Add relayer fee configuration to relayer (#571)

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace.package]
-version = "0.5.9-dev"
+version = "0.5.10-dev"
 authors = ["Webb Developers <drew@webb.tools>"]
 license = "Apache-2.0"
 documentation = "https://docs.rs/webb-relayer"

config/README.md

@@ -33,6 +33,9 @@ following section we will describe the different configuration entries and how t
   - [beneficiary](#beneficiary)
   - [tx-queue](#tx-queue)
     - [max-sleep-interval](#max-sleep-interval)
+  - [relayer-fee-config](#relayer-fee-config)
+    - [relayer-profit-percent](#relayer-profit-percent)
+    - [max-refund-amount](#max-refund-amount)
   - [contracts](#contracts)
     - [contract](#contract)
     - [address](#address)
@@ -469,6 +472,29 @@ Example:
 tx-queue = { max-sleep-interval = 5000, polling-interval = 12000 }
 ```
 
+#### Relayer fee Config
+This configuration is used to configure profit percentage margin for relayer and set maximum amount relayer can refund to user while withdrawing.
+
+##### relayer-profit-percent
+The percentage of profit relayer will get from the transaction fee.
+
+- Type: `number`
+- Required: `false`
+- Default: `5`
+
+##### max-refund-amount
+The maximum amount of native token that relayer will refund to the user in USD.
+
+- Type: `number`
+- Required: `false`
+- Default: `5`
+
+Example:
+
+```toml
+relayer-fee-config = { relayer-profit-percent= 5, max-refund-amount = 5 }
+```
+
 #### Contracts
 
 The contracts section is used to configure the contracts that the relayer will use to interact with

config/development/evm-blanknet/athena.toml

@@ -28,6 +28,10 @@ chain-id = 5002
 private-key = "$ATHENA_PRIVATE_KEY"
 
 tx-queue = { max-sleep-interval = 1500, polling-interval = 12000 }
+# The relayer fee configuration for this chain.
+# relayer-profit-percentis percentage of profit relayer will get from the transaction fee.
+# max-refund-amount is the maximum amount of native token that relayer will refund to the user( in usd)
+relayer-fee-config = { relayer-profit-percent= 5, max-refund-amount = 5 }
 # Value to indicate that the relayer should enable services for this chain
 enabled = true
 

config/development/evm-blanknet/demeter.toml

@@ -27,6 +27,10 @@ chain-id = 5003
 #    then we should process it as a mnemonic string: 'word two three four ...'
 private-key = "$DEMETER_PRIVATE_KEY"
 tx-queue = { max-sleep-interval = 1500, polling-interval = 12000 }
+# The relayer fee configuration for this chain.
+# relayer-profit-percentis percentage of profit relayer will get from the transaction fee.
+# max-refund-amount is the maximum amount of native token that relayer will refund to the user( in usd)
+relayer-fee-config = { relayer-profit-percent = 5, max-refund-amount = 5 }
 # Value to indicate that the relayer should enable services for this chain
 enabled = true
 

config/development/evm-blanknet/hermes.toml

@@ -27,6 +27,10 @@ chain-id = 5001
 #    then we should process it as a mnemonic string: 'word two three four ...'
 private-key = "$HERMES_PRIVATE_KEY"
 tx-queue = { max-sleep-interval = 1500, polling-interval = 12000 }
+# The relayer fee configuration for this chain.
+# relayer-profit-percentis percentage of profit relayer will get from the transaction fee.
+# max-refund-amount is the maximum amount of native token that relayer will refund to the user( in usd)
+relayer-fee-config = { relayer-profit-percent= 5, max-refund-amount = 5 }
 # Value to indicate that the relayer should enable services for this chain
 enabled = true
 

config/development/evm-local-tangle/athena.json

@@ -10,6 +10,10 @@
         "max-sleep-interval": 1500,
         "polling-interval": 12000
         },
+      "relayer-fee-config" : {
+        "relayer-profit-percent": 5,
+        "max-refund-amount": 5
+      },
       "enabled": true,
       "contracts": [
         {

config/development/evm-local-tangle/demeter.json

@@ -10,6 +10,10 @@
         "max-sleep-interval": 1500,
         "polling-interval": 12000
       },
+      "relayer-fee-config" : {
+        "relayer-profit-percent": 5,
+        "max-refund-amount": 5
+      },
       "enabled": true,
       "contracts": [
         {

config/development/evm-local-tangle/hermes.json

@@ -10,6 +10,10 @@
         "max-sleep-interval": 1500,
         "polling-interval": 12000
       },
+      "relayer-fee-config" : {
+        "relayer-profit-percent": 5,
+        "max-refund-amount": 5
+      },
       "enabled": true,
       "contracts": [
         {

crates/relayer-config/src/evm/mod.rs

@@ -71,11 +71,33 @@ pub struct EvmChainConfig {
     /// TxQueue configuration
     #[serde(skip_serializing, default)]
     pub tx_queue: TxQueueConfig,
+    /// Relayer fee configuration
+    #[serde(default)]
+    pub relayer_fee_config: RelayerFeeConfig,
     /// Block poller/listening configuration
     #[serde(skip_serializing, default)]
     pub block_poller: Option<BlockPollerConfig>,
 }
 
+/// Transaction withdraw fee configuration.
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all(serialize = "camelCase", deserialize = "kebab-case"))]
+pub struct RelayerFeeConfig {
+    /// Relayer profit percent per transaction fee for relaying
+    pub relayer_profit_percent: f64,
+    /// Maximum refund amount per transaction relaying
+    pub max_refund_amount: f64,
+}
+
+impl Default for RelayerFeeConfig {
+    fn default() -> Self {
+        Self {
+            relayer_profit_percent: 5.,
+            max_refund_amount: 5.,
+        }
+    }
+}
+
 /// configuration for adding http endpoints.
 #[derive(Debug, Clone, Deserialize, Serialize)]
 #[serde(untagged)]