bridge/evm-scanner": "^1.0.3",
     "@rosen-bridge/extended-typeorm": "1.0.1",
     "@rosen-bridge/firo-observation-extractor": "^0.1.2",

diff --git a/src/config/config.ts b/src/config/config.ts
@@ -17,6 +17,7 @@ const supportedNetworks: Array<NetworkType> = [
   Constants.BITCOIN_CHAIN_NAME,
   Constants.BITCOIN_RUNES_CHAIN_NAME,
   Constants.DOGE_CHAIN_NAME,
+  Constants.BASE_CHAIN_NAME,
   Constants.ETHEREUM_CHAIN_NAME,
   Constants.BINANCE_CHAIN_NAME,
   Constants.FIRO_CHAIN_NAME,
@@ -27,6 +28,7 @@ interface ConfigType {
   cardano: CardanoConfig;
   bitcoin: BitcoinConfig;
   bitcoinRunes: BitcoinRunesConfig;
+  base: BaseConfig;
   ethereum: EthereumConfig;
   binance: BinanceConfig;
   firo: FiroConfig;
@@ -235,6 +237,7 @@ class Config {
       [Constants.BITCOIN_CHAIN_NAME]: Constants.BITCOIN_BLOCK_TIME,
       [Constants.BITCOIN_RUNES_CHAIN_NAME]: Constants.BITCOIN_BLOCK_TIME,
       [Constants.CARDANO_CHAIN_NAME]: Constants.CARDANO_BLOCK_TIME,
+      [Constants.BASE_CHAIN_NAME]: Constants.BASE_BLOCK_TIME,
       [Constants.BINANCE_CHAIN_NAME]: Constants.BINANCE_BLOCK_TIME,
       [Constants.ETHEREUM_CHAIN_NAME]: Constants.ETHEREUM_BLOCK_TIME,
       [Constants.DOGE_CHAIN_NAME]: Constants.DOGE_BLOCK_TIME,
@@ -579,6 +582,35 @@ class EthereumConfig {
   }
 }
 
+class BaseConfig {
+  type: string;
+  initialHeight: number;
+  interval: number;
+  rpc?: {
+    url: string;
+    timeout: number;
+    authToken?: string;
+  };
+
+  constructor(network: string) {
+    this.type = config.get<string>('base.type');
+    if (network === Constants.BASE_CHAIN_NAME) {
+      this.initialHeight = getRequiredNumber('base.initial.height');
+      this.interval = getRequiredNumber('base.interval');
+      if (this.type == Constants.EVM_RPC_TYPE) {
+        const url = getRequiredString('base.rpc.url');
+        const timeout = getRequiredNumber('base.rpc.timeout');
+        const authToken = getOptionalString('base.rpc.authToken', undefined);
+        this.rpc = { url, timeout, authToken };
+      } else {
+        throw new Error(
+          `Improperly configured. base configuration type is invalid available choices are '${Constants.EVM_RPC_TYPE}'`
+        );
+      }
+    }
+  }
+}
+
 class BinanceConfig {
   type: string;
   initialHeight: number;
@@ -747,6 +779,7 @@ const getConfig = (): ConfigType => {
     const bitcoin = new BitcoinConfig(general.networkWatcher);
     const bitcoinRunes = new BitcoinRunesConfig(general.networkWatcher);
     const doge = new DogeConfig(general.networkWatcher);
+    const base = new BaseConfig(general.networkWatcher);
     const ethereum = new EthereumConfig(general.networkWatcher);
     const binance = new BinanceConfig(general.networkWatcher);
     const firo = new FiroConfig(general.networkWatcher);
@@ -762,6 +795,7 @@ const getConfig = (): ConfigType => {
       bitcoin,
       bitcoinRunes,
       doge,
+      base,
       ethereum,
       binance,
       firo,
@@ -783,6 +817,7 @@ export {
   CardanoConfig,
   BitcoinConfig,
   BitcoinRunesConfig,
+  BaseConfig,
   EthereumConfig,
   BinanceConfig,
   FiroConfig,

