# Payment Event Tokens If you have a webhook endpoint on your web application and configured your Phenixio account settings accordingly (See previous section: [Webhooks](/for-developers/webhooks.md)) we will sent you event notifications when a payment event happens. ### Json Web Tokens (JWTs) For the convenience and security purposes we use industry standard JWTs. If you are not already familiar with JWTs, you can learn more about here: [jwt.io](https://jwt.io). They are really simply JSON messages with cryptographic signatures, providing secure communication between two parties. #### Tamper Proof JSON content is safe against tampering. If the content of the message is changed by an attacker, signature becomes invalid. Since the attacker does not have the private key to generate a valid signature, their attempt will fail. #### Public Key Cryptography Currently we use RS256 (RSA Signature with [SHA-256](https://en.wikipedia.org/wiki/SHA-256))�, it is an [asymmetric algorithm](https://en.wikipedia.org/wiki/Public-key_cryptography),� and it uses a public/private key pair: the identity provider has a private (secret) key used to generate the signature, and the consumer of the JWT gets a public key to validate the signature. This helps us avoid sharing the secret. Only the private key holder can generate valid signature for a given public key. But anyone with the public key can verify the token is indeed generated by the trusted party. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.phenixio.com/for-developers/event-tokens.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.