Add etherscan api configuration

README.md

@@ -145,6 +145,32 @@ webb-relayer -vv -c ./config
 - [`SubstrateConfig`](https://webb-tools.github.io/relayer/webb_relayer/config/struct.SubstrateConfig.html)
 - [`EvmChainConfig`](https://webb-tools.github.io/relayer/webb_relayer/config/struct.EvmChainConfig.html)
 
+#### Relayer Common Configuration
+| Field                      | Description                                                                                | Optionality |
+| -------------------------- | ------------------------------------------------------------------------------------------ | ----------- |
+| `port`                 | Relayer port number | Required    |
+| `features`                  |Enable required features by setting them to `true` . All featured are enabled by default | Optional|
+| `evm-etherscan`              | Etherscan api configuration for chains, required if `private-tx` feature is enabled for relayer.       | Optional    |
+
+- `Features` Configuration
+
+```
+[features]
+governance-relay = true
+data-query = true
+private-tx-relay = true
+```
+- `Evm-etherscan` Configuration
+```
+[evm-etherscan.goerli]
+chain-id = 5
+api-key = "$ETHERSCAN_GOERLI_API_KEY"
+[evm-etherscan.polygon]
+chain-id = 137
+api-key = "$POLYGONSCAN_MAINNET_API_KEY"
+```
+
+
 #### Chain Configuration
 
 | Field           | Description                                                                                                                        | Optionality            |

