Archive Genesys Cloud Media to AWS S3 with Node.js Lambda

What You Will Build

• A Lambda function that processes Genesys Cloud archiving events, downloads audio streams via pre-signed URLs, encrypts the payload with AES-256-GCM, uploads it to S3 with date partitioning, and writes storage references back to the interaction record.
• This implementation uses the Genesys Cloud Media API and Interactions API with raw HTTP calls for full control over token lifecycle and retry behavior.
• The code is written in Node.js 18+ using modern async/await syntax, the AWS SDK v3, and the native crypto module.

Prerequisites

• OAuth Client Credentials flow with scopes: media:view, interaction:metadata:update
• Genesys Cloud API v2
• Node.js 18+ runtime
• External dependencies: axios, @aws-sdk/client-s3, uuid

Authentication Setup

Genesys Cloud uses standard OAuth 2.0 client credentials grant. You must cache the access token and refresh it before expiration to avoid 401 errors during high-throughput archiving. The following module provides a token manager with TTL checking and automatic refresh.

const axios = require('axios');
const crypto = require('crypto');

/**
 * @typedef {Object} TokenCache
 * @property {string} accessToken
 * @property {number} expiresAt
 */

class GenesysAuth {
  constructor(clientId, clientSecret, environment) {
    this.clientId = clientId;
    this.clientSecret = clientSecret;
    this.environment = environment;
    this.tokenCache = null;
    this.tokenUrl = `https://api.${environment}/oauth/token`;
  }

  async getToken() {
    if (this.tokenCache && Date.now() < this.tokenCache.expiresAt - 60000) {
      return this.tokenCache.accessToken;
    }

    const response = await axios.post(
      this.tokenUrl,
      new URLSearchParams({
        grant_type: 'client_credentials',
        client_id: this.clientId,
        client_secret: this.clientSecret,
        scope: 'media:view interaction:metadata:update',
      }),
      { headers: { 'Content-Type': 'application/x-www-form-urlencoded' } }
    );

    const { access_token, expires_in } = response.data;
    this.tokenCache = {
      accessToken: access_token,
      expiresAt: Date.now() + (expires_in * 1000),
    };

    return access_token;
  }
}

module.exports = { GenesysAuth };

Expected OAuth Response:

{
  "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9...",
  "token_type": "Bearer",
  "expires_in": 28800,
  "scope": "media:view interaction:metadata:update"
}

The token cache subtracts 60 seconds from the expiration timestamp to provide a safety margin for network latency. The GenesysAuth class ensures the Lambda always holds a valid bearer token before making API calls.

Implementation

Step 1: Parse Archiving Event and Validate Payload

Event Subscriptions deliver archiving events to your Lambda via EventBridge or direct webhook. You must validate the event structure and extract the mediaId and interactionId before proceeding.

/**
 * @param {Object} event - Lambda event payload
 * @returns {{ mediaId: string, interactionId: string }}
 */
function parseArchivingEvent(event) {
  const data = event.detail?.data || event.data || event;
  
  if (!data.mediaId || !data.interactionId) {
    throw new Error('Invalid archiving event: missing mediaId or interactionId');
  }

  return {
    mediaId: data.mediaId,
    interactionId: data.interactionId,
  };
}

Required OAuth Scope: archiving:events:subscribe (used during subscription creation, not in Lambda execution)

This validation step prevents downstream failures when malformed events or test payloads reach the function. You should configure your Event Subscription filter to only send archiving:events with eventType: "media" and status: "complete".

Step 2: Fetch Pre-signed URL from Media API

The Media API returns a time-limited pre-signed URL for secure download. You must handle 403 and 429 responses explicitly.

const axios = require('axios');

/**
 * @param {string} mediaId
 * @param {GenesysAuth} auth
 * @returns {Promise<string>}
 */
async function getMediaDownloadUrl(mediaId, auth) {
  const token = await auth.getToken();
  const baseUrl = `https://api.${auth.environment}/api/v2/media/${mediaId}`;

  try {
    const response = await axios.get(baseUrl, {
      headers: { Authorization: `Bearer ${token}` },
      timeout: 5000,
    });

    if (!response.data.downloadUrl) {
      throw new Error('Media object does not contain a downloadUrl');
    }

    return response.data.downloadUrl;
  } catch (error) {
    if (error.response?.status === 401) {
      throw new Error('Authentication failed: invalid or expired token');
    }
    if (error.response?.status === 403) {
      throw new Error(`Forbidden: insufficient scopes for media ${mediaId}`);
    }
    if (error.response?.status === 429) {
      const retryAfter = error.response.headers['retry-after'] * 1000 || 2000;
      await new Promise((resolve) => setTimeout(resolve, retryAfter));
      return getMediaDownloadUrl(mediaId, auth);
    }
    throw error;
  }
}

Required OAuth Scope: media:view

Realistic API Response:

{
  "id": "a1b2c3d4-5678-90ab-cdef-1234567890ab",
  "downloadUrl": "https://s3.amazonaws.com/genesys-media-archive/a1b2c3d4.wav?X-Amz-Algorithm=AWS4-HMAC-SHA256&...",
  "status": "complete",
  "mediaType": "audio",
  "duration": 145000
}

The pre-signed URL expires typically within 5 minutes. You must consume it immediately after retrieval. The 429 handler implements a single automatic retry with Retry-After header compliance.

