Save 30% token costs when using Claude Code, Codex, OpenCode for free - with open source, local semantic search. Works for small and large codebases and monorepos! Enterprise-ready and fully compliant via Ollama and SQLite-vec.
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Why should I trust that what you're peddling isn't snakeoil?> Of course, it's always dependent on statistical noise + host system load, and running sufficiently large benchmarks is simply too expensive, so take em with a grain of salt.
And the savings listed are coming from a benchmark harness that implements different OSS bugs one time with and one without lumen - in those cases the % saved are reproducible (caveat: it was on older models, Opus 4.6 I believe).
Also I explain WHY it saves tokens - because the model doesn’t have to brute force different terms until it finds the match it needs, but uses semantic „distance“ so the embedding does it for the model.
I’m using less tokens with Lumen but I also use a bunch of other tokens hacks/skills; it’s hard to measure the impact exactly but it feels significant
But anecdotally I do think it saves me quite a lot of time on reading LLM outputs. And that, if nothing else, is good for my sanity.
The caveman gimmick makes sense to me as a clever hack. Caveman talk is a longstanding meme that's presumably well-represented in the models' training data. So just asking it to do that is just an ultra-concise way to tell the LLM to be ultra-concise. Which, in turn, is theoretically good for accuracy because putting too many instructions in the prompt is bad for task performance.
https://github.com/dirac-run/dirac
I spent way too long trying to reproduce the results in Pi and failing before I decided that I shouldn't trust author benchmarks for any of these tools. Then I found that I couldn't even close to reproduce their benchmark results using the exact model and their harness.
If any person other than the author has time to verify these Lumen benchmark results I'd be curious to hear it. I don't have the time to do it myself at the moment.
When caveman was released, token efficiency was a lot more relevant. But in the time I've actually come to like its matter-of-fact and short way of responding. There are other similar ones, but caveman is familiar.
https://blog.jetbrains.com/ai/2026/05/what-happens-when-you-...
What makes it incompatible with Pi, Zed or any other harness?
the kinda guy who honestly thinks caveman.md reduces costs, actually adds it to his system prompt and is painstakingly reading the terse output