Track Amazon SNS operations in your test diagrams using the Kronikol.Extensions.SNS NuGet package. This extension intercepts SNS HTTP traffic via the AWS SDK's HttpClientFactory pipeline and logs operations for diagram generation.

Using a shared library or abstraction layer? If your code doesn't use the SNS SDK directly — e.g. it goes through MassTransit, a shared messaging library, or a custom abstraction — see the MassTransit Extension or Tracking Custom Dependencies for alternative approaches including MessageTracker and TrackingProxy<T>.

dotnet add package Kronikol.Extensions.SNS

using Amazon.SimpleNotificationService;
using Kronikol.Extensions.SNS;

var config = new AmazonSimpleNotificationServiceConfig
{
    RegionEndpoint = Amazon.RegionEndpoint.EUWest1
}
.WithTestTracking(new SnsTrackingMessageHandlerOptions
{
    ServiceName = "SNS",
    CallerName = "OrdersApi",
    Verbosity = SnsTrackingVerbosity.Detailed,
    CurrentTestInfoFetcher = () => (TestContext.CurrentTestName, TestContext.CurrentTestId)
});

var client = new AmazonSimpleNotificationServiceClient(config);

The extension uses the same DelegatingHandler pattern as the S3, DynamoDB, and SQS extensions. WithTestTracking() injects a SnsTrackingMessageHandler via AmazonSimpleNotificationServiceConfig.HttpClientFactory, intercepting all HTTP requests made by the SNS SDK.

The handler:

1. Reads and classifies each request using SnsOperationClassifier
2. Reconstructs the request body so downstream processing is unaffected
3. Logs request/response pairs via RequestResponseLogger

SNS supports two protocols:

Both protocols are fully supported by the classifier.

Unrecognised operations are classified as SnsOperation.Other.

The classifier extracts topic names from ARN fields in the request body:

1. TopicArn field: "TopicArn": "arn:aws:sns:us-east-1:123456789012:my-topic" → my-topic
2. TargetArn field: "TargetArn": "arn:aws:sns:us-east-1:123456789012:endpoint-topic" → endpoint-topic (used for direct publish to platform endpoints)

The topic name is extracted from the last segment of the ARN (after the final :). FIFO topic names (e.g. orders.fifo) are preserved with the .fifo suffix. The full ARN is also available via SnsOperationInfo.TopicArn.

Minimal output for clean diagrams:

• Method label: Operation name (e.g. Publish)
• URI: sns:///my-topic
• Content: Omitted (both request and response)
• Headers: Omitted
• Other operations: Skipped entirely

Balanced output for debugging:

• Method label: Operation name (e.g. Publish)
• URI: sns:///my-topic
• Content: Included (request body and response body)
• Headers: Included (with default exclusions)

Full HTTP-level output:

• Method: POST (actual HTTP method)
• URI: Original AWS endpoint URL
• Content: Full request/response bodies
• Headers: All headers (with default exclusions)
• Other operations: Included

new SnsTrackingMessageHandlerOptions
{
    // Display name for this SNS instance in diagrams
    ServiceName = "SNS",

    // Name of the calling service in diagrams
    CallerName = "OrdersApi",

    // Verbosity level (default: Detailed)
    Verbosity = SnsTrackingVerbosity.Detailed,

    // Required: provides test context for log correlation
    CurrentTestInfoFetcher = () => (testName, testId),

    // Headers excluded from logging (defaults below)
    ExcludedHeaders = new HashSet<string>
    {
        "Authorization", "x-amz-date", "x-amz-security-token",
        "x-amz-content-sha256", "User-Agent", "amz-sdk-invocation-id",
        "amz-sdk-request"
    }
}

v2.23.0+ Dual-Resolution: SnsTrackingMessageHandler accepts an optional IHttpContextAccessor? httpContextAccessor constructor parameter for resolving test identity from HTTP request headers when running inside the SUT's request pipeline. v2.26.3+: Set HttpContextAccessor on SnsTrackingMessageHandlerOptions instead — the tracker reads it automatically. See HTTP Tracking Setup#Dual-Resolution Test Identity (v2.23.0+) for details.

SnsTrackingMessageHandler implements ITrackingComponent and auto-registers with TrackingComponentRegistry on construction. This provides:

• ComponentName: "SnsTrackingMessageHandler ({ServiceName})"
• WasInvoked: true after first request
• InvocationCount: Total requests processed

Classified requests use the sns:/// URI scheme with the topic name in the path:

sns:///my-topic
sns:///orders.fifo
sns:///           (when topic name unavailable, e.g. ListTopics)

The path-based format (three slashes) preserves topic name casing, unlike host-based URIs which lowercase per RFC 3986.

The most common SNS pattern is fan-out to SQS queues. When using both extensions together:

• The SNS extension tracks the publish side (Publish → my-topic)
• The SQS extension tracks the receive side (ReceiveMessage from my-queue)

Together they show the complete message flow in your test diagrams.

• Integration: Amazon SQS Extension
• Integration: Amazon S3 Extension
• Integration: Amazon DynamoDB Extension
• Integration: Azure Service Bus Extension