content-filtering-policy.xml

<policies>
    <inbound>
        <set-variable name="SubscriptionKey" value="@(context.Request.Headers.GetValueOrDefault("api-key"))" />
        <send-request mode="new" response-variable-name="safetyResponse">
            <set-url>@("https://" + context.Request.Headers.GetValueOrDefault("Host") + "/contentsafety/text:analyze?api-version=2023-10-01")</set-url>
            <set-method>POST</set-method>
            <set-header name="Ocp-Apim-Subscription-Key" exists-action="override">
                <value>@(context.Variables.GetValueOrDefault<string>("SubscriptionKey"))</value>
            </set-header>
            <set-header name="Content-Type" exists-action="override">
                <value>application/json</value>
            </set-header>
            <set-body>@{
            	string[] categories = new string[] {"Hate","Sexual","SelfHarm","Violence"};
				JObject obj = new JObject();
				JProperty textProperty = new JProperty("text", string.Concat(context.Request.Body.As<JObject>(preserveContent: true)["messages"].Select(m => m.Value<string>("content")).ToArray()));
				JProperty categoriesProperty = new JProperty("categories", new JArray(categories));
				JProperty outputTypeProperty = new JProperty("outputType", "EightSeverityLevels");
				obj.Add(textProperty);
				obj.Add(categoriesProperty);
				obj.Add(outputTypeProperty);
				return obj.ToString();
			}</set-body>
        </send-request>
        <choose>
            <when condition="@(((IResponse)context.Variables["safetyResponse"]).StatusCode == 200)">
                <set-variable name="thresholdExceededCategory" value="@{
                    var thresholdExceededCategory = "";

                    // Define the allowed threshold for each category
                    Dictionary<string, int> categoryThresholds = new Dictionary<string, int>()
                    {
                        { "Hate", 0 },
                        { "Sexual", 0 },
                        { "SelfHarm", 0 },
                        { "Violence", 0 }
                    };

                    foreach (var category in categoryThresholds)
                    {
                        var categoryAnalysis = ((JArray)((IResponse)context.Variables["safetyResponse"]).Body.As<JObject>(preserveContent: true)["categoriesAnalysis"]).FirstOrDefault(c => (string)c["category"] == category.Key);

                        if (categoryAnalysis != null && (int)categoryAnalysis["severity"] > category.Value)
                        {
                            // Threshold exceeded for the category
                            thresholdExceededCategory = category.Key;
                            break;
                        }
                    }
                    return thresholdExceededCategory;
                }" />
                <choose>
                    <when condition="@(context.Variables["thresholdExceededCategory"] != "")">
                        <return-response>
                            <set-status code="400" reason="Bad Request" />
                            <set-body>@{
                                var errorResponse = new
                                {
                                    error = new
                                    {
                                        message = "The content was filtered by the Azure AI Content Safety service for the category: " + (string)context.Variables["thresholdExceededCategory"]
                                    }
                                };
                                return JsonConvert.SerializeObject(errorResponse);
                            }</set-body>
                        </return-response>
                    </when>
                </choose>
            </when>
            <otherwise>
                <return-response>
                    <set-status code="500" reason="Internal Server Error" />
                </return-response>
            </otherwise>
        </choose>
        <base />
        <authentication-managed-identity resource="https://cognitiveservices.azure.com" output-token-variable-name="managed-id-access-token" ignore-error="false" />
        <set-header name="Authorization" exists-action="override">
            <value>@("Bearer " + (string)context.Variables["managed-id-access-token"])</value>
        </set-header>
        <set-backend-service backend-id="{backend-id}" />
    </inbound>
    <backend>
        <base />
    </backend>
    <outbound>
        <base />
        <set-header name="debug-content-safety-output" exists-action="override">
            <value>@(((IResponse)context.Variables["safetyResponse"]).Body.As<string>(preserveContent: true))</value>
        </set-header>
    </outbound>
    <on-error>
        <base />
    </on-error>
</policies>