A continuation-local storage module compatible with NestJS' dependency injection based on AsyncLocalStorage.
Notice: The documentation has been moved to a dedicated website.
Continuation-local storage allows to store state and propagate it throughout callbacks and promise chains. It allows storing data throughout the lifetime of a web request or any other asynchronous duration. It is similar to thread-local storage in other languages.
Some common use cases that this library enables include:
- Tracking the Request ID and other metadata for logging purposes
- Keeping track of the user throughout the whole request
- Making the dynamic Tenant database connection available everywhere in multi-tenant apps
- Propagating the authentication level or role to restrict access to resources
- Seamlessly propagating database transaction across services without breaking encapsulation and isolation by explicitly passing it around (Now available with the Transactional plugin)
- Using "request" context in cases where actual REQUEST-scoped providers are not supported (passport strategies, cron controllers, websocket gateways, queue consumers, ...)
- Replace REQUEST-scoped providers with Proxy Providers.
Most of these are to some extent solvable using REQUEST-scoped providers or passing the context as a parameter, but these solutions are often clunky and come with a whole lot of other issues.
Contributing to a community project is always welcome, please see the Contributing guide :)