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Package detail

nestjs-cls

Papooch1.6mMIT6.0.1TypeScript support: included

A continuation-local storage module compatible with NestJS's dependency injection.

nest, nestjs, cls, continuation-local-storage, als, AsyncLocalStorage, async_hooks, request context, async context

readme

NestJS CLS (Async Context)

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, ...)

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.

Documentation

➡️ Go to the documentation website 📖

Contributing

Contributing to a community project is always welcome, please see the Contributing guide :)