Step 3: Download, Encrypt, and Upload with Adaptive Retry

This step streams the audio file, encrypts it with AES-256-GCM, and uploads to S3. S3 throttling requires adaptive exponential backoff with jitter.

const { S3Client, PutObjectCommand } = require('@aws-sdk/client-s3');
const crypto = require('crypto');
const stream = require('stream/promises');

const s3Client = new S3Client({ region: process.env.AWS_REGION });

/**
 * @param {string} downloadUrl
 * @param {string} s3Bucket
 * @param {string} mediaId
 * @returns {Promise<string>} S3 object key
 */
async function downloadEncryptAndUpload(downloadUrl, s3Bucket, mediaId) {
  const key = Buffer.from(process.env.ENCRYPTION_KEY_HEX, 'hex');
  const iv = crypto.randomBytes(12);
  const algorithm = 'aes-256-gcm';
  const cipher = crypto.createCipheriv(algorithm, key, iv);

  const downloadResponse = await axios.get(downloadUrl, { responseType: 'stream' });
  
  const encryptedStream = downloadResponse.data.pipe(cipher);
  
  // Collect encrypted chunks
  const chunks = [];
  for await (const chunk of encryptedStream) {
    chunks.push(chunk);
  }
  const encryptedBuffer = Buffer.concat(chunks);
  const authTag = cipher.getAuthTag();

  // Date partitioning
  const now = new Date();
  const datePath = `${now.getFullYear()}/${String(now.getMonth() + 1).padStart(2, '0')}/${String(now.getDate()).padStart(2, '0')}`;
  const s3Key = `archive/${datePath}/${mediaId}.enc`;

  // Combine encrypted data and auth tag for storage
  const payload = Buffer.concat([encryptedBuffer, authTag]);

  const putCommand = new PutObjectCommand({
    Bucket: s3Bucket,
    Key: s3Key,
    Body: payload,
    ContentType: 'application/octet-stream',
    Metadata: {
      encryption: algorithm,
      iv: iv.toString('base64'),
    },
  });

  // Adaptive retry logic for S3 throttling
  let attempt = 0;
  const maxRetries = 5;
  while (attempt <= maxRetries) {
    try {
      await s3Client.send(putCommand);
      return s3Key;
    } catch (error) {
      const isThrottled = error.name === 'Throttling' || error.name === 'SlowDown' || error.statusCode === 503;
      if (!isThrottled || attempt === maxRetries) {
        throw error;
      }
      const baseDelay = Math.pow(2, attempt) * 1000;
      const jitter = Math.random() * 1000;
      const delay = Math.min(baseDelay + jitter, 30000);
      console.warn(`S3 throttling detected. Retrying in ${Math.round(delay)}ms (attempt ${attempt + 1})`);
      await new Promise((resolve) => setTimeout(resolve, delay));
      attempt++;
    }
  }
}

Required OAuth Scope: None (S3 uses IAM roles)

The AES-256-GCM implementation appends the authentication tag to the ciphertext. The metadata object stores the initialization vector for future decryption. The retry loop caps at 30 seconds maximum delay to respect Lambda execution timeouts.

Step 4: Update Interaction Metadata via Interactions API

After successful upload, you must persist the S3 reference back to Genesys Cloud. This enables auditors and downstream systems to locate the archived media.

/**
 * @param {string} interactionId
 * @param {string} s3Key
 * @param {GenesysAuth} auth
 */
async function updateInteractionMetadata(interactionId, s3Key, auth) {
  const token = await auth.getToken();
  const baseUrl = `https://api.${auth.environment}/api/v2/interactions/${interactionId}`;

  const payload = {
    metadata: {
      s3_archive_key: s3Key,
      archive_timestamp: new Date().toISOString(),
      encryption_algorithm: 'AES-256-GCM',
    },
  };

  try {
    await axios.patch(baseUrl, payload, {
      headers: { 
        Authorization: `Bearer ${token}`,
        'Content-Type': 'application/json',
      },
      timeout: 5000,
    });
  } catch (error) {
    if (error.response?.status === 404) {
      throw new Error(`Interaction ${interactionId} not found`);
    }
    if (error.response?.status === 429) {
      const retryAfter = error.response.headers['retry-after'] * 1000 || 2000;
      await new Promise((resolve) => setTimeout(resolve, retryAfter));
      return updateInteractionMetadata(interactionId, s3Key, auth);
    }
    throw new Error(`Failed to update interaction metadata: ${error.message}`);
  }
}

