diff --git a/src/main/kotlin/dev/usbharu/hideout/exception/ap/JsonParseException.kt b/src/main/kotlin/dev/usbharu/hideout/exception/ap/JsonParseException.kt
new file mode 100644
index 00000000..61208029
--- /dev/null
+++ b/src/main/kotlin/dev/usbharu/hideout/exception/ap/JsonParseException.kt
@@ -0,0 +1,8 @@
+package dev.usbharu.hideout.exception.ap
+
+class JsonParseException : IllegalArgumentException {
+    constructor() : super()
+    constructor(s: String?) : super(s)
+    constructor(message: String?, cause: Throwable?) : super(message, cause)
+    constructor(cause: Throwable?) : super(cause)
+}
diff --git a/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubService.kt b/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubService.kt
index 070046a3..55d3eec4 100644
--- a/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubService.kt
+++ b/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubService.kt
@@ -1,7 +1,7 @@
 package dev.usbharu.hideout.service.activitypub
 
 interface ActivityPubService {
-    fun parseActivity(json:String): ActivityType
+    fun parseActivity(json:String): List<ActivityType>
 
     fun processActivity(json:String, type: ActivityType)
 }
diff --git a/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubServiceImpl.kt b/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubServiceImpl.kt
new file mode 100644
index 00000000..6e407bb3
--- /dev/null
+++ b/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubServiceImpl.kt
@@ -0,0 +1,55 @@
+package dev.usbharu.hideout.service.activitypub
+
+import com.fasterxml.jackson.databind.JsonNode
+import dev.usbharu.hideout.config.Config
+import dev.usbharu.hideout.exception.ap.JsonParseException
+
+class ActivityPubServiceImpl : ActivityPubService {
+    override fun parseActivity(json: String): List<ActivityType> {
+        val readTree = Config.configData.objectMapper.readTree(json)
+        if (readTree.isObject.not()) {
+            throw JsonParseException("Json is not object.")
+        }
+        val type = readTree["type"]
+        if (type.isArray) {
+            return type.mapNotNull { jsonNode: JsonNode ->
+                ActivityType.values().filter { it.name.equals(jsonNode.toPrettyString(), true) }
+            }.flatten()
+        }
+        return ActivityType.values().filter { it.name.equals(type.toPrettyString(), true) }
+    }
+
+    override fun processActivity(json: String, type: ActivityType) {
+        when (type) {
+            ActivityType.Accept -> TODO()
+            ActivityType.Add -> TODO()
+            ActivityType.Announce -> TODO()
+            ActivityType.Arrive -> TODO()
+            ActivityType.Block -> TODO()
+            ActivityType.Create -> TODO()
+            ActivityType.Delete -> TODO()
+            ActivityType.Dislike -> TODO()
+            ActivityType.Flag -> TODO()
+            ActivityType.Follow -> TODO()
+            ActivityType.Ignore -> TODO()
+            ActivityType.Invite -> TODO()
+            ActivityType.Join -> TODO()
+            ActivityType.Leave -> TODO()
+            ActivityType.Like -> TODO()
+            ActivityType.Listen -> TODO()
+            ActivityType.Move -> TODO()
+            ActivityType.Offer -> TODO()
+            ActivityType.Question -> TODO()
+            ActivityType.Reject -> TODO()
+            ActivityType.Read -> TODO()
+            ActivityType.Remove -> TODO()
+            ActivityType.TentativeReject -> TODO()
+            ActivityType.TentativeAccept -> TODO()
+            ActivityType.Travel -> TODO()
+            ActivityType.Undo -> TODO()
+            ActivityType.Update -> TODO()
+            ActivityType.View -> TODO()
+            ActivityType.Other -> TODO()
+        }
+    }
+}