diff --git a/lib/constructs/socket-mode.ts b/lib/constructs/socket-mode.ts
index b765222..470f699 100644
--- a/lib/constructs/socket-mode.ts
+++ b/lib/constructs/socket-mode.ts
@@ -27,6 +27,10 @@ export class SocketModeConstruct extends Construct {
     const cluster = new ecs.Cluster(this, 'Cluster', {
       clusterName: 'seahaven-socket-mode',
       vpc: props.vpc,
+      // Container Insights publishes ECS/ContainerInsights metrics (incl.
+      // RunningTaskCount) needed for the task-count alarm. This adds CloudWatch
+      // metric + log cost — see PR body "NEEDS ADAM SIGN-OFF (cost/config)".
+      containerInsightsV2: ecs.ContainerInsights.ENABLED,
     });
     this.cluster = cluster;
 
diff --git a/lib/seahaven-slack-bot-stack.ts b/lib/seahaven-slack-bot-stack.ts
index 0b1fdbd..40581e4 100644
--- a/lib/seahaven-slack-bot-stack.ts
+++ b/lib/seahaven-slack-bot-stack.ts
@@ -116,9 +116,11 @@ export class SeahavenSlackBotStack extends cdk.Stack {
       httpApi: slackHandler.api,
       ecsService: socketMode.service,
       ecsCluster: socketMode.cluster,
-      // RunningTaskCount alarm requires Container Insights (cost/config change) —
-      // gated off by default; enabled in a separate, sign-off-gated commit.
-      enableRunningTaskAlarm: false,
+      // RunningTaskCount alarm requires Container Insights, enabled on the
+      // socket-mode cluster (see socket-mode.ts). This adds CloudWatch metric +
+      // log cost — flagged in the PR as "NEEDS ADAM SIGN-OFF (cost/config)".
+      // Drop this commit (and the cluster's containerInsightsV2 line) to decline.
+      enableRunningTaskAlarm: true,
     });
 
     // ── Stack outputs ─────────────────────────────────────────────────────────