> ## Documentation Index
> Fetch the complete documentation index at: https://docs.transmit.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Enterprise Security

> Enterprise-grade security with encryption at rest and in transit

## Security Overview

At Transmit, security is foundational to everything we build. We employ industry-leading security practices to protect your data, ensure privacy, and maintain the highest levels of compliance.

<CardGroup cols={2}>
  <Card title="SOC 2 Type II In Progress" icon="shield-check">
    Working towards certification with independently audited controls
  </Card>

  <Card title="End-to-End Encryption" icon="lock">
    Data encrypted at rest and in transit
  </Card>

  <Card title="Zero Trust Architecture" icon="network-wired">
    Every request authenticated and authorized
  </Card>

  <Card title="Regular Security Audits" icon="magnifying-glass">
    Continuous monitoring and penetration testing
  </Card>
</CardGroup>

## Data Encryption

### Encryption in Transit

All data transmitted to and from Transmit is encrypted using industry-standard protocols:

* **TLS 1.3** for all API connections
* **Perfect Forward Secrecy (PFS)** to protect past sessions
* **Strong cipher suites** (AES-256-GCM, ChaCha20-Poly1305)
* **Certificate pinning** available for enhanced security
* **HSTS (HTTP Strict Transport Security)** enforced

```typescript theme={null}
// All API calls are automatically encrypted
const response = await client.emails.send({
  from: 'hello@yourdomain.com',
  to: 'user@example.com',
  subject: 'Secure Communication',
  html: '<p>This message is encrypted in transit</p>'
});
// ✅ Data encrypted with TLS 1.3 automatically
```

### Encryption at Rest

All data stored in Transmit's infrastructure is encrypted:

* **AES-256 encryption** for all stored data
* **Separate encryption keys** per customer (multi-tenant isolation)
* **Hardware Security Modules (HSM)** for key management
* **Encrypted backups** with separate key rotation
* **Automatic key rotation** on a regular schedule

**What we encrypt:**

* Email content and attachments
* SMS message bodies
* Contact information
* API keys (hashed with bcrypt)
* Webhook payloads in queue
* Audit logs and analytics data

## API Security

### Authentication

Transmit uses bearer token authentication with strong security controls:

```bash theme={null}
curl https://api.transmit.dev/v1/emails \
  -H "Authorization: Bearer tx_live_abc123..." \
  -H "Content-Type: application/json"
```

**Security features:**

* API keys are cryptographically random (256-bit entropy)
* Keys are hashed using bcrypt before storage
* Support for multiple keys per organization
* Ability to scope keys to specific permissions
* Automatic key expiration policies available
* Rate limiting per key to prevent abuse

### API Key Best Practices

<AccordionGroup>
  <Accordion title="Never Expose Keys in Client-Side Code" icon="eye-slash">
    API keys should only be used server-side. Never include them in:

    * Frontend JavaScript code
    * Mobile apps
    * Public repositories
    * Version control systems
  </Accordion>

  <Accordion title="Use Environment Variables" icon="key">
    Store keys in environment variables or secrets management:

    ```bash theme={null}
    # .env (never commit this file)
    TRANSMIT_API_KEY=tx_live_abc123...
    ```

    ```typescript theme={null}
    import { Transmit } from 'transmitdev';

    const client = new Transmit({
      apiKey: process.env.TRANSMIT_API_KEY
    });
    ```
  </Accordion>

  <Accordion title="Rotate Keys Regularly" icon="rotate">
    Generate new API keys periodically:

    * Create new key in dashboard
    * Update your application
    * Verify new key works
    * Revoke old key

    Recommended rotation schedule: every 90 days
  </Accordion>

  <Accordion title="Use Different Keys per Environment" icon="server">
    Separate keys for different environments:

    * Development: `tx_test_dev_...`
    * Staging: `tx_test_staging_...`
    * Production: `tx_live_prod_...`

    This limits blast radius if a key is compromised.
  </Accordion>

  <Accordion title="Monitor Key Usage" icon="chart-line">
    Regularly check your dashboard for:

    * Unusual request patterns
    * Failed authentication attempts
    * Unexpected geographic access
    * Spike in usage

    Set up alerts for suspicious activity.
  </Accordion>
</AccordionGroup>

### Rate Limiting

Protect your application from abuse with built-in rate limiting:

* **Automatic rate limiting** based on your plan
* **Configurable limits** for enterprise customers
* **Per-key tracking** to isolate abuse
* **Gradual backoff** with clear error messages
* **Rate limit headers** in API responses

```http theme={null}
HTTP/1.1 429 Too Many Requests
X-RateLimit-Limit: 1000
X-RateLimit-Remaining: 0
X-RateLimit-Reset: 1641052800
Retry-After: 60
```

