Baseten Open-Sources Decision Models mammoth-1 and elephant-1
On October 22, Baseten together with the BaseLabs team released and open-sourced two "decision models": the 27B mammoth-1 and the 9B elephant-1. Officially, mammoth-1 tops the Jev Decision Index, making it the world's No. 1 decision model; elephant-1 ties for the top of the Artificial Analysis Decision Index, is the strongest under 15B, and beats Jev. All model weights are fully open-sourced, accompanied by a technical report detailing training and data methods, and both models are free on Baseten Model APIs for one week.
Confirmed
- Officially released on October 22 by Baseten and the BaseLabs team, in two sizes: 27B (mammoth-1) and 9B (elephant-1)
- All model weights open-sourced, with a technical report on training and data methods
- Both models free on Baseten Model APIs for one week
- Claimed results: mammoth-1 tops the Jev Decision Index; elephant-1 ties for the top of the Artificial Analysis Decision Index and is best under 15B
Unconfirmed
- "World's best decision model" and "strongest under 15B" are the vendor's own claims; @philipkiely also flagged them as self-reported when resharing; no independent benchmark verification appears in the materials
Why it matters
- Decision models are a new category aimed at agentic decision-making tasks; releasing with fully open weights plus a one-week free API trial lowers the barrier for community reproduction and evaluation, making third-party leaderboard validation worth watching
2026-10-22 ~ 2026-10-22 · 5 related posts
Primary sources
- [source] Baseten releases open-source decision models elephant-1 and mammoth-1, free for a week — baseten · 2026-10-22
- BaseLabs open-sources mammoth-1 and elephant-1, top-ranked decision models — saranormous · 2026-10-22
- Base Labs open-sources mammoth-1, claims world's best decision model — philipkiely · 2026-10-22
2 near-duplicate retellings: baseten · chrmanning