Use DescribeAnomalyDetectors with an AWS SDK or CLI

    /// <summary>
    /// Describe anomaly detectors for a metric and namespace.
    /// </summary>
    /// <param name="metricNamespace">The namespace of the metric.</param>
    /// <param name="metricName">The metric of the anomaly detectors.</param>
    /// <returns>The list of detectors.</returns>
    public async Task<List<AnomalyDetector>> DescribeAnomalyDetectors(string metricNamespace, string metricName)
    {
        List<AnomalyDetector> detectors = new List<AnomalyDetector>();
        var paginatedDescribeAnomalyDetectors = _amazonCloudWatch.Paginators.DescribeAnomalyDetectors(
            new DescribeAnomalyDetectorsRequest()
            {
                MetricName = metricName,
                Namespace = metricNamespace
            });

        await foreach (var data in paginatedDescribeAnomalyDetectors.AnomalyDetectors)
        {
            detectors.Add(data);
        }

        return detectors;
    }

To retrieve a list of anomaly detection models

The following describe-anomaly-detectors example displays information about anomaly detector models that are associated with the AWS/Logs namespace in the specified account.

aws cloudwatch describe-anomaly-detectors \
    --namespace AWS/Logs

Output:

{
    "AnomalyDetectors": [
        {
            "Namespace": "AWS/Logs",
            "MetricName": "IncomingBytes",
            "Dimensions": [],
            "Stat": "SampleCount",
            "Configuration": {
                "ExcludedTimeRanges": []
            },
            "StateValue": "TRAINED",
            "SingleMetricAnomalyDetector": {
                "AccountId": "123456789012",
                "Namespace": "AWS/Logs",
                "MetricName": "IncomingBytes",
                "Dimensions": [],
                "Stat": "SampleCount"
            }
        },
        {
            "Namespace": "AWS/Logs",
            "MetricName": "IncomingBytes",
            "Dimensions": [
                {
                    "Name": "LogGroupName",
                    "Value": "demo"
                }
            ],
            "Stat": "Average",
            "Configuration": {
                "ExcludedTimeRanges": []
            },
            "StateValue": "PENDING_TRAINING",
            "SingleMetricAnomalyDetector": {
                "AccountId": "123456789012",
                "Namespace": "AWS/Logs",
                "MetricName": "IncomingBytes",
                "Dimensions": [
                    {
                        "Name": "LogGroupName",
                        "Value": "demo"
                    }
                ],
                "Stat": "Average"
            }
        }
    ]
}

For more information, see Using CloudWatch anomaly detection in the Amazon CloudWatch User Guide.

    /**
     * Describes the anomaly detectors based on the specified JSON file.
     *
     * @param fileName the name of the JSON file containing the custom metric namespace and name
     * @return a {@link CompletableFuture} that completes when the anomaly detectors have been described
     * @throws RuntimeException if there is a failure during the operation, such as when reading or parsing the JSON file,
     *                          or when describing the anomaly detectors
     */
    public CompletableFuture<Void> describeAnomalyDetectorsAsync(String fileName) {
        CompletableFuture<JsonNode> readFileFuture = CompletableFuture.supplyAsync(() -> {
            try {
                JsonParser parser = new JsonFactory().createParser(new File(fileName));
                return new ObjectMapper().readTree(parser);
            } catch (IOException e) {
                throw new RuntimeException("Failed to read or parse the file", e);
            }
        });

        return readFileFuture.thenCompose(rootNode -> {
            try {
                String customMetricNamespace = rootNode.findValue("customMetricNamespace").asText();
                String customMetricName = rootNode.findValue("customMetricName").asText();

                DescribeAnomalyDetectorsRequest detectorsRequest = DescribeAnomalyDetectorsRequest.builder()
                    .maxResults(10)
                    .metricName(customMetricName)
                    .namespace(customMetricNamespace)
                    .build();

                return getAsyncClient().describeAnomalyDetectors(detectorsRequest).thenAccept(response -> {
                    List<AnomalyDetector> anomalyDetectorList = response.anomalyDetectors();
                    for (AnomalyDetector detector : anomalyDetectorList) {
                        logger.info("Metric name: {} ", detector.singleMetricAnomalyDetector().metricName());
                        logger.info("State: {} ", detector.stateValue());
                    }
                });
            } catch (RuntimeException e) {
                throw new RuntimeException("Failed to describe anomaly detectors", e);
            }
        }).whenComplete((result, exception) -> {
            if (exception != null) {
                throw new RuntimeException("Error describing anomaly detectors", exception);
            }
        });
    }

suspend fun describeAnomalyDetectors(fileName: String) {
    // Read values from the JSON file.
    val parser = JsonFactory().createParser(File(fileName))
    val rootNode = ObjectMapper().readTree<JsonNode>(parser)
    val customMetricNamespace = rootNode.findValue("customMetricNamespace").asText()
    val customMetricName = rootNode.findValue("customMetricName").asText()

    val detectorsRequest =
        DescribeAnomalyDetectorsRequest {
            maxResults = 10
            metricName = customMetricName
            namespace = customMetricNamespace
        }
    CloudWatchClient { region = "us-east-1" }.use { cwClient ->
        val response = cwClient.describeAnomalyDetectors(detectorsRequest)
        response.anomalyDetectors?.forEach { detector ->
            println("Metric name: ${detector.singleMetricAnomalyDetector?.metricName}")
            println("State: ${detector.stateValue}")
        }
    }
}