QueueCast
Amazon SQS & SNS for Blueprints and C++

Overview

QueueCast connects Unreal Engine 4.27 and 5.8 to Amazon Simple Queue Service (SQS) and Amazon Simple Notification Service (SNS). Use queues for reports, telemetry, match results and jobs for your backend, listen to a queue for server events, publish notifications to topics and register players' devices for mobile push. Requests run on background worker threads with automatic retries; every result arrives back on the game thread.

• Send Message / Send Message Batch: string attributes, delays, FIFO group and deduplication ids; batches of any size, 10 per request, per-entry results.
• Receive Messages: long polling, visibility timeout, attributes and receive count.
• Listen To Queue: a listener that keeps long-polling until stopped and fires On Message for every message, with optional auto-delete and back-off on errors.
• Delete Message, Delete Message Batch, Change Message Visibility, Get Queue Url (cached), Get Queue Attributes.
• SNS Publish to a topic, a single device (platform endpoint) or a phone number (SMS).
• Register Push Device: Firebase Cloud Messaging / APNs tokens to SNS platform endpoints, kept up to date automatically.
• Subscribe, Unsubscribe, Set Push Endpoint Enabled.
• Amazon Cognito identity pools for guests and signed-in players; static keys and the default AWS chain for development and servers.

Requirements

Installation

1. Install QueueCast from Fab into your engine, or copy the QueueCast folder into your project's Plugins folder.
2. Enable QueueCast in Edit > Plugins and restart the editor.
3. Open Project Settings > Plugins > QueueCast and set Region, Identity Pool Id and, if you like, a Default Queue and Default Topic Arn.
4. C++ only: add PublicDependencyModuleNames.Add("QueueCast"); to your Build.cs.

Setting up AWS

1. In the SQS console create your queues (Standard, or FIFO with a .fifo name for strict ordering). Use a common prefix such as mygame-.
2. For notifications create SNS topics. For mobile push create a platform application (Firebase Cloud Messaging or APNs) and note its ARN.
3. In Amazon Cognito create an identity pool. Enable guest access if players may use queues before signing in, and add your identity providers.
4. Edit the IAM role the pool gives to players so it may call only the actions QueueCast uses, and only on your game's resources. Leave out every statement you do not need:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "SendReports",
      "Effect": "Allow",
      "Action": ["sqs:GetQueueUrl", "sqs:SendMessage", "sqs:GetQueueAttributes"],
      "Resource": "arn:aws:sqs:us-east-1:123456789012:mygame-reports"
    },
    {
      "Sid": "ReadOwnInbox",
      "Effect": "Allow",
      "Action": ["sqs:GetQueueUrl", "sqs:ReceiveMessage", "sqs:DeleteMessage", "sqs:ChangeMessageVisibility"],
      "Resource": "arn:aws:sqs:us-east-1:123456789012:mygame-events"
    },
    {
      "Sid": "PublishToGameTopic",
      "Effect": "Allow",
      "Action": "sns:Publish",
      "Resource": "arn:aws:sns:us-east-1:123456789012:mygame-player-events"
    },
    {
      "Sid": "RegisterPushDevice",
      "Effect": "Allow",
      "Action": "sns:CreatePlatformEndpoint",
      "Resource": "arn:aws:sns:us-east-1:123456789012:app/GCM/MyGame"
    },
    {
      "Sid": "ManageOwnEndpoint",
      "Effect": "Allow",
      "Action": ["sns:GetEndpointAttributes", "sns:SetEndpointAttributes"],
      "Resource": "arn:aws:sns:us-east-1:123456789012:endpoint/GCM/MyGame/*"
    },
    {
      "Sid": "PushTopicSubscribe",
      "Effect": "Allow",
      "Action": "sns:Subscribe",
      "Resource": "arn:aws:sns:us-east-1:123456789012:mygame-news",
      "Condition": { "StringEquals": { "sns:Protocol": "application" } }
    },
    {
      "Sid": "PushTopicUnsubscribe",
      "Effect": "Allow",
      "Action": "sns:Unsubscribe",
      "Resource": "arn:aws:sns:us-east-1:123456789012:mygame-news"
    }
  ]
}

Batch nodes need the same actions as their single versions (sqs:SendMessage, sqs:DeleteMessage). sqs:GetQueueUrl is not needed when you pass queue URLs or set Queue Url Prefix. Queues and topics encrypted with a customer managed KMS key also need kms:GenerateDataKey and kms:Decrypt on that key.

