A WebHook is a notification mechanism used by the AP system to notify the recipient when a document addressed to them is received. It is implemented as an HTTP POST request triggered by the AP system upon receipt of a document for the respective customer.

WebHook URL is stored in table SUBJECT and column WEBHOOK_URL. The WebHook is secured with a token that the AP system includes in the HTTP header X-PEPPOL-WEBHOOK-SECRET when invoking the WebHook. Token is stored in table SUBJECT and column SECRET_WEBHOOK. When the WebHook is invoked, the recipient can verify whether the token value matches the expected one. The body of the HTTP request contains the ID of the received document.

Example of WebHook call:

POST https://peppol.eso9.cz/PeppolWebHookExample/

Request Headers:
  POST /PeppolWebHookExample/ HTTP/1.1
  X-PEPPOL-WEBHOOK-SECRET: abcdef123456
  Content-Type: application/json
  User-Agent: PostmanRuntime/7.48.0
  Accept: */*
  Cache-Control: no-cache
  Host: peppol.eso9.cz
  Accept-Encoding: gzip, deflate, br
  Connection: keep-alive
  Content-Length: 6

Request Body:
  123456
 
HTTP/1.1 200 OK

Response Headers:
  Cache-Control: private
  Content-Type: application/json; charset=utf-8
  Server: Microsoft-IIS/10.0
  X-AspNet-Version: 4.0.30319
  X-Powered-By: ASP.NET
  Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
  Date: Tue, 07 Oct 2025 08:50:15 GMT
  Content-Length: 20

Response Body: 
  {"status":"success"}