config/README.md

@@ -12,6 +12,10 @@ following section we will describe the different configuration entries and how t
     - [governance-relay](#governance-relay)
     - [data-query](#data-query)
     - [private-tx-relay](#private-tx-relay)
+  - [evm-etherscan](#evm-etherscan)
+    - [chain-id](#chain-id)
+    - [api-key](#api-key)
+
 - [EVM Chain Configuration](#evm-chain-configuration)
   - [name](#name)
   - [chain-id](#chain-id)
@@ -168,6 +172,24 @@ Example:
 [features]
 private-tx-relay = true
 ```
+#### evm-etherscan
+Etherscan api configuration for chains. This config is required if [private-tx-relay](#private-tx-relay) is enabled.
+example:
+```toml
+[evm-etherscan.goerli]
+chain-id = 5
+api-key = "$ETHERSCAN_GOERLI_API_KEY"
+[evm-etherscan.polygon]
+chain-id = 137
+api-key = "$POLYGONSCAN_MAINNET_API_KEY"
+```
+
+#### api-key
+Etherscan api key, this are used to fetch gas prices from the explorer.
+example:
+```toml
+api-key = $ETHERSCAN_GOERLI_API_KEY
+```
 
 ### EVM Chain Configuration
 

config/development/.env.example

@@ -5,3 +5,4 @@ ATHENA_PRIVATE_KEY=${PRIVATE_KEY}
 DEMETER_PRIVATE_KEY=${PRIVATE_KEY}
 
 GOVERNOR_PRIVATE_KEY=0x0000000000000000000000000000000000000000000000000000000000000001
+ETHERSCAN_API_KEY=YI7KXQGB98XXXXZJ5595E6Q7ZH2PGU32BG7

config/development/evm-blanknet/main.toml

@@ -3,3 +3,7 @@ port = 9955
 [experimental]
 smart-anchor-updates = false
 smart-anchor-updates-retries = 3
+
+[evm-etherscan.mainnet]
+chain-id = 5001
+api-key = "$ETHERSCAN_API_KEY"

config/development/evm-local-tangle/main.toml

@@ -0,0 +1,9 @@
+port = 9955
+
+[experimental]
+smart-anchor-updates = false
+smart-anchor-updates-retries = 3
+
+[evm-etherscan.mainnet]
+chain-id = 5001
+api-key = "$ETHERSCAN_API_KEY"

config/exclusive-strategies/.env.example

@@ -15,5 +15,5 @@ OPTIMISM_TESTNET_WSS_URL=${EXAMPLE_WSS_URL}
 OPTIMISM_TESTNET_PRIVATE_KEY=${EXAMPLE_PRIVATE_KEY}
 
 
-
+ETHERSCAN_API_KEY=YI7KXQGB98XXXXZJ5595E6Q7ZH2PGU32BG7
 MOCKED_BACKEND_KEY=${EXAMPLE_PRIVATE_KEY}

config/exclusive-strategies/private-tx-relaying/main.toml

@@ -5,4 +5,11 @@ port = 9955
 [features]
 governance-relay = false
 data-query = false
-private-tx-relay = true
+private-tx-relay = true
+
+[evm-etherscan.goerli]
+chain-id = 5
+api-key = "$ETHERSCAN_API_KEY"
+[evm-etherscan.sepolia]
+chain-id = 11155111
+api-key = "$ETHERSCAN_API_KEY"

crates/relayer-config/src/lib.rs

@@ -49,6 +49,8 @@ use evm::EvmChainConfig;
 use serde::{Deserialize, Serialize};
 use std::collections::{HashMap, HashSet};
 use substrate::SubstrateConfig;
+use webb::evm::ethers::types::Chain;
+use webb_relayer_types::etherscan_api::EtherscanApiKey;
 
 /// The default port the relayer will listen on. Defaults to 9955.
 const fn default_port() -> u16 {
@@ -80,6 +82,9 @@ pub struct WebbRelayerConfig {
     /// default to 9955
     #[serde(default = "default_port", skip_serializing)]
     pub port: u16,
+    /// Etherscan API key configuration for evm based chains.
+    #[serde(default)]
+    pub evm_etherscan: HashMap<Chain, EtherscanApiConfig>,
     /// EVM based networks and the configuration.
     ///
     /// a map between chain name and its configuration.
@@ -174,6 +179,16 @@ impl Default for FeaturesConfig {
     }
 }
 
+/// Configuration to add etherscan API key
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "kebab-case")]
+pub struct EtherscanApiConfig {
+    /// Chain Id
+    pub chain_id: u32,
+    /// A wrapper type around the `String` to allow reading it from the env.
+    pub api_key: EtherscanApiKey,
+}
+
 /// TxQueueConfig is the configuration for the TxQueue.
 #[derive(Debug, Clone, Deserialize, Serialize)]
 #[serde(rename_all = "kebab-case")]

crates/relayer-context/src/lib.rs

@@ -16,9 +16,9 @@
 //! # Relayer Context Module 🕸️
 //!
 //! A module for managing the context of the relayer.
-use std::convert::TryFrom;
 use std::sync::Arc;
 use std::time::Duration;
+use std::{collections::HashMap, convert::TryFrom};
 
 use tokio::sync::{broadcast, Mutex};
 
@@ -55,8 +55,8 @@ pub struct RelayerContext {
     store: SledStore,
     /// API client for https://www.coingecko.com/
     coin_gecko_client: Arc<CoinGeckoClient>,
-    /// API client for https://etherscan.io/
-    etherscan_client: Client,
+    /// Hashmap of <ChainID, Etherscan Client>
+    etherscan_clients: HashMap<u32, Client>,
 }
 
 impl RelayerContext {
@@ -68,14 +68,20 @@ impl RelayerContext {
         let (notify_shutdown, _) = broadcast::channel(2);
         let metrics = Arc::new(Mutex::new(Metrics::new()));
         let coin_gecko_client = Arc::new(CoinGeckoClient::default());
-        let etherscan_client = Client::new_from_env(Chain::Mainnet).unwrap();
+        let mut etherscan_clients: HashMap<u32, Client> = HashMap::new();
+        for (chain, etherscan_config) in config.evm_etherscan.iter() {
+            let client =
+                Client::new(*chain, etherscan_config.api_key.to_string())
+                    .unwrap();
+            etherscan_clients.insert(etherscan_config.chain_id, client);
+        }
         Self {
             config,
             notify_shutdown,
             metrics,
             store,
             coin_gecko_client,
-            etherscan_client,
+            etherscan_clients,
         }
     }
     /// Returns a broadcast receiver handle for the shutdown signal.
@@ -187,8 +193,17 @@ impl RelayerContext {
