diff --git a/README.md b/README.md
index c23b04b..ccc458b 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,16 @@ The plugin requires the gRPC target to be provided via environment variable:
 export PLAYER_PRESENCE_GRPC_TARGET="dns:///service-player.api.svc.cluster.local:9000"
 ```
 
+Optional heartbeat configuration:
+
+```bash
+export PLAYER_PRESENCE_HEARTBEAT_SECONDS="30"
+export PLAYER_SESSIONS_TTL="90s"
+```
+
+`PLAYER_PRESENCE_HEARTBEAT_SECONDS` is automatically clamped to a safe value based on
+`PLAYER_SESSIONS_TTL` (`max = ttl / 3`) to reduce false stale-session cleanup.
+
 Messages are configured in `velocity/src/main/resources/messages.yml` (copied to the plugin data
 directory on first run).
 
diff --git a/common/build.gradle.kts b/common/build.gradle.kts
index cce2133..1bc3fdd 100644
--- a/common/build.gradle.kts
+++ b/common/build.gradle.kts
@@ -10,4 +10,4 @@ repositories {
     }
 }
 
-dependencies { protobuf("gg.grounds:library-grpc-contracts-player:0.1.0") }
+dependencies { protobuf("gg.grounds:library-grpc-contracts-player:feat-player-heartbeat-SNAPSHOT") }
diff --git a/common/src/main/kotlin/gg/grounds/player/presence/GrpcPlayerPresenceClient.kt b/common/src/main/kotlin/gg/grounds/player/presence/GrpcPlayerPresenceClient.kt
index 5a34d1e..680006f 100644
--- a/common/src/main/kotlin/gg/grounds/player/presence/GrpcPlayerPresenceClient.kt
+++ b/common/src/main/kotlin/gg/grounds/player/presence/GrpcPlayerPresenceClient.kt
@@ -1,5 +1,7 @@
 package gg.grounds.player.presence
 
+import gg.grounds.grpc.player.PlayerHeartbeatBatchReply
+import gg.grounds.grpc.player.PlayerHeartbeatBatchRequest
 import gg.grounds.grpc.player.PlayerLoginRequest
 import gg.grounds.grpc.player.PlayerLogoutReply
 import gg.grounds.grpc.player.PlayerLogoutRequest
@@ -49,6 +51,22 @@ private constructor(
         }
     }
 
+    fun heartbeatBatch(playerIds: Collection<UUID>): PlayerHeartbeatBatchReply {
+        return try {
+            val request =
+                PlayerHeartbeatBatchRequest.newBuilder()
+                    .addAllPlayerIds(playerIds.map { it.toString() })
+                    .build()
+            stub
+                .withDeadlineAfter(DEFAULT_TIMEOUT_MS, TimeUnit.MILLISECONDS)
+                .playerHeartbeatBatch(request)
+        } catch (e: StatusRuntimeException) {
+            errorHeartbeatBatchReply(e.status.toString())
+        } catch (e: RuntimeException) {
+            errorHeartbeatBatchReply(e.message ?: e::class.java.name)
+        }
+    }
+
     override fun close() {
         channel.shutdown()
         try {
@@ -74,6 +92,14 @@ private constructor(
         private fun errorLogoutReply(message: String): PlayerLogoutReply =
             PlayerLogoutReply.newBuilder().setRemoved(false).setMessage(message).build()
 
+        private fun errorHeartbeatBatchReply(message: String): PlayerHeartbeatBatchReply =
+            PlayerHeartbeatBatchReply.newBuilder()
+                .setUpdated(0)
+                .setMissing(0)
+                .setSuccess(false)
+                .setMessage(message)
+                .build()
+
         private fun isServiceUnavailable(status: Status.Code): Boolean =
             status == Status.Code.UNAVAILABLE || status == Status.Code.DEADLINE_EXCEEDED
 
diff --git a/velocity/build.gradle.kts b/velocity/build.gradle.kts
index e835e17..9da7e1e 100644
--- a/velocity/build.gradle.kts
+++ b/velocity/build.gradle.kts
@@ -5,4 +5,8 @@ dependencies {
     implementation("tools.jackson.dataformat:jackson-dataformat-yaml:3.0.3")
     implementation("tools.jackson.module:jackson-module-kotlin:3.0.3")
     implementation("io.grpc:grpc-netty-shaded:1.78.0")
+
+    testImplementation("org.junit.jupiter:junit-jupiter-api:5.13.4")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.13.4")
