Devstral 2 is open source, 123B params, hits 72.2% SWE-bench, and costs a seventh of Sonnet

When the meter's running hot, the obvious move is a cheaper model that's actually good. Mistral shipped one. Devstral 2 (123B, modified MIT) scores 72.2% on SWE-bench Verified. Devstral Small 2 (24B, Apache 2.0) hits 68.0%. Both carry 256K context. Mistral claims 7x cost efficiency over Claude Sonnet at $0.40/$2.00 per million tokens, currently free via the API. Devstral Small 2 at $0.10/$0.30 runs on consumer hardware, which makes it the most capable coding model you can run locally right now (Mistral).

They didn't stop at the weights. Vibe CLI shipped alongside it, Apache 2.0, an open-source terminal coding agent with project-aware context scanning and multi-file orchestration, available as a Zed extension over Agent Communication Protocol (GitHub). First open-source terminal agent from a major model lab. Mistral also rebranded Le Chat to Vibe, a unified work-plus-code platform with GitHub sandbox sessions that open real PRs (Mistral).

This is the direct counter-narrative to story one. Tokenmaxxing breaks budgets because frontier inference is expensive and unbounded. A 7x-cheaper open model that you can also self-host changes the math on persistent agents specifically, the workloads that run all the time and rack up cost while idle-thinking.

I'm skeptical of the headline benchmark, the way I'm skeptical of all of them. 72.2% SWE-bench Verified is real but SWE-bench is not your codebase. What I actually care about is the Small 2 number. A 24B model at 68% that runs on a workstation means I can put a coding agent on a private repo with zero per-token cost and zero data leaving the building. That's the unlock. Frontier models for the hard 20%, local Devstral Small for the boilerplate 80%.

What to do: pull Devstral Small 2 this week and point it at a real repo, not a benchmark. Measure how far it gets on routine work before you escalate. If it handles your boilerplate, you've just removed those tokens from your bill entirely. Pair it with a router (see Manifest, below) so the expensive model only fires when complexity demands it.