## Infrastructure Security

### Multi-Tenant Isolation

Each organization's data is strictly isolated:

* **Logical isolation** with organization-scoped queries
* **Database-level row security** policies
* **Separate encryption keys** per tenant
* **Network segmentation** for sensitive workloads
* **No cross-tenant data access** by design

### Access Controls

Strict access controls at every layer:

* **Role-Based Access Control (RBAC)** for team members
* **Principle of least privilege** for all services
* **Multi-factor authentication (MFA)** required for dashboard access
* **IP allowlisting** available for enterprise plans
* **Session timeout** and automatic logout
* **Audit logging** of all access and changes

### Network Security

Comprehensive network security measures:

* **DDoS protection** at network edge
* **Web Application Firewall (WAF)** filtering malicious traffic
* **Private networking** for internal services
* **VPC isolation** preventing lateral movement
* **Intrusion detection systems (IDS)** monitoring traffic
* **Security groups** restricting service communication

### Vulnerability Management

Proactive vulnerability identification and remediation:

* **Automated security scanning** of all code
* **Dependency vulnerability monitoring** with automatic updates
* **Regular penetration testing** by third-party firms
* **Bug bounty program** rewarding security researchers
* **Quarterly security assessments**
* **Zero-day response protocols**

## Compliance & Certifications

### SOC 2 Type II (In Progress)

Transmit is working towards SOC 2 Type II certification, implementing controls for:

* **Security** - Protection against unauthorized access
* **Availability** - System uptime and reliability
* **Processing Integrity** - Complete and accurate processing
* **Confidentiality** - Protection of confidential information
* **Privacy** - Collection and handling of personal information

We are building our security controls and processes to meet SOC 2 Type II requirements and will undergo independent audit once ready.

### GDPR Compliance

Full compliance with EU General Data Protection Regulation:

* **Data Processing Agreements (DPA)** available
* **Right to be forgotten** - Delete user data on request
* **Data portability** - Export data in machine-readable format
* **Consent management** - Opt-in/opt-out tracking
* **Data breach notification** - 72-hour notification requirement
* **Data residency options** for EU customers

### CCPA Compliance

California Consumer Privacy Act compliance:

* **Consumer rights** to access and delete data
* **Do Not Sell** opt-out mechanisms
* **Transparent data practices** disclosure
* **Data minimization** principles applied

### HIPAA Compliance

For healthcare customers:

* **HIPAA-compliant infrastructure**
* **Encrypted PHI** (Protected Health Information)
* **Audit logging** of all PHI access
* **Access controls** and authentication
* **Data encryption** at rest and in transit

### Additional Standards

We follow industry-standard security practices and are working toward additional certifications as we scale.

## Data Privacy

### Data Collection

We only collect data necessary to provide our service:

**What we collect:**

* Email addresses and content (to send emails)
* Phone numbers and SMS content (to send SMS)
* Engagement data (opens, clicks) when tracking enabled
* API usage logs for debugging and billing
* Minimal metadata (timestamps, IDs)

**What we don't collect:**

* Personal information beyond what you send
* Browsing history or tracking outside our platform
* Third-party cookies or cross-site tracking
* Sensitive data unless explicitly sent by you

### Data Retention

Clear data retention policies:

* **Message content**: 30 days by default (configurable)
* **Analytics data**: 12 months
* **Audit logs**: 7 years (compliance requirement)
* **Backups**: 90 days with automatic deletion
* **Deleted data**: Permanently purged within 30 days

### Data Location

Control where your data is stored:

* **US region** (default) - Data centers in United States
* **EU region** - Data centers in European Union
* **APAC region** - Data centers in Asia-Pacific
* **Data sovereignty** - Data never leaves selected region

## Webhook Security

### Signature Verification

All webhooks are signed with HMAC-SHA256:

```typescript theme={null}
import crypto from 'crypto';

function verifyWebhookSignature(
  payload: string,
  signature: string,
  secret: string
): boolean {
  const expectedSignature = crypto
    .createHmac('sha256', secret)
    .update(payload)
    .digest('hex');

  return crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(expectedSignature)
  );
}

app.post('/webhooks/transmit', (req, res) => {
  const signature = req.headers['x-transmit-signature'];
  const secret = process.env.TRANSMIT_WEBHOOK_SECRET;

  if (!verifyWebhookSignature(JSON.stringify(req.body), signature, secret)) {
    return res.status(401).send('Invalid signature');
  }

  // Process webhook...
  res.status(200).send('OK');
});
```

