# Macros `MESSAGE_RECEIVED_HOOK` - define function handler which receives message, e.g., issue or transfer token to user `MESSAGE_RECEIVED_FAILURE_HOOK` - define function handler which receives failed message, e.g., mark message as failed and add to failed message table `MESSAGE_RECEIPT_HOOK` - define function handler which receives receipt, e.g., return tokens to sender, transfer failed `MESSAGE_RECEIPT_FAILURE_HOOK` - define function handler which receives failed receipt, .e.g., mark receipt as failed and add to failed message table `LINK_INIT_METHODS` - defines methods for link --- # 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.liquidapps.io/liquidapps-documentation/introduction/dapp-network-resources/link-library/eosio-link/macros.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.