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TLS Version

free
GET/v1/domain/tls-version

Verifies TLS connectivity for a domain and confirms support for modern TLS versions (1.2+). Note: Cloudflare Workers negotiate TLS 1.2 or 1.3 automatically; individual version testing requires dedicated tools like testssl.sh or SSL Labs.

What It Does

Performs a TLS handshake with the domain to verify connectivity. A successful connection confirms the server supports at minimum TLS 1.2. TLS 1.3 support may also be present but cannot be independently confirmed from this environment. For precise per-version enumeration, use testssl.sh, nmap, or Qualys SSL Labs.

Why It's Useful

TLS version support directly impacts security posture. PCI DSS 4.0.1 (current version) and NIST SP 800-52r2 require TLS 1.2 as a minimum, and HIPAA follows similar guidance. This endpoint helps verify compliance and identify servers needing protocol updates.

Use Cases

Compliance Officer

Security Compliance Audit

Verify all public-facing servers have disabled TLS 1.0 and 1.1 as required by PCI DSS 4.0.

Maintain compliance by identifying servers with deprecated TLS versions.

Penetration Tester

Security Assessment

Identify weak TLS configurations during security assessments.

Document TLS misconfigurations for remediation recommendations.

DevOps Engineer

Infrastructure Hardening

Verify TLS configuration after hardening load balancers or web servers.

Confirm TLS hardening was applied correctly across infrastructure.

Parameters

NameTypeRequiredDescription
domainstringRequiredThe domain to check TLS version support forExample: example.com
portnumberOptionalPort to connect to (default: 443)Example: 443

Response Fields

FieldTypeDescription
domainstringThe queried domain
portnumberThe port used for connection
supportedVersionsarrayTLS versions confirmed as supported (at minimum TLS 1.2)
preferredVersionstring | nullNegotiated TLS version (from Cloudflare metadata, or null if unavailable)
negotiatedCipherstring | nullNegotiated cipher suite (from Cloudflare metadata, or null if unavailable)
deprecatedVersionsarrayDeprecated TLS versions detected (empty — per-version testing not available)
recommendationsarraySecurity improvement suggestions

Code Examples

cURL
curl "https://api.edgedns.dev/v1/domain/tls-version" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d "domain=example.com"
JavaScript
const response = await fetch(
  'https://api.edgedns.dev/v1/domain/tls-version?domain=example.com',
  {
    headers: {
      'Authorization': 'Bearer YOUR_API_KEY'
    }
  }
);

const data = await response.json();
console.log(data);
Python
import requests

response = requests.get(
    'https://api.edgedns.dev/v1/domain/tls-version',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    params={
    'domain': 'example.com'
    }
)

data = response.json()
print(data)

Read the full TLS Version guide

Why it matters, real-world use cases, parameters, response fields, and how to call it from Claude, ChatGPT, or Gemini via MCP.

Read the guide →

Related Endpoints

External References

Learn more about the standards and protocols behind this endpoint.

Try This Endpoint

Test the TLS Version endpoint live in the playground.