Cursor's agent-swarm system rebuilt SQLite for $1,339 using Composer 2.5, versus $20,000 with larger models like Fable-5. The new architecture cut code from 64,000 lines to 9,900 by separating a frontier model that plans from worker agents that execute.
What I'm sharing on my screen here is Agent Swarms and the New Model Economics from Cursor. They rebuilt SQLite 6 different ways. This was research led by Wilson Lin on July 20th, 2026. So just a couple months ago, but I find that this article still says a lot, even in today's world. And we've been using this meta internally for my own company, Clarity. They ran an agent swarm to implement SQLite from scratch. And it was graded by this SQL Logic Test Suite. This is the Cursor blog article about it. And one of the cool things was this cost to rebuild SQLite by model mix. So you could see Opus 4.8 running tests again on Opus 5.5 as of this podcast recording would be interesting, but Opus 4.8 as the sort of brain of the operation and then Composer 2.5 ended up building SQLite at $1,339. And when you look at the very right on the spectrum in terms of cost, And efficacy, we have Fable-5 just YOLOing it at about $20,000. Right before that, GPT-5.5 at $10,000. So the architecture here was really frontier model plans, worker agents execute. And the frontier model decomposes the goals in these autonomous goal loops. And on the Fable-5 config, the old swarm wrote about 64,000 lines. And when they introduced this agent swarming meta, The new swarm wrote 9,900 lines for the same task, which is really interesting because I know Hamel and I have talked about how there's a lot of verbosity and slop that comes with AI coding agents. And that's like a tension point where in a clean architecture, it's not like you want more code all the time. You do want to slim down your code, make it more elegant and refactor. So Hamel, thoughts on this agent swarm meta from Cursor? Proving that you can get more than 10x cost optimization for value for this particular benchmark of let's rebuild SQLite.
Yeah. I mean, one thing I hope that happens soon is we move away from human orchestration of like, hey, like I'm going to use a strong model to do the planning and then a cheaper model to do the work or whatever. Because it's just a really bad user experience to like, Do the routing in your head. And so that's one thing to kind of think about. Like if you're just, yeah, I mean, you're, if you're lazy or you don't have time, you know, you are like the person on the right using Table 5 all the way. Cause you're like, I don't know. I like, I'm not going to sit here and orchestrate this. So there is some human complexity element here. Composer 2.5 is really good. It's fine-tuned. I believe it was like fine-tuned KIMI model from Cursor. That's right.
Yeah.
And it's really fast. It's really good if you're using Cursor. Um, again, this makes sense, except I would love to see some kind of model routing baked in. Like, could you do this with Composer 2.5 all the way? I would like to see that as a baseline. Like, what happens there? I'm really curious.