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher:1.13.4")
 }
diff --git a/velocity/src/main/kotlin/gg/grounds/GroundsPluginPlayer.kt b/velocity/src/main/kotlin/gg/grounds/GroundsPluginPlayer.kt
index e5f3bab..c56e123 100644
--- a/velocity/src/main/kotlin/gg/grounds/GroundsPluginPlayer.kt
+++ b/velocity/src/main/kotlin/gg/grounds/GroundsPluginPlayer.kt
@@ -9,6 +9,7 @@ import com.velocitypowered.api.plugin.annotation.DataDirectory
 import com.velocitypowered.api.proxy.ProxyServer
 import gg.grounds.config.MessagesConfigLoader
 import gg.grounds.listener.PlayerConnectionListener
+import gg.grounds.presence.PlayerHeartbeatScheduler
 import gg.grounds.presence.PlayerPresenceService
 import io.grpc.LoadBalancerRegistry
 import io.grpc.NameResolverRegistry
@@ -33,6 +34,8 @@ constructor(
     @param:DataDirectory private val dataDirectory: Path,
 ) {
     private val playerPresenceService = PlayerPresenceService()
+    private val heartbeatScheduler =
+        PlayerHeartbeatScheduler(this, proxy, logger, playerPresenceService)
 
     init {
         logger.info("Initialized plugin (plugin=plugin-player, version={})", BuildInfo.VERSION)
@@ -55,11 +58,13 @@ constructor(
             ),
         )
 
+        heartbeatScheduler.start()
         logger.info("Configured player presence gRPC client (target={})", target)
     }
 
     @Subscribe
     fun onShutdown(event: ProxyShutdownEvent) {
+        heartbeatScheduler.stop()
         playerPresenceService.close()
     }
 
diff --git a/velocity/src/main/kotlin/gg/grounds/presence/PlayerHeartbeatScheduler.kt b/velocity/src/main/kotlin/gg/grounds/presence/PlayerHeartbeatScheduler.kt
new file mode 100644
index 0000000..02f8915
--- /dev/null
+++ b/velocity/src/main/kotlin/gg/grounds/presence/PlayerHeartbeatScheduler.kt
@@ -0,0 +1,131 @@
+package gg.grounds.presence
+
+import com.velocitypowered.api.proxy.ProxyServer
+import com.velocitypowered.api.scheduler.ScheduledTask
+import java.util.concurrent.TimeUnit
+import kotlin.math.max
+import kotlin.math.min
+import org.slf4j.Logger
+
+class PlayerHeartbeatScheduler(
+    private val plugin: Any,
+    private val proxy: ProxyServer,
+    private val logger: Logger,
+    private val presenceService: PlayerPresenceService,
+) {
+    private var heartbeatTask: ScheduledTask? = null
+
+    fun start() {
+        heartbeatTask?.cancel()
+        heartbeatTask = null
+        val intervalResolution =
+            resolveHeartbeatIntervalSeconds(
+                System.getenv(HEARTBEAT_INTERVAL_ENV),
+                System.getenv(SESSION_TTL_ENV),
+            )
+        heartbeatTask =
+            proxy.scheduler
+                .buildTask(plugin, Runnable { sendHeartbeats() })
+                .repeat(intervalResolution.effectiveIntervalSeconds, TimeUnit.SECONDS)
+                .schedule()
+        if (intervalResolution.wasClamped) {
+            logger.warn(
+                "Player heartbeat interval clamped (configuredIntervalSeconds={}, effectiveIntervalSeconds={}, sessionTtlSeconds={}, maxIntervalSeconds={})",
+                intervalResolution.configuredIntervalSeconds,
+                intervalResolution.effectiveIntervalSeconds,
+                intervalResolution.sessionTtlSeconds,
+                intervalResolution.maxIntervalSeconds,
+            )
+        }
+        logger.info(
+            "Configured player presence heartbeat task (intervalSeconds={}, sessionTtlSeconds={})",
+            intervalResolution.effectiveIntervalSeconds,
+            intervalResolution.sessionTtlSeconds,
+        )
+    }
+
+    fun stop() {
+        heartbeatTask?.cancel()
+        heartbeatTask = null
+    }
+
+    private fun sendHeartbeats() {
