CSR Parser API POST

CSR Parser extracts and analyzes information from Certificate Signing Requests (CSRs), providing detailed subject information, public key details, and fingerprints.

Try it — live request, no key required

Request

POSTapi.apiverve.com/v1/csrparser

Verification

Format

No key required to try it. Get a key to use it in your app.

200 OK

{
  "status": "ok",
  "error": null,
  "data": {
    // CSR Parser response payload
  }
}

About the CSR Parser API

Perfect for SSL/TLS certificate management systems, security tools, and automated certificate workflows that need to validate and process CSRs.

What people use it for

CSR Validation: Validate Certificate Signing Requests before certificate issuance to ensure proper formatting and required fields
Information Extraction: Extract subject information, public key details, and signature algorithms from certificate requests for processing
Certificate Management: Build certificate management systems with automated CSR parsing and validation capabilities
SSL/TLS Automation: Automate SSL/TLS certificate workflows including CSR generation validation, certificate issuance, and renewal processes

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

View all integrations →

Other ways to use CSR Parser

Same data, same APIVerve account, same credit balance — one key works on all of them.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.on VerveKit

Questions.

Common questions about the CSR Parser API.

Read the docs →

What does the CSR Parser API do?

CSR Parser extracts and analyzes information from Certificate Signing Requests (CSRs), providing detailed subject information, public key details, and fingerprints.

How do I authenticate CSR Parser API requests?

Pass your API key in the x-api-key header over HTTPS. One key works across all 300+ APIVerve APIs — there are no per-endpoint credentials.

How much does the CSR Parser API cost?

Each call spends 2 credits from your shared pool. The free tier includes 200 credits every month, and paid plans add more headroom.

How fast is the CSR Parser API?

Response time depends on the endpoint — the p50 through p99 latency for this API is published on this page. Requests are served over HTTPS through a global edge network.

What response formats does the CSR Parser API support?

JSON by default, plus XML and YAML via the format parameter. GraphQL and an MCP interface for AI agents are available across the catalog.

What HTTP method does the CSR Parser API use?

POST over HTTPS, following standard REST conventions with a consistent { status, error, data } response envelope.

Request parameters — POST /v1/csrparser

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
`csr`Required	string	-----BEGIN CERTIFICATE REQUEST----- MIICvDCCAaQCAQAwdzELMAkGA1UEBhMCVVMxEzARBgNVBAgMCkNhbGlmb3JuaWEx FjAUBgNVBAcMDVNhbiBGcmFuY2lzY28xEzARBgNVBAoMCkV4YW1wbGUgQ28xEDAO BgNVBAsMB0RldlRlYW0xFDASBgNVBAMMC2V4YW1wbGUuY29tMIIBIjANBgkqhkiG 9w0BAQEFAAOCAQ8AMIIBCgKCAQEAjd/RepiCLQ5/HfKynijcPdiwygrSgxQeTKPo T/WiEaRTaUToW9uDUeiIHK83Tgn2+TIONpMoLJRNG+zslpHybWhVVWNlamkrlRwP XFQJzsxDN5+TQugILatLsp680SgMNyyPtDIpT3niiNuQ4NFepQLvQTbjXgj1celb U86CCeJzYengTF0ZE9Ra+/SsRTA+oy0fNLChNMc2DBaybccxwV2rNWvlvPdhfB7M sel3sw/x2hsbWoYC/kudzYmoDPZKX+XOhCkFwUgwib8V4hbjVLcOYsPBJcROYpRh 9d5g7xdRlbF1I7dHsCRKnsvkIONtwKQmJ2v/UPqYahjtm2TPUQIDAQABoAAwDQYJ KoZIhvcNAQELBQADggEBAFEHOsN2SkB3qFBMk9JR5IDoh8rSUKj/310DOwilOQm+ 5lAwRfcFMYCl9yf4IV+XPPfvT3ahzUFfi8Fc98CDeIxAhEwtuZFlE7LA5+/F4HXM H3gzqTFwOZq+Wa2m029/BvcyII830h4Z+gU68R52px7O7wYSbAR/n7t1fh2bxzmW KqqjrvCpHoMVpgcm9y2bYTj+HLxgX4/uADFvotQppOWZi0ctam+if3Kqb3Kd2MFD vVHZp9NwEoqNPxmFEzcyOk2y1PYhhRja7rjdC6bdAqj6JRt+WSzStvgx7aEsxBQj rJCMi+GypGf9xQUfCJBhTDQVQ3fmCKTfddDeeVbJBrA= -----END CERTIFICATE REQUEST-----	The PEM-formatted Certificate Signing Request to parse

