HMAC Generator creates Hash-based Message Authentication Codes for data integrity and authentication. Supports SHA-256, SHA-384, SHA-512, SHA-1, and MD5 algorithms.
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": {
// HMAC Generator response payload
}
}
About the HMAC Generator API
Returns the HMAC signature in hex or base64 encoding. Use for signing API requests, validating webhooks, or any scenario requiring message authentication.
What people use it for
- API Authentication
- Sign API requests to prove authenticity
- Webhook Verification
- Validate incoming webhooks from services like Stripe, GitHub
- Data Integrity
- Ensure messages haven't been tampered with
- JWT Signing
- Generate signatures for JSON Web Tokens
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 HMAC Generator
Same data, same APIVerve account, same credit balance — one key works on all of them.
What does the HMAC Generator API do?
How do I authenticate HMAC Generator API requests?
How much does the HMAC Generator API cost?
How fast is the HMAC Generator API?
What response formats does the HMAC Generator API support?
What HTTP method does the HMAC Generator API use?
Request parameters — POST /v1/hmac
Sent as JSON in the request body. 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 |
|---|---|---|---|
messageRequired | string | Hello World | The message to sign |
secretRequired | string | my-secret-key | The secret key for HMAC generation |
Optional
| Parameter | Type | Example | Description |
|---|---|---|---|
algorithmOptional | string | sha256 | Hash algorithm to usesha256sha384sha512sha1md5default sha256 |
encodingOptional | string | hex | Output encoding formathexbase64default hex |
curl -X POST "https://api.apiverve.com/v1/hmac" \
-H "x-api-key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"message":"Hello World","secret":"my-secret-key","algorithm":"sha256","encoding":"hex"}'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. |
content-typeRequired | POST body | application/json |
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 — POST /v1/hmac
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": {
"hmac": "2cd7c25025198d4458002ceb064ad37ccfbbe46650876d693f5e080bd954e449",
"algorithm": "sha256",
"encoding": "hex"
}
}
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 |
|---|---|---|---|
hmac | string | "2cd7c25025198d4458002ceb064ad37ccfbbe46650876d693f5e080bd954e449" | Generated HMAC signature in specified encoding format |
algorithm | string | "sha256" | Hash algorithm used for HMAC generation |
encoding | string | "hex" | Output encoding format applied to the signature |
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 | HMAC Generator 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 — POST /v1/hmac
No SDK to install — this is a plain HTTPS call to /v1/hmac 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/hmac" \
-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 — POST /v1/hmac
Install the Node.js SDK, then call the HMAC Generator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
npm install @apiverve/hmacconst res = await fetch("https://api.apiverve.com/v1/hmac", {
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 — POST /v1/hmac
No SDK to install — this is a plain HTTPS call to /v1/hmac 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/hmac",
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 — POST /v1/hmac
Install the C# / .NET SDK, then call the HMAC Generator 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.HMACGeneratorusing var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");
var json = await client.GetStringAsync("https://api.apiverve.com/v1/hmac");
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 — POST /v1/hmac
No SDK to install — this is a plain HTTPS call to /v1/hmac 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/hmac", 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 — POST /v1/hmac
No SDK to install — this is a plain HTTPS call to /v1/hmac with your key in the x-api-key header. Swap in a real key and it runs as-is.
$ch = curl_init("https://api.apiverve.com/v1/hmac");
curl_setopt($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 — POST /v1/hmac
No SDK to install — this is a plain HTTPS call to /v1/hmac 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/hmac")
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 HMAC Generator 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 — HMAC Generator 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 HMAC Generator API.
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