### Webhook Best Practices

<CardGroup cols={2}>
  <Card title="Always Verify Signatures" icon="shield-check">
    Never process webhooks without signature verification
  </Card>

  <Card title="Use HTTPS Endpoints" icon="lock">
    Webhook URLs must use HTTPS, never HTTP
  </Card>

  <Card title="Validate Payload Schema" icon="check">
    Verify payload structure matches expected format
  </Card>

  <Card title="Implement Replay Protection" icon="clock">
    Check timestamp and reject old webhooks
  </Card>
</CardGroup>

## Incident Response

### Security Incident Protocol

In the event of a security incident:

1. **Detection** - Automated monitoring alerts security team
2. **Assessment** - Immediate severity evaluation
3. **Containment** - Isolate affected systems
4. **Notification** - Inform affected customers within 24 hours
5. **Remediation** - Fix vulnerability and deploy patches
6. **Review** - Post-mortem analysis and improvements

### Data Breach Response

If data is compromised:

* **Immediate notification** to affected customers
* **Regulatory notification** within required timeframes (72h for GDPR)
* **Free credit monitoring** for affected individuals
* **Transparent communication** about scope and impact
* **Corrective action plan** publicly shared

## Security for Developers

### Secure Coding Practices

We follow security best practices in development:

* **Input validation** on all API parameters
* **Output encoding** to prevent injection attacks
* **Parameterized queries** to prevent SQL injection
* **Content Security Policy (CSP)** headers
* **CSRF protection** on all state-changing operations
* **Regular security training** for all engineers

### Third-Party Security

Careful vetting of third-party services:

* **Security questionnaires** for all vendors
* **Regular vendor reviews** and audits
* **Contractual security requirements**
* **Minimal data sharing** with third parties
* **Vendor security incident monitoring**

## Reporting Security Issues

We take security seriously and welcome responsible disclosure:

**Contact:** [security@transmit.dev](mailto:security@transmit.dev)

**Responsible Disclosure Program:**

1. Email [security@transmit.dev](mailto:security@transmit.dev) with details
2. Allow 90 days for remediation before public disclosure
3. Receive acknowledgment within 24 hours
4. Coordinated disclosure timeline agreed upon
5. Recognition in our security hall of fame (optional)

**Bug Bounty:** We offer rewards for critical vulnerabilities

<Warning>
  Please do not test vulnerabilities on production systems. Contact us for a safe testing environment.
</Warning>

## Security Checklist for Customers

Use this checklist to ensure you're following security best practices:

<AccordionGroup>
  <Accordion title="✅ API Key Security" icon="key">
    * [ ] Store API keys in environment variables
    * [ ] Never commit keys to version control
    * [ ] Use different keys per environment
    * [ ] Rotate keys every 90 days
    * [ ] Monitor key usage in dashboard
    * [ ] Revoke unused or compromised keys immediately
  </Accordion>

  <Accordion title="✅ Data Protection" icon="database">
    * [ ] Only send necessary data to Transmit
    * [ ] Sanitize user input before sending
    * [ ] Enable encryption for sensitive content
    * [ ] Configure appropriate data retention periods
    * [ ] Regularly audit data being sent
  </Accordion>

  <Accordion title="✅ Webhook Security" icon="webhook">
    * [ ] Use HTTPS endpoints only
    * [ ] Always verify webhook signatures
    * [ ] Validate payload structure
    * [ ] Implement replay attack protection
    * [ ] Rate limit webhook processing
    * [ ] Log all webhook events
  </Accordion>

  <Accordion title="✅ Access Control" icon="users">
    * [ ] Enable MFA for all team members
    * [ ] Use role-based access control
    * [ ] Regularly review team member access
    * [ ] Remove access for departed team members
    * [ ] Audit access logs monthly
  </Accordion>

  <Accordion title="✅ Monitoring" icon="chart-line">
    * [ ] Set up alerts for unusual activity
    * [ ] Monitor API error rates
    * [ ] Track authentication failures
    * [ ] Review bounce and complaint rates
    * [ ] Check for data exfiltration patterns
  </Accordion>
</AccordionGroup>

## Questions?

Our security team is here to help:

<CardGroup cols={2}>
  <Card title="Security Documentation" href="/docs/authentication" icon="book">
    Authentication and API security
  </Card>

  <Card title="Compliance Portal" href="https://trust.transmit.dev" icon="shield">
    Certifications and compliance docs
  </Card>

  <Card title="Security Contact" href="mailto:security@transmit.dev" icon="envelope">
    Report vulnerabilities or ask questions
  </Card>

  <Card title="Enterprise Security" href="https://transmit.dev/enterprise" icon="building">
    Advanced security features for enterprises
  </Card>
</CardGroup>