Example request

curl -X POST "https://api.apiverve.com/v1/csrparser" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"csr":"-----BEGIN CERTIFICATE REQUEST-----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\nrJCMi+GypGf9xQUfCJBhTDQVQ3fmCKTfddDeeVbJBrA=\n-----END CERTIFICATE REQUEST-----"}'

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-key`Required	Every request	Your API key. Header names are case-insensitive, so `X-API-Key` is the same header.
`Authorization`Alternate	Instead of the above	`Bearer <key>` — for clients that only expose bearer auth. Resolves to the same account and the same billing.
`content-type`Required	POST body	`application/json`

401 is the only auth verdict

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/csrparser

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.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "version": "v1",
    "subject": {
      "common_name": "example.com",
      "organization": "Example Co",
      "organizational_unit": "DevTeam",
      "locality": "San Francisco",
      "state": "California",
      "country": "US",
      "email": null
    },
    "public_key": {
      "algorithm": "RSA",
      "size_bits": 2048,
      "exponent": 65537
    },
    "signature_algorithm": "SHA256withRSA",
    "extensions": [],
    "fingerprints": {
      "sha1": "05:E5:65:28:8A:47:01:D3:05:EA:3B:3F:F5:DC:C7:42:BF:06:E2:5F",
      "sha256": "E0:0B:C1:59:A3:9E:F9:96:13:7B:CE:98:BC:8F:A1:49:62:4D:2E:CF:85:D5:36:2C:DD:46:9E:96:CF:92:A3:AF",
      "md5": "27:C7:EC:94:73:34:E3:B7:3F:F6:FD:3E:0A:81:EA:3D"
    },
    "pem": "-----BEGIN CERTIFICATE REQUEST-----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\nrJCMi+GypGf9xQUfCJBhTDQVQ3fmCKTfddDeeVbJBrA=\n-----END CERTIFICATE REQUEST-----",
    "size_bytes": 704,
    "format": "PEM",
    "is_valid": true,
    "security_assessment": {
      "is_weak_key": false,
      "is_deprecated_signature": false,
      "key_strength": "acceptable"
    }
  }
}

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
`version`	string	`"v1"`	CSR format version identifier
`subject`	object	`{...}`
`common_name`	string	`"example.com"`	Common name from CSR subject distinguished name
`organization`	string	`"Example Co"`	Organization name from CSR subject field
`organizational_unit`	string	`"DevTeam"`	Organizational unit from CSR subject
`locality`	string	`"San Francisco"`	Locality or city from CSR subject
`state`	string	`"California"`	State or province from CSR subject
`country`	string	`"US"`	Country code from CSR subject
`email`	object	`null`	Email address from CSR subject
`public_key`	object	`{...}`
`algorithm`	string	`"RSA"`	Public key algorithm type used in CSR
`size_bits`	number	`2048`	Public key size in bits
`exponent`Premium	number	`65537`	RSA public exponent value
`signature_algorithm`Premium	string	`"SHA256withRSA"`	Algorithm used to sign the CSR
`extensions`Premium	array	`[]`	X.509 extensions included in CSR
`fingerprints`Premium	object	`{...}`	CSR fingerprints in various hash formats
`sha1`Premium	string	`"05:E5:65:28:8A:47:01:D3:05:EA:3B:3F:F5:DC:C7:42:BF:06:E2:5F"`	SHA1 fingerprint of CSR in colon format
`sha256`Premium	string	`"E0:0B:C1:59:A3:9E:F9:96:13:7B:CE:98:BC:8F:A1:49:62:4D:2E:CF:85:D5:36:2C:DD:46:9E:96:CF:92:A3:AF"`	SHA256 fingerprint of CSR in colon format
`md5`Premium	string	`"27:C7:EC:94:73:34:E3:B7:3F:F6:FD:3E:0A:81:EA:3D"`	MD5 fingerprint of CSR in colon format
`pem`	string	`"-----BEGIN CERTIFICATE REQUEST----- MIICvDCCAaQCAQAwdzELMAkGA1UEBhMCVVMxEzARBgNVBAgMCkNhbGlmb3JuaWEx FjAUBgNVBAcMDVNhbiBGcmFuY2lzY28xEzARBg…`	PEM-encoded CSR data
`size_bytes`	number	`704`	CSR size in bytes
`format`	string	`"PEM"`	Certificate encoding format type
`is_valid`	boolean	`true`	Whether CSR format is valid
`security_assessment`Premium	object	`{...}`	Derived security posture of the request: weak-key detection (RSA < 2048 / EC < 256), deprecated signature hash (SHA1/MD5), and an overall key strength rating
`is_weak_key`Premium	boolean	`false`
`is_deprecated_signature`Premium	boolean	`false`
`key_strength`Premium	string	`"acceptable"`

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	CSR Parser 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.

