Inject context into functions

[Grégoire (verdie-g)]

I'd like to be able to inject context, such as the user id associated to the current HTTP request. Is that possible with SK .NET?

I could try to do that by adding a userId parameter in my function and pass it in the prompt but that wouldn't be as reliable as fetching it from the context.

[Itay (itayfisz)]

You could use the Data dictionary in the Kernel object to add any custom data, and then it can be passed to any KernelFunction.

Something like this:

var clonedKernel = kernel.Clone();

clonedKernel.Data["userId"] = "123";

// Use the clonedKernel, for example using IChatCompletionService
var completionService = clonedKernel.GetRequiredService<IChatCompletionService>();

...

And in any plugin:

[KernelFunction]
public Task DoSomethingAsync(Kernel kernel, ...)
{
  var userId = kernel.Data["userId"]
  ...
}

[Grégoire (verdie-g)]

Thanks! Is a Kernel a light-weight object that can be cloned for each request?

[Itay (itayfisz)]

From my understanding - yes.
Disclaimer: I'm not sure if this is indeed the best practice. There might be some more standardized way, but I couldn't find any. (I think you can achieve something similar by leveraging the KernelArguments, which can also be injected).
Btw, notice this is a shallow copy of the dictionary.

[DmitryLukyanovCh]

I'm curious about how recommended this approach if kernel is registered as singleton

[Gyanu Mayank (gyanu2507)]

Kernel.Data is fine per request. It is a bad place if the kernel is a singleton.

kernel.Clone() then cloned.Data["userId"] = ... for that HTTP call, as Itay (@itayfisz) wrote. Do not write userId onto the shared instance. Concurrent requests will leak ids into each other's plugins.

Other options that don't fight DI:

• KernelArguments on the invoke (only if the plugin method takes that argument)
• IHttpContextAccessor inside the plugin and read User / a header there
• a scoped service registered with the kernel's service provider, resolved from the plugin

I would not put request-scoped data on a singleton kernel even with a lock. Clone or scope it.