Deepgram Security Basics

Deepgram Security Basics

Prerequisites

• A data classification and consent decision for the audio/transcript workload.
• Scoped project credentials in the approved secret manager, an owner, and an incident/revocation route.

Examples

Use a development credential and a licensed non-sensitive audio fixture to verify the integration, logging only an opaque request ID and outcome. If recordings, transcripts, or keys are exposed, restrict access, revoke credentials where applicable, and follow the organization’s incident process before continuing.

Overview

Security best practices for Deepgram integration: scoped API keys, key rotation, Deepgram's built-in PII redaction feature, client-side temporary keys, SSRF prevention for audio URLs, and audit logging.

Security Checklist

• API keys in environment variables or secret manager (never in code)
• Separate keys per environment (dev/staging/prod)
• Keys scoped to minimum required permissions
• Key rotation schedule (90 days recommended)
• Deepgram redact option enabled for PII-sensitive audio
• Audio URLs validated (HTTPS only, no private IPs)
• Audit logging on all transcription operations

Instructions

Step 1: Scoped API Keys

Create keys with minimal permissions in Console > Settings > API Keys:

// Production transcription service — only needs listen scope
const sttKey = process.env.DEEPGRAM_STT_KEY;  // Scope: listen

// TTS service — only needs speak scope
const ttsKey = process.env.DEEPGRAM_TTS_KEY;  // Scope: speak

// Monitoring dashboard — only needs usage read
const monitorKey = process.env.DEEPGRAM_MONITOR_KEY;  // Scope: usage:read

// Admin operations — separate key, restricted access
const adminKey = process.env.DEEPGRAM_ADMIN_KEY;  // Scope: manage, keys

Step 2: Deepgram Built-in PII Redaction

import { createClient } from '@deepgram/sdk';

const deepgram = createClient(process.env.DEEPGRAM_API_KEY!);

// Deepgram redacts PII directly in the transcript
const { result } = await deepgram.listen.prerecorded.transcribeUrl(
  { url: audioUrl },
  {
    model: 'nova-3',
    smart_format: true,
    // Built-in redaction — replaces sensitive data in transcript
    redact: ['pci', 'ssn', 'numbers'],
    // pci     — Credit card numbers → [REDACTED]
    // ssn     — Social Security numbers → [REDACTED]
    // numbers — All numeric sequences → [REDACTED]
  }
);

// Transcript will contain [REDACTED] in place of sensitive numbers
console.log(result.results.channels[0].alternatives[0].transcript);
// "My card number is [REDACTED] and my SSN is [REDACTED]"

Step 3: Temporary Keys for Client-Side

// Generate short-lived keys for browser/mobile clients
// This prevents exposing your main API key

import { createClient } from '@deepgram/sdk';
import express from 'express';

const app = express();
const deepgram = createClient(process.env.DEEPGRAM_API_KEY!);

app.post('/api/deepgram/token', async (req, res) => {
  // Create a temporary key that expires in 10 seconds
  // Use for browser WebSocket connections
  const { result, error } = await deepgram.manage.createProjectKey(
    process.env.DEEPGRAM_PROJECT_ID!,
    {
      comment: `temp-key-${Date.now()}`,
      scopes: ['listen'],          // Minimal scope
      time_to_live_in_seconds: 10, // Short-lived
    }
  );

  if (error) return res.status(500).json({ error: error.message });
  res.json({ key: result.key, expires_in: 10 });
});

// Browser client uses temporary key:
// const { key } = await fetch('/api/deepgram/token').then(r => r.json());
// const ws = new WebSocket('wss://api.deepgram.com/v1/listen', ['token', key]);

Step 4: Key Rotation

import { createClient } from '@deepgram/sdk';

async function rotateApiKey(projectId: string) {
  const admin = createClient(process.env.DEEPGRAM_ADMIN_KEY!);

