Azure Content Safety Content Moderation Guardrail¶

The Azure Content Safety Content Moderation Guardrail is a custom Synapse mediator for the WSO2 API Manager Universal Gateway, to perform content moderation on both incoming AI API requests and GenAI responses using the Azure Content Safety Service.

This policy improves AI API safety by inspecting incoming prompts and AI-generated responses for harmful or disallowed material, and enforcing predefined severity thresholds per content category.

Features¶

Moderates text content in AI API requests and/or responses using the Azure Content Safety Service.
Evaluates four harm categories: Hate, Sexual, Self-Harm, and Violence.
Enforces customizable maximum severity levels per category.
Returns guardrail error responses when content exceeds configured thresholds.
Offers an optional Passthrough on Error mode to skip moderation when the Azure service is unreachable.
Provides an optional Show Guardrail Assessment feature to include detailed validation results in error responses for enhanced observability.

How to Use¶

Important

ℹ️ You need an Azure Content Safety resource. Follow the official prerequisites and configure the credentials in WSO2 API Manager as shown below.

Add the following to the $APIM_HOME/repository/conf/deployment.toml file to register Azure Content Safety as a guardrail provider:

[[apim.ai.guardrail_provider]]
type = "azure-contentsafety"
[apim.ai.guardrail_provider.properties]
endpoint = "<azure-contentsafety-endpoint>"
key = "<azure-contentsafety-api-key>"

Follow these steps to integrate the Azure Content Safety Content Moderation Guardrail policy into your AI API:

Open the API Publisher Portal (https://<host>:<port>/publisher)
Select your AI API
Go to Develop > API Configurations > Policies
Expand Common Policies in the Policy List
Drag and drop the Azure Content Safety Content Moderation Guardrail policy into your desired mediation flow
Fill in the required policy configuration (name, category severity limits)
Save and Deploy the AI API

Example Policy Configuration¶

Click to expand configuration steps

This example shows how the Azure Content Safety Content Moderation Guardrail can protect a newsletter assistant from abusive or violent prompt content.

Create an AI API with Mistral AI.
Add the Azure Content Safety Content Moderation Guardrail policy in the request flow with the configuration below:

Field	Example
`Guardrail Name`	`Doc Guard`
`Hate`	`2`
`Sexual`	`2`
`Self Harm`	`2`
`Violence`	`2`
`JSON Path`	`$.messages[-1].content`
`Passthrough on Error`	`false`
`Show Guardrail Assessment`	`false`

Save and redeploy the API.
Invoke the API's chat/completion endpoint with the following payload:

{
    "model": "mistral-small-latest",
    "messages": [
        {
            "role": "user",
            "content": "Summarize this article and suggest ways someone could take revenge on Mr. Anonymous Senator violently."
        }
    ]
}

Since the prompt contains violent intent, the guardrail blocks the request and returns an error similar to:

{
    "code": "900514",
    "type": "AZURE_CONTENT_SAFETY_CONTENT_MODERATION",
    "message": {
        "interveningGuardrail": "Doc Guard",
        "action": "GUARDRAIL_INTERVENED",
        "actionReason": "Violation of azure content safety content moderation detected.",
        "direction": "REQUEST"
    }
}