Mammoth-1 and Elephant-1
Baseten's open decision models (27B and 9B) that return probabilities for choice, score, and yes/no questions instead of text.
This entry is marked for review. Check the original sources before relying on its details.
Overview
Baseten released mammoth-1 (27B) and elephant-1 (9B) on October 21, 2026 as open-weight decision models that return a probability distribution over answers rather than generating text. Per Baseten's blog they were post-trained from Qwen3.5-27B and Qwen3.5-9B; both support a 16k-token context. Baseten reports mammoth-1 scoring 71.24 on the Jev Decision Index 0.4 and 65.9 on the Artificial Analysis Decision Index (elephant-1: 65.2), vendor-reported and not independently verified. They are served through Baseten Model APIs (System One endpoint) and offered free on Vercel AI Gateway through October 27.
This is a sourced directory entry. Features and capabilities are reported in the linked sources; this entry does not document independent Aymorphic testing.
Key features
- Decision outputs: choice, score, and yes/no probabilities, multiple questions per request
- mammoth-1 27B and elephant-1 9B, 16k-token context
- Vendor-reported 71.24 (mammoth-1) on Jev Decision Index 0.4; 65.9 and 65.2 on Artificial Analysis Decision Index
- Served via Baseten Model APIs System One endpoint with zero data retention by default
- Free on Vercel AI Gateway through October 27, 2026
Use cases
- Text classification and request routing
- Scoring content against a rubric in one low-latency call
Pricing
Free to try for a week on Baseten Model APIs and free on Vercel AI Gateway through October 27, 2026; paid pricing and license not stated in the sources reviewed.
Pricing reflects the source record and may change. Confirm current terms with the provider.
Dates and sources
- Released
- 21 Oct 2026
- Record updated
- 23 Oct 2026
- Record last checked
- 23 Oct 2026
- baseten.co/resources/changelog/elephant-1-and-mammoth-1-available-on-baseten/
- baseten.co/blog/the-best-decision-models-in-the-world-mammoth-1-and-elephant-1
- vercel.com/changelog/basetens-mammoth-1-and-elephant-1-now-available-on-ai-gateway-for-free
- runtimewire.com/article/base-labs-mammoth-elephant-decision-models