diff --git a/src/config/constants.ts b/src/config/constants.ts
@@ -16,6 +16,7 @@ export const CARDANO_CHAIN_NAME = 'cardano';
 export const BITCOIN_CHAIN_NAME = 'bitcoin';
 export const BITCOIN_RUNES_CHAIN_NAME = 'bitcoin-runes';
 export const DOGE_CHAIN_NAME = 'doge';
+export const BASE_CHAIN_NAME = 'base';
 export const ETHEREUM_CHAIN_NAME = 'ethereum';
 export const BINANCE_CHAIN_NAME = 'binance';
 export const FIRO_CHAIN_NAME = 'firo';
@@ -32,6 +33,7 @@ export const BINANCE_BLOCK_TIME = 0.75;
 export const BITCOIN_BLOCK_TIME = 600;
 export const CARDANO_BLOCK_TIME = 20;
 export const ERGO_BLOCK_TIME = 120;
+export const BASE_BLOCK_TIME = 2;
 export const ETHEREUM_BLOCK_TIME = 12;
 export const DOGE_BLOCK_TIME = 60;
 export const FIRO_BLOCK_TIME = 150;

diff --git a/src/jobs/initScanner.ts b/src/jobs/initScanner.ts
@@ -13,6 +13,7 @@ const {
   bitcoin: bitcoinConfig,
   bitcoinRunes: bitcoinRunesConfig,
   doge: dogeConfig,
+  base: baseConfig,
   ethereum: ethereumConfig,
   binance: binanceConfig,
   firo: firoConfig,
@@ -75,6 +76,12 @@ export const scannerInit = () => {
         scanner.getObservationScanner() as EvmRpcScanner
       ).then(() => null);
       break;
+    case Constants.BASE_CHAIN_NAME:
+      scanningJob(
+        baseConfig.interval,
+        scanner.getObservationScanner() as EvmRpcScanner
+      ).then(() => null);
+      break;
     case Constants.BINANCE_CHAIN_NAME:
       scanningJob(
         binanceConfig.interval,

diff --git a/src/types/config.ts b/src/types/config.ts
@@ -6,6 +6,7 @@ type NetworkType =
   | typeof Constants.BITCOIN_CHAIN_NAME
   | typeof Constants.BITCOIN_RUNES_CHAIN_NAME
   | typeof Constants.DOGE_CHAIN_NAME
+  | typeof Constants.BASE_CHAIN_NAME
   | typeof Constants.ETHEREUM_CHAIN_NAME
   | typeof Constants.BINANCE_CHAIN_NAME
   | typeof Constants.FIRO_CHAIN_NAME;

diff --git a/src/utils/healthCheck.ts b/src/utils/healthCheck.ts
@@ -24,6 +24,8 @@ import { LogLevelHealthCheck } from '@rosen-bridge/log-level-check';
 import { Transaction } from '../api/Transaction';
 import { getConfig } from '../config/config';
 import {
+  BASE_BLOCK_TIME,
+  BASE_CHAIN_NAME,
   BINANCE_BLOCK_TIME,
   BINANCE_CHAIN_NAME,
   BITCOIN_BLOCK_TIME,
@@ -238,6 +240,11 @@ class HealthCheckSingleton {
           chainBlockTime = DOGE_BLOCK_TIME;
           updateInterval = getConfig().doge.interval;
           break;
+        case BASE_CHAIN_NAME:
+          chainName = BASE_CHAIN_NAME;
+          chainBlockTime = BASE_BLOCK_TIME;
+          updateInterval = getConfig().base.interval;
+          break;
         case ETHEREUM_CHAIN_NAME:
           chainName = ETHEREUM_CHAIN_NAME;
           chainBlockTime = ETHEREUM_BLOCK_TIME;

diff --git a/src/utils/networkConnectorManagers.ts b/src/utils/networkConnectorManagers.ts
@@ -243,7 +243,7 @@ export const createCardanoBlockfrostNetworkConnectorManager = () => {
 