Quick start

Send a message

1. Add Send Message. Queue mygame-reports (a name or a full URL), Body {"type":"bug","text":"..."}.
2. On Success returns the Message Id; On Failure carries Error > Code and Message.

Listen to a queue

1. On Begin Play add Listen To Queue with Queue mygame-events and Auto Delete on. Promote the return value to a variable.
2. From On Message read Message > Body. If the queue is subscribed to an SNS topic, use Unwrap SNS Notification first.
3. Call Stop Listening on the variable when you no longer need messages. The listener also stops by itself when its world is torn down (end of play, level change).

Push notifications

1. Get the device's push token (for example the Firebase Cloud Messaging token from your push plugin).
2. Call Register Push Device with the token and, as Custom User Data, your player id. Save the returned endpoint ARN and pass it as Existing Endpoint Arn on the next start.
3. Your backend publishes to the endpoint or to a topic the endpoint is subscribed to (Subscribe with Protocol application).

SQS nodes

All latent nodes run in the background, can be stopped with Cancel on their return value and fire exactly one final pin on the game thread. Queue takes a queue name or URL; empty = the settings' Default Queue.

Listen To Queue

Listen To Queue (Queue, Auto Delete, Max Messages, Wait Seconds, Visibility Timeout) keeps long-polling one queue in the background until it is stopped. Pins:

SNS nodes

Mobile push

Register Push Device follows the token management flow AWS recommends:

1. Without an Existing Endpoint Arn it creates the endpoint. When SNS answers that the token already exists with other attributes, the existing endpoint is reused and updated.
2. It then reads the endpoint. A deleted endpoint is created again; a different token, a disabled endpoint or changed Custom User Data are updated (Enabled = true).
3. On Success returns the endpoint ARN. Save it (for example in a save game) and pass it back next time so each device keeps one endpoint.

Getting the token itself is platform specific (Firebase Cloud Messaging on Android). QueueCast does not show notifications on the device; that is the job of the operating system and your push setup.

Functions

Credentials

Give the authenticated role more than the guest role, for example only signed-in players may register push devices.

C++ API

// Build.cs: PublicDependencyModuleNames.Add("QueueCast");
#include "QueueCastLibrary.h"

TMap<FString, FString> Attributes;
Attributes.Add(TEXT("type"), TEXT("bug"));
UQueueCastLibrary::SendToQueueNative(TEXT("mygame-reports"), TEXT("{\"text\":\"...\"}"), Attributes,
    FQueueCastNativeDelegate::CreateLambda([](const FQueueCastSendResult& Result, const FQueueCastError& Error)
    {
        // runs on the game thread; Error.Code is empty on success
    }));

UQueueCastLibrary::PublishNative(TEXT("arn:aws:sns:us-east-1:123456789012:mygame-player-events"),
    TEXT("Level complete"), FString(), FQueueCastNativeDelegate());

The latent node classes (UQueueCastListenAction and the others) can also be created from C++ through their static factory functions; bind the dynamic delegates, then call Activate().

Types

Settings

Project Settings > Plugins > QueueCast (saved to DefaultGame.ini). Changes apply to the next request.

Troubleshooting

Credits

© 2026 Alpha XP — alphaxp.net · Support: support@alphaxp.net. Includes the AWS SDK for C++ and the AWS Common Runtime (Apache License 2.0). For Unreal Engine 4.27 and 5.8.