[Not finished][Do not review]

[AutoLTX]

End-user friendly description of the problem this fixes or functionality that this introduces

• Include this change in the Release Notes. If checked, you must provide an end-user friendly description for your change below

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Give a summary of what the PR does, explaining any non-trivial design decisions

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[enyst]

What if we added it, instead of observation, to the action? Somewhere

• after we got it from the agent at line 689

action = self.agent.step(self.state)

• and just before it's added to the event stream, like before this line 751

self.event_stream.add_event(action, action._source)  # type: ignore [attr-defined]

Then it would be saved in the stream, so the server would be able to read it in its dict it sends to frontend. 🤔

I think we have some difficult problem atm with sending extra bits of information to the frontend, I'm sorry about that. This idea might be one way to do it, and it should work for our purpose.

[enyst]

@AutoLTX Thank you for the work on this!

Please don't worry about the fact that it's unfinished, it's fine, that's why it's a draft. Everyone does temporary stuff in a draft.

This PR ends up much more complex than we first thought, I apologize about that! We seem to have two difficulties here:

• (backend) sending extra information to the frontend is non-obvious. There is no channel other than events themselves, and an error callback channel, I think.
• (frontend) frontend just had or has a redesign, and frontend folks will need to check changes so that we don't introduce inconsistencies or issues with the rest.

What do you say if we split this PR in two, maybe three:

• backend stuff, see that the info is actually sent; unit tests
• frontend - display accumulated cost
• frontend - page with details on cost

That may make it easier to keep in sync with the high activity here, and easier to review and approve.