 /**
  * Creates and configures a NetworkConnectorManager instance for EVM-based scanners (Ethereum/Binance)
- * @param chainName - The name of the chain to create a connector for (ethereum/binance)
+ * @param chainName - The name of the chain to create a connector for (base/ethereum/binance)
  */
 export const createEvmNetworkConnectorManager = (chainName: string) => {
   const networkConnectorManager =
@@ -252,7 +252,15 @@ export const createEvmNetworkConnectorManager = (chainName: string) => {
       evmLogger
     );
 
-  if (chainName === 'ethereum' && config.ethereum.rpc) {
+  if (chainName === 'base' && config.base.rpc) {
+    networkConnectorManager.addConnector(
+      new EvmRpcNetwork(
+        config.base.rpc.url,
+        config.base.rpc.timeout * 1000,
+        config.base.rpc.authToken || undefined
+      )
+    );
+  } else if (chainName === 'ethereum' && config.ethereum.rpc) {
     networkConnectorManager.addConnector(
       new EvmRpcNetwork(
         config.ethereum.rpc.url,

diff --git a/src/utils/scanner.ts b/src/utils/scanner.ts
@@ -40,6 +40,7 @@ import {
 } from '@rosen-bridge/bitcoin-runes-observation-extractor';
 
 import {
+  BaseRpcObservationExtractor,
   BinanceRpcObservationExtractor,
   EthereumRpcObservationExtractor,
 } from '@rosen-bridge/evm-observation-extractor';
@@ -50,6 +51,7 @@ import { dataSource } from '../../config/dataSource';
 import {
   BinanceConfig,
   BitcoinConfig,
+  BaseConfig,
   CardanoConfig,
   Config,
   EthereumConfig,
@@ -126,6 +128,7 @@ class CreateScanner {
         bitcoin: bitcoinConfig,
         bitcoinRunes: bitcoinRunesConfig,
         doge: dogeConfig,
+        base: baseConfig,
         ethereum: ethereumConfig,
         binance: binanceConfig,
         firo: firoConfig,
@@ -162,6 +165,13 @@ class CreateScanner {
             config.observationStoreRawData
           );
           break;
+        case Constants.BASE_CHAIN_NAME:
+          await CreateScanner.instance.createBaseScanner(
+            baseConfig,
+            rosenConfig,
+            config.observationStoreRawData
+          );
+          break;
         case Constants.BINANCE_CHAIN_NAME:
           await CreateScanner.instance.createBinanceScanner(
             binanceConfig,
@@ -557,6 +567,32 @@ class CreateScanner {
     }
   };
 
+  private createBaseScanner = async (
+    baseConfig: BaseConfig,
+    rosenConfig: RosenConfig,
+    observationStoreRawData: boolean
+  ) => {
+    if (!this.observationScanner) {
+      if (baseConfig.rpc) {
+        this.observationScanner = new EvmRpcScanner(Constants.BASE_CHAIN_NAME, {
+          dataSource,
+          initialHeight: baseConfig.initialHeight,
+          network: createEvmNetworkConnectorManager(Constants.BASE_CHAIN_NAME),
+          logger: loggers.observationScannerLogger,
+        });
+
+        const observationExtractor = new BaseRpcObservationExtractor(
+          rosenConfig.lockAddress,
+          dataSource,
+          TokensConfig.getInstance().getTokenMap(),
+          loggers.observationExtractorLogger,
+          observationStoreRawData
+        );
+        this.observationScanner.registerExtractor(observationExtractor);
+      }
+    }
+  };
+
   private createBinanceScanner = async (
     binanceConfig: BinanceConfig,
     rosenConfig: RosenConfig,