Posthook

Posthook is a term used in software development to describe a callback or hook that runs after a specified action has completed. It is typically contrasted with prehooks, which execute before the action. Posthooks are used to perform tasks that should occur only after the main operation finishes, such as logging, auditing, sending notifications, updating related systems, or cleanup.

Posthooks are implemented in various ways, including as event listeners, observers, middleware, or callback registries. They can be executed synchronously or asynchronously and may run within the same transactional context or after a commit, depending on the framework. When sensitive to success, posthooks are often designed to trigger only on successful completion of the primary action, though some systems allow posthooks to run regardless and handle failure accordingly.

Common use cases include:

- Sending a confirmation email after a user account is created

- Synchronizing data with external services after a database write

- Generating audit trails or activity logs

- Enqueuing follow-up tasks once a job finishes

Design considerations for posthooks include the order of execution, potential for reentrancy, idempotence to handle retries safely, performance impact, and error handling. Since posthooks can affect user-perceived latency or system state, they are often chosen to be asynchronous or decoupled from the main request path when possible.

In summary, a posthook extends a system’s behavior by enabling actions to occur after the primary operation, improving modularity while requiring careful management of timing and failure modes.