+        val playerIds = proxy.allPlayers.map { it.uniqueId }
+        if (playerIds.isEmpty()) {
+            return
+        }
+
+        val result = presenceService.heartbeatBatch(playerIds)
+        if (!result.success) {
+            logger.error(
+                "Player session heartbeat batch failed (playerCount={}, updated={}, missing={}, reason={})",
+                playerIds.size,
+                result.updated,
+                result.missing,
+                result.message,
+            )
+        } else if (result.missing > 0) {
+            logger.warn(
+                "Player session heartbeat batch completed with missing sessions (playerCount={}, updated={}, missing={})",
+                playerIds.size,
+                result.updated,
+                result.missing,
+            )
+        } else {
+            logger.debug(
+                "Player session heartbeat batch completed (playerCount={}, updated={}, missing={}, result=success)",
+                playerIds.size,
+                result.updated,
+                result.missing,
+            )
+        }
+    }
+
+    internal data class HeartbeatIntervalResolution(
+        val configuredIntervalSeconds: Long,
+        val effectiveIntervalSeconds: Long,
+        val sessionTtlSeconds: Long,
+        val maxIntervalSeconds: Long,
+        val wasClamped: Boolean,
+    )
+
+    companion object {
+        private const val DEFAULT_HEARTBEAT_INTERVAL_SECONDS = 30L
+        private const val DEFAULT_SESSION_TTL_SECONDS = 90L
+        private const val HEARTBEAT_INTERVAL_ENV = "PLAYER_PRESENCE_HEARTBEAT_SECONDS"
+        private const val SESSION_TTL_ENV = "PLAYER_SESSIONS_TTL"
+
+        internal fun resolveHeartbeatIntervalSeconds(
+            heartbeatIntervalRaw: String?,
+            sessionTtlRaw: String?,
+        ): HeartbeatIntervalResolution {
+            val configuredInterval =
+                heartbeatIntervalRaw?.trim()?.toLongOrNull()?.takeIf { it > 0 }
+                    ?: DEFAULT_HEARTBEAT_INTERVAL_SECONDS
+            val sessionTtlSeconds =
+                parseSessionTtlSeconds(sessionTtlRaw) ?: DEFAULT_SESSION_TTL_SECONDS
+            val maxIntervalSeconds = max(1L, sessionTtlSeconds / 3)
+            val effectiveInterval = min(configuredInterval, maxIntervalSeconds)
+            return HeartbeatIntervalResolution(
+                configuredIntervalSeconds = configuredInterval,
+                effectiveIntervalSeconds = effectiveInterval,
+                sessionTtlSeconds = sessionTtlSeconds,
+                maxIntervalSeconds = maxIntervalSeconds,
+                wasClamped = effectiveInterval != configuredInterval,
+            )
+        }
+
+        private fun parseSessionTtlSeconds(raw: String?): Long? {
+            val value = raw?.trim()?.lowercase() ?: return null
+            if (value.isEmpty()) {
+                return null
+            }
+            return when {
+                value.endsWith("s") -> value.removeSuffix("s").toLongOrNull()
+                value.endsWith("m") -> value.removeSuffix("m").toLongOrNull()?.times(60)
+                value.endsWith("h") -> value.removeSuffix("h").toLongOrNull()?.times(3600)
+                else -> null
+            }?.takeIf { it > 0 }
+        }
+    }
+}
diff --git a/velocity/src/main/kotlin/gg/grounds/presence/PlayerPresenceService.kt b/velocity/src/main/kotlin/gg/grounds/presence/PlayerPresenceService.kt
index ba6fa37..2ccd3c1 100644
--- a/velocity/src/main/kotlin/gg/grounds/presence/PlayerPresenceService.kt
+++ b/velocity/src/main/kotlin/gg/grounds/presence/PlayerPresenceService.kt
@@ -8,6 +8,13 @@ import java.util.UUID
 class PlayerPresenceService : AutoCloseable {
