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Comment by jcgl | Hacker News Reader

The model only sees a stream of tokens, right? So how do you signal a change in authority (i.e. mark the transition between system and user prompt)? Because a stream of tokens inherently has no out-of-band signaling mechanism, you have to encode changes of authority in-band. And since the user can enter whatever they like in that band...

But maybe someone with a deeper understanding can describe how I'm wrong.

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When LLMs process tokens, each token is first converted to an embedding vector. (This token to vectors mapping is learned during training.)

Since a token itself carries no information about whether it has "authority" or not, I'm proposing to inject this information in a reserved number in that embedding vector. This needs to be done both during post-training and inference. Think of it as adding color or flavor to a token, so that it is always very clear to the LLM what comes from the system prompt, what comes from the user, and what is random data.

This is really insightful, thanks. I hadn't understood that there was room in the vector space that you could reserve for such purposes.

The response from tempaccsoz5 seems apt then, since this injection is performed/learned during post-training; in order to be watertight, it needs to overfit.

You'd need to run one model per authority ring with some kind of harness. That rapidly becomes incredibly expensive from a hardware standpoint (particularly since realistically these guys would make the harness itself an agent on a model).

I assume "harness" here just means the glue that feeds one model's output into that of another?

Definitely sounds expensive. Would it even be effective though? The more-privileged rings have to guard against [output from unprivileged rings] rather than [input to unprivileged rings]. Since the former is a function of the latter (in deeply unpredictable ways), it's hard for me to see how this fundamentally plugs the whole.

I'm very open to correction though, because this is not my area.

My instinct was that you would have an outer non-agentic ring that would simply identify passages in the token stream that would initiate tool use, and pass that back to the harness logic and/or user. Basically a dry run. But you might have to run it an arbitrary number of times as tools might be used to modify/append the context.

You just add an authority vector to each token vector. You probably have to train the model some more so it understands the authority vector.

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