Azure AI Content Safety REST SDK for TypeScript

Analyze text and images for harmful content with customizable blocklists.

Installation

npm install @azure-rest/ai-content-safety @azure/identity @azure/core-auth

Environment Variables

CONTENT_SAFETY_ENDPOINT=https://<resource>.cognitiveservices.azure.com
CONTENT_SAFETY_KEY=<api-key>

Authentication

Important: This is a REST client. ContentSafetyClient is a function, not a class.

API Key

import ContentSafetyClient from "@azure-rest/ai-content-safety";
import { AzureKeyCredential } from "@azure/core-auth";

const client = ContentSafetyClient(
  process.env.CONTENT_SAFETY_ENDPOINT!,
  new AzureKeyCredential(process.env.CONTENT_SAFETY_KEY!)
);

DefaultAzureCredential

import ContentSafetyClient from "@azure-rest/ai-content-safety";
import { DefaultAzureCredential } from "@azure/identity";

const client = ContentSafetyClient(
  process.env.CONTENT_SAFETY_ENDPOINT!,
  new DefaultAzureCredential()
);

Analyze Text

import ContentSafetyClient, { isUnexpected } from "@azure-rest/ai-content-safety";

const result = await client.path("/text:analyze").post({
  body: {
    text: "Text content to analyze",
    categories: ["Hate", "Sexual", "Violence", "SelfHarm"],
    outputType: "FourSeverityLevels"  // or "EightSeverityLevels"
  }
});

if (isUnexpected(result)) {
  throw result.body;
}

for (const analysis of result.body.categoriesAnalysis) {
  console.log(`${analysis.category}: severity ${analysis.severity}`);
}

Analyze Image

Base64 Content

import { readFileSync } from "node:fs";

const imageBuffer = readFileSync("./image.png");
const base64Image = imageBuffer.toString("base64");

const result = await client.path("/image:analyze").post({
  body: {
    image: { content: base64Image }
  }
});

if (isUnexpected(result)) {
  throw result.body;
}

for (const analysis of result.body.categoriesAnalysis) {
  console.log(`${analysis.category}: severity ${analysis.severity}`);
}

Blob URL

const result = await client.path("/image:analyze").post({
  body: {
    image: { blobUrl: "https://storage.blob.core.windows.net/container/image.png" }
  }
});

Blocklist Management

Create Blocklist

const result = await client
  .path("/text/blocklists/{blocklistName}", "my-blocklist")
  .patch({
    contentType: "application/merge-patch+json",
    body: {
      description: "Custom blocklist for prohibited terms"
    }
  });

if (isUnexpected(result)) {
  throw result.body;
}

console.log(`Created: ${result.body.blocklistName}`);

Add Items to Blocklist

const result = await client
  .path("/text/blocklists/{blocklistName}:addOrUpdateBlocklistItems", "my-blocklist")
  .post({
    body: {
      blocklistItems: [
        { text: "prohibited-term-1", description: "First blocked term" },
        { text: "prohibited-term-2", description: "Second blocked term" }
      ]
    }
  });

if (isUnexpected(result)) {
  throw result.body;
}

for (const item of result.body.blocklistItems ?? []) {
  console.log(`Added: ${item.blocklistItemId}`);
}

Analyze with Blocklist

const result = await client.path("/text:analyze").post({
  body: {
    text: "Text that might contain blocked terms",
    blocklistNames: ["my-blocklist"],
    haltOnBlocklistHit: false
  }
});

if (isUnexpected(result)) {
  throw result.body;
}

// Check blocklist matches
if (result.body.blocklistsMatch) {
  for (const match of result.body.blocklistsMatch) {
    console.log(`Blocked: "${match.blocklistItemText}" from ${match.blocklistName}`);
  }
}

List Blocklists

const result = await client.path("/text/blocklists").get();

if (isUnexpected(result)) {
  throw result.body;
}

for (const blocklist of result.body.value ?? []) {
  console.log(`${blocklist.blocklistName}: ${blocklist.description}`);
}