     }
 
     /// Returns API client for https://etherscan.io/
-    pub fn etherscan_client(&self) -> &Client {
-        &self.etherscan_client
+    pub fn etherscan_client(
+        &self,
+        chain_id: u32,
+    ) -> webb_relayer_utils::Result<&Client> {
+        let client =
+            self.etherscan_clients.get(&chain_id).ok_or_else(|| {
+                webb_relayer_utils::Error::EtherscanConfigNotFound {
+                    chain_id: chain_id.to_string(),
+                }
+            })?;
+        Ok(client)
     }
 }
 

crates/relayer-types/src/etherscan_api.rs

@@ -0,0 +1,66 @@
+use serde::{Deserialize, Serialize};
+#[derive(Clone, Serialize)]
+pub struct EtherscanApiKey(String);
+
+impl std::fmt::Debug for EtherscanApiKey {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_tuple("EtherscanApiKey").finish()
+    }
+}
+
+impl From<String> for EtherscanApiKey {
+    fn from(api_key: String) -> Self {
+        EtherscanApiKey(api_key)
+    }
+}
+
+impl std::ops::Deref for EtherscanApiKey {
+    type Target = String;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<'de> Deserialize<'de> for EtherscanApiKey {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        struct EtherscanApiKeyVisitor;
+        impl<'de> serde::de::Visitor<'de> for EtherscanApiKeyVisitor {
+            type Value = String;
+
+            fn expecting(
+                &self,
+                formatter: &mut std::fmt::Formatter,
+            ) -> std::fmt::Result {
+                formatter.write_str(
+                    "Etherscan api key or an env var containing a etherscan api key in it",
+                )
+            }
+
+            fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+            where
+                E: serde::de::Error,
+            {
+                if value.starts_with('$') {
+                    // env
+                    let var = value.strip_prefix('$').unwrap_or(value);
+                    tracing::trace!("Reading {} from env", var);
+                    let val = std::env::var(var).map_err(|e| {
+                        serde::de::Error::custom(format!(
+                            "error while loading this env {var}: {e}",
+                        ))
+                    })?;
+                    return Ok(val);
+                }
+                Ok(value.to_string())
+            }
+        }
+
+        let etherscan_api_key =
+            deserializer.deserialize_str(EtherscanApiKeyVisitor)?;
+        Ok(Self(etherscan_api_key))
+    }
+}

crates/relayer-types/src/lib.rs

@@ -1,4 +1,5 @@
 pub mod dynamic_payload;
+pub mod etherscan_api;
 pub mod mnemonic;
 pub mod private_key;
 pub mod rpc_url;

crates/relayer-utils/src/lib.rs

@@ -151,6 +151,12 @@ pub enum Error {
     /// Arkworks Errors.
     #[error("{}", _0)]
     ArkworksError(String),
+    /// Etherscan api configuration not found.
+    #[error("Etherscan api configuration not found for chain : {}", chain_id)]
+    EtherscanConfigNotFound {
+        /// The chain id of the node.
+        chain_id: String,
+    },
     #[error("No bridge registered with DKG for resource id {:?}", _0)]
     BridgeNotRegistered(ResourceId),
 }

crates/tx-relay/src/evm/fees.rs

@@ -134,7 +134,10 @@ async fn generate_fee_info(
     let wrapped_token_price = prices[&wrapped_token.0].usd.unwrap();
 
     // Fetch native gas price estimate from etherscan.io, using "average" value
-    let gas_oracle = ctx.etherscan_client().gas_oracle().await?;
+    let gas_oracle = ctx
+        .etherscan_client(chain_id.underlying_chain_id())?
+        .gas_oracle()
+        .await?;
     let gas_price_gwei = U256::from(gas_oracle.propose_gas_price);
     let gas_price = parse_units(gas_price_gwei, "gwei")?.into();
 

tests/lib/webbRelayer.ts

@@ -31,6 +31,7 @@ import { padHexString } from '../lib/utils.js';
 
 export type CommonConfig = {
   features?: FeaturesConfig;
+  evmEtherscan?: EvmEtherscanConfig;
   port: number;
 };
 
@@ -76,6 +77,9 @@ export class WebbRelayer {
     // Write the folder-wide configuration for this relayer instance
     type WrittenCommonConfig = {
       features?: ConvertToKebabCase<FeaturesConfig>;
+      'evm-etherscan'?: {
+        [key: string]: ConvertToKebabCase<EtherscanApiConfig>;
+      };
       port: number;
     };
     const commonConfigFile: WrittenCommonConfig = {
@@ -84,6 +88,14 @@ export class WebbRelayer {
         'governance-relay': opts.commonConfig.features?.governanceRelay ?? true,
         'private-tx-relay': opts.commonConfig.features?.privateTxRelay ?? true,
       },
+      'evm-etherscan': Object.fromEntries(
+        Object.entries(opts.commonConfig.evmEtherscan ?? {}).map(
+          ([key, { chainId, apiKey }]) => [
+            key,
+            { ...{ 'chain-id': chainId, 'api-key': apiKey } },
+          ]
+        )
+      ),
       port: opts.commonConfig.port,
     };
     const configString = JSON.stringify(commonConfigFile, null, 2);
@@ -590,6 +602,16 @@ export interface FeaturesConfig {
   governanceRelay?: boolean;
   privateTxRelay?: boolean;
 }
+
+export interface EtherscanApiConfig {
+  chainId: number;
+  apiKey: string;
+}
+
+export interface EvmEtherscanConfig {
+  [key: string]: EtherscanApiConfig;
+}
+
 export interface WithdrawConfig {
   withdrawFeePercentage: number;
   withdrawGaslimit: `0x${string}`;