RAG component does not expose providerMetadata to usageHandler

[yantakus]

For example, Agent component with the following config:

export const titleAgent = new Agent(components.agent, {
  languageModel: "openai/gpt-4o-mini",
  usageHandler: async (ctx, args) => {
    const gateway = args.providerMetadata?.gateway;
    if (!gateway) {
      throw new Error("Missing providerMetadata.gateway");
    }
    const creditsSpent = costToCredits(gateway.cost);
    ...
  };
});

works just fine.

And RAG component with the same config (it only has an additional textEmbeddingModel: "openai/text-embedding-3-small") throws an error because args.providerMetadata is missing.

Please, add it, otherwise I have to calculate the cost myself. Not a big deal, but still would like not to hardcode input and output token cost.

[ianmacartney]

@yantakus I'm a bit confused - RAG doesn't have a usageHandler argument. Instead, usage is returned from various functions. Are you asking that a usageHandler is added?

[yantakus]

@ianmacartney Hm, I checked source code and you are right, usageHandler is missing in RAG component. Looks like my debugging conclusion was wrong and it was Agent component call where providerMetadata is sometimes missing. Will have a look once again later.

But in general, yes, it would be very convenient if both components (Agent and RAG) have the same usageHandler API and we could just reuse the same code. In my case I just reused the same defaultConfig between these two and intuitively expected it should just work :)

Thanks.

[ianmacartney]

Maybe it's the usageHandler callback for vector embeddings? That return value is unfortunately much more sparse - part of why RAG has a different mechanism. Feel free to check out the AI SDK responses for embedding text to see if what you want is even possible