TLS Check inspects which TLS/SSL protocol versions a server supports. It probes TLS 1.0 through 1.3, reports which are negotiable, and derives a security verdict — the highest supported version, whether deprecated protocols are still exposed, and a composite risk score.
Try it — live request, no key required
No key required to try it. Get a key to use it in your app.
{
"status": "ok",
"error": null,
"data": {
// TLS Checker response payload
}
}
About the TLS Checker API
TLS Check connects to the provided domain and port and runs a TLS handshake for each protocol version to determine which are supported. It identifies the highest negotiable version (like TLS 1.2/1.3), flags whether deprecated TLS 1.0/1.1 remain exposed, and returns a composite risk score summarizing the server's protocol security.
Ways to call it
One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.
- JSON
- Default REST response
- XML
- Markup format
- YAML
- Human-readable
- CSV
- Tabular export
- GraphQL
- Query language
- MCP
- For AI agents
Other ways to use TLS Checker
Same data, same APIVerve account, same credit balance — one key works on all of them.
What does the TLS Checker API do?
How do I authenticate TLS Checker API requests?
How much does the TLS Checker API cost?
How fast is the TLS Checker API?
What response formats does the TLS Checker API support?
What HTTP method does the TLS Checker API use?
Request parameters — GET /v1/tlscheck
Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.
Required
| Parameter | Type | Example | Description |
|---|---|---|---|
domainRequired | string | amazon.com | The domain to check the TLS/SSL configuration for domain |
Optional
| Parameter | Type | Example | Description |
|---|---|---|---|
portOptional | integer | 443 | The port to connect to (usually 443 for HTTPS) default 443 · range 1-65535 |
curl "https://api.apiverve.com/v1/tlscheck?domain=amazon.com&port=443" \
-H "x-api-key: YOUR_API_KEY"Authentication
Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.
| Header | When | Value |
|---|---|---|
x-api-keyRequired | Every request | Your API key. Header names are case-insensitive, so X-API-Key is the same header. |
AuthorizationAlternate | Instead of the above | Bearer <key> — for clients that only expose bearer auth. Resolves to the same account and the same billing. |
A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.
Response — GET /v1/tlscheck
Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.
{
"status": "ok",
"error": null,
"data": {
"domain": "amazon.com",
"tlsVersions": {
"TLSv1": false,
"TLSv1.1": false,
"TLSv1.2": true,
"TLSv1.3": true
},
"highestVersion": "TLSv1.3",
"hasDeprecatedTLS": false,
"isSecure": true,
"riskScore": 0,
"riskLevel": "low"
}
}
Response fields
Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.
| Field | Type | Example | Description |
|---|---|---|---|
domain | string | "amazon.com" | Domain name that was checked for TLS configuration |
tlsVersions | object | {...} | |
TLSv1 | boolean | false | Whether TLS 1.0 protocol is supported by server |
1 | boolean | false | Whether TLS 1.1 protocol is supported by server |
2 | boolean | true | Whether TLS 1.2 protocol is supported by server |
3 | boolean | true | Whether TLS 1.3 protocol is supported by server |
highestVersion | string | "TLSv1.3" | The highest TLS version the server supports (e.g. TLSv1.3), or null if none were negotiable |
hasDeprecatedTLSPremium | boolean | false | Whether the server still supports deprecated TLS 1.0 or 1.1, which are insecure and disallowed by PCI-DSS |
isSecurePremium | boolean | true | Whether the server supports a modern TLS version (1.2/1.3) and does not expose any deprecated version |
riskScorePremium | number | 0 | Composite 0-100 risk score based on missing modern TLS and exposure of deprecated protocols (higher is riskier) |
riskLevelPremium | string | "low" | Risk band derived from the score: low, medium or high |
Response headers
Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.
| Header | What it carries |
|---|---|
x-api-remaining-credits | Credits left in the current cycle |
x-api-credits-used | Credits spent in the current cycle |
x-api-max-credits | The allowance for the cycle |
x-api-version | Version of the endpoint that answered |
Errors
Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.
| Status | Meaning | What to do |
|---|---|---|
400 | Input was rejected | Read error; it names the parameter that has to change. |
401 | Key missing or invalid | Check the header name and the key value. |
403 | Key valid, but not permitted here | A key restriction or an IP allow-list — never a bad key. |
429 | Rate limited, or out of credits | Read error to tell them apart, then back off or top up. |
What a call costs — 2 credits per call
Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.
| Plan | Per month | Credits | TLS Checker calls | Per 1,000 calls |
|---|---|---|---|---|
| Free | Free | 200 | 100 | Free |
| Starter | $29.99 | 200,000 | 100,000 | $0.30 |
| Pro | $99.99 | 1,000,000 | 500,000 | $0.20 |
| Mega | $299.99 | 4,000,000 | 2,000,000 | $0.15 |
Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.
Call it from cURL — GET /v1/tlscheck
No SDK to install — this is a plain HTTPS call to /v1/tlscheck with your key in the x-api-key header. Swap in a real key and it runs as-is.
curl "https://api.apiverve.com/v1/tlscheck" \
-H "x-api-key: YOUR_API_KEY"Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Node.js — GET /v1/tlscheck
Install the Node.js SDK, then call the TLS Checker API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
npm install @apiverve/tlscheckconst res = await fetch("https://api.apiverve.com/v1/tlscheck", {
headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Python — GET /v1/tlscheck
No SDK to install — this is a plain HTTPS call to /v1/tlscheck with your key in the x-api-key header. Swap in a real key and it runs as-is.
import requests
res = requests.get(
"https://api.apiverve.com/v1/tlscheck",
headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from C# / .NET — GET /v1/tlscheck
Install the C# / .NET SDK, then call the TLS Checker API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
dotnet add package APIVerve.API.TLSCheckerusing var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");
var json = await client.GetStringAsync("https://api.apiverve.com/v1/tlscheck");
Console.WriteLine(json);Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Go — GET /v1/tlscheck
No SDK to install — this is a plain HTTPS call to /v1/tlscheck with your key in the x-api-key header. Swap in a real key and it runs as-is.
req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/tlscheck", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from PHP — GET /v1/tlscheck
No SDK to install — this is a plain HTTPS call to /v1/tlscheck with your key in the x-api-key header. Swap in a real key and it runs as-is.
$ch = curl_init("https://api.apiverve.com/v1/tlscheck");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);
$response = curl_exec($ch);
echo $response;Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Ruby — GET /v1/tlscheck
No SDK to install — this is a plain HTTPS call to /v1/tlscheck with your key in the x-api-key header. Swap in a real key and it runs as-is.
require "net/http"
uri = URI("https://api.apiverve.com/v1/tlscheck")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"
res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.bodyResources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Zero-code embed — one snippet, no backend
Drop an interactive TLS Checker form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.
Changelog — TLS Checker API
Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.
Entries are picked up from dated catalog snapshots, so the first one appears after the next snapshot that moves something. A period where nothing changed produces no entry — silence is a valid changelog for the TLS Checker API.
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