How can I get troubleshooting support for an unexplainable problem with the API?

If you're stuck and can't work out why a problem is occurring with the HIBP API, when you submit a support ticket it's important to provide information in a fashion such that the issue can be replicated. Often, people are using third party apps or scripts which we can't support so the problem needs to be boiled down to the raw HTTP request. The easiest way to do this is to send either a cURL command or a Powershell command in the ticket with the API key redacted, and include the full response (both headers and body) when run locally in your environment.

With cURL

curl --header "hibp-api-key: [redacted]" -i https://haveibeenpwned.com/api/v3/breachedaccount/account-exists%40hibp-integration-tests.com

And the output:

  HTTP/1.1 200 OK
  Date: Fri, 20 Jan 2023 21:17:29 GMT
  Content-Type: application/json; charset=utf-8
  Transfer-Encoding: chunked
  Connection: keep-alive
  CF-Ray: 78cad64f8d3f32a1-BNE
  Cache-Control: no-cache
  Expires: -1
  Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
  Vary: Accept-Encoding
  CF-Cache-Status: DYNAMIC
  Pragma: no-cache
  X-Content-Type-Options: nosniff
  Set-Cookie: __cf_bm=zjzU.T7AHUCGMWRY0_rTNMwobzzkzpRzsvwS2HcPl1I-1674249449-0-AfVtZ20x1qabk41TeAzexU8Dtsq1a3YALUOZNMAS+FmvJ3NlehcpwRew1X/OXbCG3W63mJoAZpcyWUNYckYGkR0=;
  path=/; expires=Fri, 20-Jan-23 21:47:29 GMT; domain=.haveibeenpwned.com; HttpOnly;
  Secure; SameSite=None
  Server: cloudflare

[{"Name":"Adobe"}]

With Powershell

Invoke-WebRequest -Headers @{'hibp-api-key' = '[redacted]'} -URI https://haveibeenpwned.com/api/v3/breachedaccount/account-exists%40hibp-integration-tests.com<

And the output:

  StatusCode : 200
  StatusDescription : OK
  Content : [{"Name":"Adobe"}]
  RawContent : HTTP/1.1 200 OK
  Transfer-Encoding: chunked
  Connection: keep-alive
  CF-Ray: 78cae607ebcae9b7-BNE
  Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
  Vary: Accept-Encoding
  CF-Ca...
  Forms : {}
  Headers : {[Transfer-Encoding, chunked], [Connection, keep-alive], [CF-Ray, 78cae607ebcae9b7-BNE],
  [Strict-Transport-Security, max-age=31536000; includeSubDomains; preload]...}
  Images : {}
  InputFields : {}
  Links : {}
  ParsedHtml : mshtml.HTMLDocumentClass
  RawContentLength : 18