Required OAuth Scope: interaction:metadata:update

Realistic Request Body:

{
  "metadata": {
    "s3_archive_key": "archive/2024/05/20/a1b2c3d4-5678-90ab-cdef-1234567890ab.enc",
    "archive_timestamp": "2024-05-20T14:32:10.000Z",
    "encryption_algorithm": "AES-256-GCM"
  }
}

The PATCH operation merges the provided metadata keys with existing interaction data. You do not need to retrieve the full interaction object first.

Complete Working Example

const axios = require('axios');
const { GenesysAuth } = require('./auth');
const { downloadEncryptAndUpload } = require('./s3-encrypt');

exports.handler = async (event) => {
  const auth = new GenesysAuth(
    process.env.GENESYS_CLIENT_ID,
    process.env.GENESYS_CLIENT_SECRET,
    process.env.GENESYS_ENVIRONMENT
  );

  try {
    const { mediaId, interactionId } = parseArchivingEvent(event);
    console.log(`Processing archive for mediaId: ${mediaId}`);

    const downloadUrl = await getMediaDownloadUrl(mediaId, auth);
    const s3Key = await downloadEncryptAndUpload(
      downloadUrl,
      process.env.S3_ARCHIVE_BUCKET,
      mediaId
    );

    await updateInteractionMetadata(interactionId, s3Key, auth);
    console.log(`Successfully archived media ${mediaId} to ${s3Key}`);

    return { statusCode: 200, body: JSON.stringify({ success: true, s3Key }) };
  } catch (error) {
    console.error('Archive pipeline failed:', error);
    return { statusCode: 500, body: JSON.stringify({ error: error.message }) };
  }
};

// Helper functions from Step 1, 2, and 4 must be included in the same module 
// or imported from separate files. The structure above assumes modular imports.

Deploy this handler with a Lambda runtime of Node.js 18 or 20. Configure environment variables for GENESYS_CLIENT_ID, GENESYS_CLIENT_SECRET, GENESYS_ENVIRONMENT, S3_ARCHIVE_BUCKET, and ENCRYPTION_KEY_HEX. Attach an IAM role with s3:PutObject permissions to the target bucket.

Common Errors & Debugging

Error: 401 Unauthorized on Media API

• Cause: The OAuth token expired during long-running Lambda execution or the client credentials are misconfigured.
• Fix: Verify the token cache logic subtracts a buffer before expiration. Ensure the OAuth client has the media:view scope assigned in the Genesys Cloud admin console.
• Code showing the fix: The GenesysAuth.getToken() method already implements TTL validation. Add logging to track token refresh times.

Error: 429 Too Many Requests on Interactions API

• Cause: High-volume archiving events exceed the Genesys Cloud API rate limits.
• Fix: Implement request batching or increase the retry delay. The updateInteractionMetadata function already reads the Retry-After header and backs off accordingly.
• Code showing the fix: Increase the base delay in the 429 handler to retryAfter * 1000 * 1.5 to add additional headroom.

Error: S3 Throttling / SlowDown

• Cause: Concurrent Lambda executions exceed S3 PUT request limits for the partition key prefix.
• Fix: The adaptive retry loop in downloadEncryptAndUpload handles this automatically. Ensure your Lambda concurrency limit does not exceed 500 simultaneous executions for a single bucket prefix.
• Code showing the fix: The while (attempt <= maxRetries) block implements exponential backoff with jitter. Monitor CloudWatch metrics for Throttling errors and adjust maxRetries if necessary.

Error: GCM Tag Mismatch During Decryption

• Cause: The authentication tag was truncated or the IV was not preserved correctly.
• Fix: Ensure the decryption routine reads the last 16 bytes of the stored payload as the auth tag, and uses the IV from S3 object metadata. The upload function concatenates encryptedBuffer and authTag in that exact order.
• Code showing the fix: Verify decryption code uses crypto.createDecipheriv(algorithm, key, iv) and calls decipher.setAuthTag(authTag) before piping the stream.

Official References

• Genesys Cloud Media API Documentation
• Genesys Cloud Interactions API Documentation
• Genesys Cloud OAuth 2.0 Client Credentials Flow
• AWS SDK v3 S3 Client Reference
• Node.js Crypto Module Documentation