  // 1. Create new key with same scopes
  const { result: newKey } = await admin.manage.createProjectKey(projectId, {
    comment: `rotated-${new Date().toISOString().split('T')[0]}`,
    scopes: ['listen', 'speak'],
    expiration_date: new Date(Date.now() + 90 * 86400000).toISOString(), // 90 days
  });
  console.log('New key created:', newKey.key_id);

  // 2. Update secret manager (example: GCP Secret Manager)
  // await updateSecret('DEEPGRAM_API_KEY', newKey.key);

  // 3. Validate new key works
  const testClient = createClient(newKey.key);
  const { error } = await testClient.manage.getProjects();
  if (error) throw new Error('New key validation failed — aborting rotation');

  // 4. Delete old key (after services have picked up new key)
  // await admin.manage.deleteProjectKey(projectId, oldKeyId);

  return newKey;
}

Step 5: Audio URL Validation (SSRF Prevention)

import { URL } from 'url';
import { lookup } from 'dns/promises';

async function validateAudioUrl(url: string): Promise<void> {
  const parsed = new URL(url);

  // Require HTTPS
  if (parsed.protocol !== 'https:') {
    throw new Error('Only HTTPS audio URLs allowed');
  }

  // Block private/internal IPs
  const { address } = await lookup(parsed.hostname);
  const privateRanges = [
    /^127\./, /^10\./, /^172\.(1[6-9]|2\d|3[01])\./, /^192\.168\./,
    /^0\./, /^169\.254\./, /^::1$/, /^fc00:/, /^fe80:/,
  ];
  if (privateRanges.some(r => r.test(address))) {
    throw new Error(`Blocked: ${parsed.hostname} resolves to private IP`);
  }

  // Block known internal hostnames
  const blockedHosts = ['localhost', 'metadata.google.internal', '169.254.169.254'];
  if (blockedHosts.includes(parsed.hostname)) {
    throw new Error(`Blocked hostname: ${parsed.hostname}`);
  }
}

// Use before transcription:
await validateAudioUrl(userProvidedUrl);
const { result } = await deepgram.listen.prerecorded.transcribeUrl(
  { url: userProvidedUrl }, { model: 'nova-3' }
);

Step 6: Audit Logging

interface AuditEntry {
  timestamp: string;
  action: 'transcribe' | 'tts' | 'key_create' | 'key_delete';
  userId: string;
  requestId?: string;
  model: string;
  audioDuration?: number;
  success: boolean;
  error?: string;
  ip?: string;
}

function logAudit(entry: AuditEntry) {
  // Structured JSON for log aggregation (Datadog, CloudWatch, etc.)
  const log = {
    ...entry,
    service: 'deepgram-integration',
    level: entry.success ? 'info' : 'error',
  };
  console.log(JSON.stringify(log));
}

// Usage in transcription middleware
async function transcribeWithAudit(userId: string, url: string, ip: string) {
  const start = Date.now();
  try {
    const { result, error } = await deepgram.listen.prerecorded.transcribeUrl(
      { url }, { model: 'nova-3', smart_format: true }
    );
    logAudit({
      timestamp: new Date().toISOString(),
      action: 'transcribe',
      userId, model: 'nova-3', ip,
      requestId: result?.metadata?.request_id,
      audioDuration: result?.metadata?.duration,
      success: !error,
      error: error?.message,
    });
    if (error) throw error;
    return result;
  } catch (err: any) {
    logAudit({
      timestamp: new Date().toISOString(),
      action: 'transcribe',
      userId, model: 'nova-3', ip,
      success: false, error: err.message,
    });
    throw err;
  }
}

Output

• Scoped API keys per service/environment
• Built-in PII redaction via redact parameter
• Temporary keys for client-side (browser/mobile)
• Key rotation with validation and cleanup
• SSRF-safe audio URL validation
• Structured audit logging

Error Handling

Resources

• API Key Management
• PII Redaction
• Deepgram Security
• SOC 2 / HIPAA