Delete Blocklist

await client.path("/text/blocklists/{blocklistName}", "my-blocklist").delete();

Harm Categories

Category	API Term	Description
Hate and Fairness	Hate	Discriminatory language targeting identity groups
Sexual	Sexual	Sexual content, nudity, pornography
Violence	Violence	Physical harm, weapons, terrorism
Self-Harm	SelfHarm	Self-injury, suicide, eating disorders

Severity Levels

Level	Risk	Recommended Action
0	Safe	Allow
2	Low	Review or allow with warning
4	Medium	Block or require human review
6	High	Block immediately

Output Types:

• FourSeverityLevels (default): Returns 0, 2, 4, 6
• EightSeverityLevels: Returns 0-7

Content Moderation Helper

import ContentSafetyClient, { 
  isUnexpected, 
  TextCategoriesAnalysisOutput 
} from "@azure-rest/ai-content-safety";

interface ModerationResult {
  isAllowed: boolean;
  flaggedCategories: string[];
  maxSeverity: number;
  blocklistMatches: string[];
}

async function moderateContent(
  client: ReturnType<typeof ContentSafetyClient>,
  text: string,
  maxAllowedSeverity = 2,
  blocklistNames: string[] = []
): Promise<ModerationResult> {
  const result = await client.path("/text:analyze").post({
    body: { text, blocklistNames, haltOnBlocklistHit: false }
  });

  if (isUnexpected(result)) {
    throw result.body;
  }

  const analyses = result.body.categoriesAnalysis;
  const expected = ["Hate", "SelfHarm", "Sexual", "Violence"];
  if (!Array.isArray(analyses) || expected.some(category =>
    !analyses.some(c => c.category === category && Number.isInteger(c.severity) && c.severity! >= 0 && c.severity! <= 7))) {
    throw new Error("Incomplete moderation assessment");
  }

  const flaggedCategories = analyses
    .filter(c => c.severity! > maxAllowedSeverity)
    .map(c => c.category!);

  const maxSeverity = Math.max(
    ...analyses.map(c => c.severity!)
  );

  const blocklistMatches = (result.body.blocklistsMatch ?? [])
    .map(m => m.blocklistItemText!);

  return {
    isAllowed: flaggedCategories.length === 0 && blocklistMatches.length === 0,
    flaggedCategories,
    maxSeverity,
    blocklistMatches
  };
}

API Endpoints

Operation	Method	Path
Analyze Text	POST	/text:analyze
Analyze Image	POST	/image:analyze
Create/Update Blocklist	PATCH	/text/blocklists/{blocklistName}
List Blocklists	GET	/text/blocklists
Delete Blocklist	DELETE	/text/blocklists/{blocklistName}
Add Blocklist Items	POST	/text/blocklists/{blocklistName}:addOrUpdateBlocklistItems
List Blocklist Items	GET	/text/blocklists/{blocklistName}/blocklistItems
Remove Blocklist Items	POST	/text/blocklists/{blocklistName}:removeBlocklistItems

Key Types

import ContentSafetyClient, {
  isUnexpected,
  AnalyzeTextParameters,
  AnalyzeImageParameters,
  TextCategoriesAnalysisOutput,
  ImageCategoriesAnalysisOutput,
  TextBlocklist,
  TextBlocklistItem
} from "@azure-rest/ai-content-safety";

Best Practices

1. Always use isUnexpected() - Type guard for error handling
2. Set appropriate thresholds - Different categories may need different severity thresholds
3. Use blocklists for domain-specific terms - Supplement AI detection with custom rules
4. Log moderation decisions - Keep audit trail for compliance
5. Handle edge cases - Empty text, very long text, unsupported image formats

When to Use

This skill is applicable to execute the workflow or actions described in the overview.

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.

A zero severity is a model result, not proof of safety; calibrate thresholds and escalation for the application. Missing analyses and service failures remain unassessed. Authorize cloud transmission of private content and do not expose raw error bodies or blocklisted text in public logs.