     private lateinit var client: GrpcPlayerPresenceClient
 
+    data class HeartbeatBatchResult(
+        val success: Boolean,
+        val message: String,
+        val updated: Int,
+        val missing: Int,
+    )
+
     fun configure(target: String) {
         close()
         client = GrpcPlayerPresenceClient.create(target)
@@ -29,6 +36,20 @@ class PlayerPresenceService : AutoCloseable {
         }
     }
 
+    fun heartbeatBatch(playerIds: Collection<UUID>): HeartbeatBatchResult {
+        return try {
+            val reply = client.heartbeatBatch(playerIds)
+            HeartbeatBatchResult(reply.success, reply.message, reply.updated, reply.missing)
+        } catch (e: RuntimeException) {
+            HeartbeatBatchResult(
+                success = false,
+                message = e.message ?: e::class.java.name,
+                updated = 0,
+                missing = playerIds.size,
+            )
+        }
+    }
+
     override fun close() {
         if (this::client.isInitialized) {
             client.close()
diff --git a/velocity/src/test/kotlin/gg/grounds/presence/PlayerHeartbeatSchedulerTest.kt b/velocity/src/test/kotlin/gg/grounds/presence/PlayerHeartbeatSchedulerTest.kt
new file mode 100644
index 0000000..ebb0529
--- /dev/null
+++ b/velocity/src/test/kotlin/gg/grounds/presence/PlayerHeartbeatSchedulerTest.kt
@@ -0,0 +1,63 @@
+package gg.grounds.presence
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertFalse
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+
+class PlayerHeartbeatSchedulerTest {
+    @Test
+    fun resolveHeartbeatIntervalUsesDefaultsWhenUnset() {
+        val result = PlayerHeartbeatScheduler.resolveHeartbeatIntervalSeconds(null, null)
+
+        assertEquals(30, result.configuredIntervalSeconds)
+        assertEquals(30, result.effectiveIntervalSeconds)
+        assertEquals(90, result.sessionTtlSeconds)
+        assertEquals(30, result.maxIntervalSeconds)
+        assertFalse(result.wasClamped)
+    }
+
+    @Test
+    fun resolveHeartbeatIntervalClampsWhenAboveSafeMaximum() {
+        val result = PlayerHeartbeatScheduler.resolveHeartbeatIntervalSeconds("60", "90s")
+
+        assertEquals(60, result.configuredIntervalSeconds)
+        assertEquals(30, result.effectiveIntervalSeconds)
+        assertEquals(90, result.sessionTtlSeconds)
+        assertEquals(30, result.maxIntervalSeconds)
+        assertTrue(result.wasClamped)
+    }
+
+    @Test
+    fun resolveHeartbeatIntervalDoesNotClampWhenWithinSafeMaximum() {
+        val result = PlayerHeartbeatScheduler.resolveHeartbeatIntervalSeconds("20", "90s")
+
+        assertEquals(20, result.configuredIntervalSeconds)
+        assertEquals(20, result.effectiveIntervalSeconds)
+        assertEquals(90, result.sessionTtlSeconds)
+        assertEquals(30, result.maxIntervalSeconds)
+        assertFalse(result.wasClamped)
+    }
+
+    @Test
+    fun resolveHeartbeatIntervalParsesMinuteTtl() {
+        val result = PlayerHeartbeatScheduler.resolveHeartbeatIntervalSeconds("90", "6m")
+
+        assertEquals(90, result.configuredIntervalSeconds)
+        assertEquals(90, result.effectiveIntervalSeconds)
+        assertEquals(360, result.sessionTtlSeconds)
+        assertEquals(120, result.maxIntervalSeconds)
+        assertFalse(result.wasClamped)
+    }
+
+    @Test
+    fun resolveHeartbeatIntervalFallsBackForInvalidValues() {
+        val result = PlayerHeartbeatScheduler.resolveHeartbeatIntervalSeconds("-5", "oops")
+
+        assertEquals(30, result.configuredIntervalSeconds)
+        assertEquals(30, result.effectiveIntervalSeconds)
+        assertEquals(90, result.sessionTtlSeconds)
+        assertEquals(30, result.maxIntervalSeconds)
+        assertFalse(result.wasClamped)
+    }
+}