From 856a3ffd3331c90d9730dedec635ee39bf9bd97b Mon Sep 17 00:00:00 2001
From: Nathan Flurry <developer@nathanflurry.com>
Date: Mon, 3 Nov 2025 11:36:39 -0800
Subject: [PATCH] fix(runner): close active requests after onActorStop has
 finished running

---
 engine/sdks/typescript/runner/src/mod.ts    | 10 ++++++++--
 engine/sdks/typescript/runner/src/tunnel.ts |  9 +++++++--
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/engine/sdks/typescript/runner/src/mod.ts b/engine/sdks/typescript/runner/src/mod.ts
index 9a8180a85a..9dfa78fe20 100644
--- a/engine/sdks/typescript/runner/src/mod.ts
+++ b/engine/sdks/typescript/runner/src/mod.ts
@@ -164,12 +164,19 @@ export class Runner {
 		if (!actor) return;
 
 		// If onActorStop times out, Pegboard will handle this timeout with ACTOR_STOP_THRESHOLD_DURATION_MS
+		//
+		// If we receive a request while onActorStop is running, a Service
+		// Unavailable error will be returned to Guard and the request will be
+		// retried
 		try {
 			await this.#config.onActorStop(actorId, actor.generation);
 		} catch (err) {
 			console.error(`Error in onActorStop for actor ${actorId}:`, err);
 		}
 
+		// Close requests after onActorStop so you can send messages over the tunnel
+		this.#tunnel?.closeActiveRequests(actor);
+
 		this.#sendActorStateUpdate(actorId, actor.generation, "stopped");
 	}
 
@@ -217,6 +224,7 @@ export class Runner {
 		);
 	}
 
+	// IMPORTANT: Make sure to call stopActiveRequests if calling #removeActor
 	#removeActor(
 		actorId: string,
 		generation?: number,
@@ -242,8 +250,6 @@ export class Runner {
 
 		this.#actors.delete(actorId);
 
-		// Unregister actor from tunnel
-		this.#tunnel?.unregisterActor(actor);
 
 		return actor;
 	}
diff --git a/engine/sdks/typescript/runner/src/tunnel.ts b/engine/sdks/typescript/runner/src/tunnel.ts
index d617a795fc..5c93445392 100644
--- a/engine/sdks/typescript/runner/src/tunnel.ts
+++ b/engine/sdks/typescript/runner/src/tunnel.ts
@@ -183,7 +183,7 @@ export class Tunnel {
 		}
 	}
 
-	unregisterActor(actor: ActorInstance) {
+	closeActiveRequests(actor: ActorInstance) {
 		const actorId = actor.actorId;
 
 		// Terminate all requests for this actor
@@ -469,7 +469,12 @@ export class Tunnel {
 				msg: "ignoring websocket for unknown actor",
 				actorId: open.actorId,
 			});
-			// Send close immediately
+
+			// NOTE: Closing a WebSocket before open is equivalent to a Service
+			// Unavailable error and will cause Guard to retry the request
+			//
+			// See
+			// https://github.com/rivet-dev/rivet/blob/222dae87e3efccaffa2b503de40ecf8afd4e31eb/engine/packages/pegboard-gateway/src/lib.rs#L238
 			this.#sendMessage(requestId, {
 				tag: "ToServerWebSocketClose",
 				val: {