So the reason that Claude code is capable of outputting valid json is because if the prompt text suggests it should be JSON then it enters a special loop in the main query engine that just validates it against JSON schema (it looks like the schema just validates that something in fact and object and its keys are strings) and then feeds the data with the error message back into itself until it is valid JSON or a retry limit is reached.

This code is so eye wateringly spaghetti so I am still trying to see if this is true, but this seems to be how it not only returns json to the user, but how it handles all LLM-to-JSON, including internal output from its tools. There appears to be an unconditional hook where if the JSON output tool is present in the session config at all, then all tool calls must be followed by the "force into JSON" loop.

If that's true, that's just mind blowingly expensive

edit: please note that unless I say otherwise all evaluations here are just from my skimming through the code on my phone and have not been validated in any way that should cause you to be upset with me for impugning the good name of anthropic

edit2: this is both much worse and not as bad as i thought on first read - https://neuromatch.social/@jonny/116326861737478342

reminder that anthropic ran (and is still running) an ENTIRE AD CAMPAIGN around "Claude code is written with claude code" and after the source was leaked that has got to be the funniest self-own in the history of advertising because OH BOY IT SHOWS.

it's hard to get across in microblogging format just how big of a dumpster fire this thing is, because what it "looks like" is "everything is done a dozen times in a dozen different ways, and everything is just sort of jammed in anywhere. to the degree there is any kind of coherent structure like 'tools' and 'agents' and whatnot, it's entirely undercut by how the entire rest of the code might have written in some special condition that completely changes how any such thing might work." I have read a lot of unrefined, straight from the LLM code, and Claude code is a masterclass in exactly what you get when you do that - an incomprehensible mess.

from @sushee over here, (can't attach images in quotes) and apparently discussed on HN so i'm late, but...

They REALLY ARE using REGEX to detect if a prompt is negative emotion. dogs you are LITERALLY RIDING ON A LANGUAGE MODEL what are you even DOING

OK i can't focus on work and keep looking at this repo.

So after every "subagent" runs, claude code creates another "agent" to check on whether the first "agent" did the thing it was supposed to. I don't know about you but i smell a bit of a problem, if you can't trust whether one "agent" with a very big fancy model did something, how in the fuck are you supposed to trust another "agent" running on the smallest crappiest model?

That's not the funny part, that's obvious and fundamental to the entire show here. HOWEVER RECALL the above JSON Schema Verification thing that is unconditionally added onto the end of every round of LLM calls. the mechanism for adding that hook is... JUST FUCKING ASKING THE MODEL TO CALL THAT TOOL. second pic is registering a hook s.t. "after some stop state happens, if there isn't a message indicating that we have successfully called the JSON validation thing, prompt the model saying "you must call the json validation thing"

this shit sucks so bad they can't even CALL THEIR OWN CODE FROM INSIDE THEIR OWN CODE.

Look at the comment on pic 3 - "e.g. agent finished without calling structured output tool" - that's common enough that they have a whole goddamn error category for it, and the way it's handled is by just pretending the job was cancelled and nothing happened.

So ars (first pic) ran a piece similar to the one that the rest of the tech journals did "claude code source leaked, whoopsie! programmers are taking a look at it, some are finding problems, but others are saying it's really awesome."

like "inspiring and humbling" is not the word dog. I don't spend time on fucking twitter anymore so i don't hang around people who might find this fucking dogshit tornado inspiring and humbling. Even more than the tornado, i am afraid of the people who look at the tornado and say "that's super fucking awesome, i can only hope to get sucked up and shredded like lettuce in a vortex of construction debris one day"

the (almost certainly generated) blog post is the standard kind of vacuuous linkedin shillposting that one has come to expect from the gambling addicts, but i think it's illustrative: the only thing they are impressed with is the number of lines. 500k lines of code for a graph processing loop in a TUI is NOT GOOD. The only comments they make on the actual code itself is "heavily architected" (what in the fuck does that mean), "modular" (no the fuck it is not), and it runs on bun rather than node (so??? they own it!!!! of course it does!!!). and then the predictable close of "oh and also i'm also writing exactly the same thing and come check out mine"

the only* people this shit impresses are people who don't know what they're looking at and just appreciate the size of it all, or have a bridge to sell.

* I got in trouble last time i said "only" - nothing in nature is ever "only this or that," i am speaking emphatically and figuratively. there are other kinds of people who are impressed with LLMs too. Please also note that my anger is directed towards the grifters profiting off of it and people who are pouring gas on the fire and enabling this catastrophe by giving it intellectual, social, and other cover. I know there are folks who just chat with the bots because they need someone to talk to, etcetera and so on. people in need who are just making use of whatever they can grab to hang on are not who I am criticizing, and never are.