feat(bindings): add epoch example (#167)

* feat(bindings): add epoch example

* plural

---------

Co-authored-by: Thibault Martinez <[email protected]>

Author: Thoralf-M

.github/workflows/bindings.yml

@@ -26,7 +26,7 @@ jobs:
         run: make go
       - name: Checks for uncommitted changes
         run: git diff --exit-code
-      - name: Run the example
+      - name: Run the examples
         run: make go-examples
   kotlin:
     runs-on: ubuntu-latest
@@ -42,7 +42,7 @@ jobs:
           curl -s "https://get.sdkman.io" | bash
           source "$HOME/.sdkman/bin/sdkman-init.sh"
           sdk install gradle
-      - name: Run the example
+      - name: Run the examples
         run: make kotlin-examples
   python:
     runs-on: ubuntu-latest
@@ -53,5 +53,5 @@ jobs:
         run: make python
       - name: Checks for uncommitted changes
         run: git diff --exit-code
-      - name: Run the example
+      - name: Run the examples
         run: make python-examples

bindings/go/examples/epoch.go

@@ -0,0 +1,49 @@
+// Copyright (c) 2025 IOTA Stiftung
+// SPDX-License-Identifier: Apache-2.0
+
+package main
+
+import (
+	"fmt"
+	"log"
+
+	sdk "bindings/iota_sdk_ffi"
+)
+
+func isNilError(err error) bool {
+	if sdkErr, ok := err.(*sdk.SdkFfiError); ok {
+		return sdkErr == nil
+	}
+	return false
+}
+
+func main() {
+	client := sdk.GraphQlClientNewDevnet()
+
+	// Get current epoch
+	currentEpoch, err := client.Epoch(nil)
+	if !isNilError(err) {
+		log.Fatalf("Failed to get current epoch: %v", err)
+	}
+	if currentEpoch == nil {
+		log.Fatal("Current epoch is nil")
+	}
+
+	fmt.Printf("Current epoch: %d\n", currentEpoch.EpochId)
+	fmt.Printf("Current epoch start time: %d\n", currentEpoch.StartTimestamp)
+
+	// Get previous epoch
+	previousEpochId := currentEpoch.EpochId - 1
+	previousEpoch, err := client.Epoch(&previousEpochId)
+	if !isNilError(err) {
+		log.Fatalf("Failed to get previous epoch: %v", err)
+	}
+	if previousEpoch == nil {
+		log.Fatal("Previous epoch is nil")
+	}
+
+	fmt.Printf("Previous epoch: %d\n", previousEpoch.EpochId)
+	if previousEpoch.TotalStakeRewards != nil {
+		fmt.Printf("Previous epoch stake rewards: %s\n", *previousEpoch.TotalStakeRewards)
+	}
+}

bindings/kotlin/examples/Epoch.kt

@@ -0,0 +1,36 @@
+// Copyright (c) 2025 IOTA Stiftung
+// SPDX-License-Identifier: Apache-2.0
+
+import iota_sdk.GraphQlClient
+import kotlinx.coroutines.runBlocking
+
+fun main() = runBlocking {
+    try {
+        val client = GraphQlClient.newDevnet()
+
+        // Get current epoch
+        val currentEpoch = client.epoch(null)
+        if (currentEpoch == null) {
+            println("Current epoch is null")
+            return@runBlocking
+        }
+
+        println("Current epoch: ${currentEpoch.epochId}")
+        println("Current epoch start time: ${currentEpoch.startTimestamp}")
+
+        // Get previous epoch
+        val previousEpochId = currentEpoch.epochId - 1u
+        val previousEpoch = client.epoch(previousEpochId)
+        if (previousEpoch == null) {
+            println("Previous epoch is null")
+            return@runBlocking
+        }
+
+        println("Previous epoch: ${previousEpoch.epochId}")
+        previousEpoch.totalStakeRewards?.let { rewards ->
+            println("Previous epoch stake rewards: $rewards")
+        }
+    } catch (e: Exception) {
+        e.printStackTrace()
+    }
+}

bindings/python/examples/epoch.py

@@ -0,0 +1,37 @@
+# Copyright (c) 2025 IOTA Stiftung
+# SPDX-License-Identifier: Apache-2.0
+
+import asyncio
+from lib.iota_sdk_ffi import GraphQlClient
+
+
+async def main():
+    try:
+        client = GraphQlClient.new_devnet()
+
+        # Get current epoch
+        current_epoch = await client.epoch(None)
+        if current_epoch is None:
+            print("Current epoch is None")
+            return
+
+        print(f"Current epoch: {current_epoch.epoch_id}")
+        print(f"Current epoch start time: {current_epoch.start_timestamp}")
+
+        # Get previous epoch
+        previous_epoch_id = current_epoch.epoch_id - 1
+        previous_epoch = await client.epoch(previous_epoch_id)
+        if previous_epoch is None:
+            print("Previous epoch is None")
+            return
+
+        print(f"Previous epoch: {previous_epoch.epoch_id}")
+        if previous_epoch.total_stake_rewards is not None:
+            print(f"Previous epoch stake rewards: {previous_epoch.total_stake_rewards}")
+
+    except Exception as e:
+        print(f"Error: {e}")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())