Compare all pricing tiers →

Call it from cURL — POST /v1/csrparser

No SDK to install — this is a plain HTTPS call to /v1/csrparser with your key in the x-api-key header. Swap in a real key and it runs as-is.

cURL

1
2

curl "https://api.apiverve.com/v1/csrparser" \
  -H "x-api-key: YOUR_API_KEY"

Resources

GitHubapiverve/csrparser-apiSource, issues and the examples this page is built from.ReferenceCSR Parser API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/csrparsernpm APIVerve.API.CSRParserNuGet

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/csrparser

Install the Node.js SDK, then call the CSR Parser API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — npm

npm install @apiverve/csrparser

Node.js

const res = await fetch("https://api.apiverve.com/v1/csrparser", {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);

Resources

npm@apiverve/csrparserThe published Node.js client, versioned and signed.GitHubapiverve/csrparser-apiSource, issues and the examples this page is built from.ReferenceCSR Parser API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

APIVerve.API.CSRParserNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Python — POST /v1/csrparser

No SDK to install — this is a plain HTTPS call to /v1/csrparser with your key in the x-api-key header. Swap in a real key and it runs as-is.

Python

import requests

res = requests.get(
    "https://api.apiverve.com/v1/csrparser",
    headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])

Resources

Also published for

@apiverve/csrparsernpm APIVerve.API.CSRParserNuGet

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/csrparser

Install the C# / .NET SDK, then call the CSR Parser API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — NuGet

dotnet add package APIVerve.API.CSRParser

C# / .NET

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

var json = await client.GetStringAsync("https://api.apiverve.com/v1/csrparser");
Console.WriteLine(json);

Resources

NuGetAPIVerve.API.CSRParserThe published C# / .NET client, versioned and signed.GitHubapiverve/csrparser-apiSource, issues and the examples this page is built from.ReferenceCSR Parser API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/csrparsernpm

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Go — POST /v1/csrparser

No SDK to install — this is a plain HTTPS call to /v1/csrparser 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/csrparser", 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

@apiverve/csrparsernpm APIVerve.API.CSRParserNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from PHP — POST /v1/csrparser

No SDK to install — this is a plain HTTPS call to /v1/csrparser with your key in the x-api-key header. Swap in a real key and it runs as-is.

PHP

$ch = curl_init("https://api.apiverve.com/v1/csrparser");
curl_setopt($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

@apiverve/csrparsernpm APIVerve.API.CSRParserNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Ruby — POST /v1/csrparser

No SDK to install — this is a plain HTTPS call to /v1/csrparser with your key in the x-api-key header. Swap in a real key and it runs as-is.

Ruby

require "net/http"

uri = URI("https://api.apiverve.com/v1/csrparser")
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.body

Resources

Also published for

@apiverve/csrparsernpm APIVerve.API.CSRParserNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

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CSR Parser API POST

Try it — live request, no key required

About the CSR Parser API

What people use it for

Ways to call it

Other ways to use CSR Parser

Questions.

Request parameters — POST /v1/csrparser

Required

Authentication

Response — POST /v1/csrparser

Response fields

Response headers

Errors

What a call costs — 2 credits per call

Call it from cURL — POST /v1/csrparser

Resources

Also published for

Call it from Node.js — POST /v1/csrparser

Resources

Also published for

Call it from Python — POST /v1/csrparser

Resources

Also published for

Call it from C# / .NET — POST /v1/csrparser

Resources

Also published for

Call it from Go — POST /v1/csrparser

Resources

Also published for

Call it from PHP — POST /v1/csrparser

Resources

Also published for

Call it from Ruby — POST /v1/csrparser

Resources

Also published for

Zero-code embed — one snippet, no backend

Changelog — CSR Parser API

Security

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