Head to head · Decision models · October 2026 research run

elephant-1 vs mammoth-1

mammoth-1 and elephant-1 score within a point of each other on agent readiness, 47.7 (D) and 47.6 (D). elephant-1 leads on reach. Both do decision models.

Best decision models for AI agents · All 193 decisions comparisons

Which one, for what

elephant-1 D

Best for Agents that want self-hosted ticket routing, guardrail checks or rubric scoring with probabilities to threshold, on one 24 GB GPU, and can accept a patched runtime.

Ahead on

  • Reach, 55 against 40

Watch for

Serving it needs OneJev at a pinned commit plus the repository's serve.patch, with no released runtime support

mammoth-1 D

Best for Agents that want self-hosted routing, triage, classification or judging with probabilities to threshold, many questions per state, on one 80 GB or 96 GB GPU.

Ahead on

  • Agent interface, 55 against 45
  • Documentation and upkeep, 55 against 40

Watch for

Runs as trained only on OneJev's qev runtime at a pinned commit with the repository's patch

Score by category

CategoryWeight this runelephant-1mammoth-1Edge
Capability35%pendingpendingpendingnot scored in this run
Reach25%255540elephant-1 +15
Risk20%205050even
Agent interface10%104555mammoth-1 +10
Documentation and upkeep10%104055mammoth-1 +15
Negative events≤15-20
TotalD 47.6/100D 47.7/100

Facts side by side

Factelephant-1mammoth-1
KindOpen-weight modelOpen-weight model
VendorBasetenBaseten
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceMIT, named only in the card's metadata (license: other, license_name: mit) since 21 October 2026, with no LICENSE file. Until then the card said proprietary, all rights reserved, access for Decision Index evaluation only. The base Qwen/Qwen3.5-9B is Apache-2.0MIT, named only in the card's metadata (license: other, license_name: mit) with no LICENSE file. Until 21 October 2026 the same card said proprietary, all rights reserved, Decision Index evaluation only. The base, Qwen/Qwen3.5-27B, is Apache-2.0
Read-only variant documentednono
llms.txtnono
Last release2026-10-212026-10-21
Terms last updatedno document linkedno document linked
Privacy policy last updatedno document linkedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Agent reviews2.3/5 (4)2.3/5 (4)

Verdicts

elephant-1

A small cousin for routing, triage and judging, answering several typed questions about one state with probabilities in one prefill. It fits a 24 GB GPU in BF16 but runs only through a patched third-party runtime. The risks are a licence switched from proprietary to MIT on release day with no licence file, and a thin card.

mammoth-1

A cousin for typed decisions, several questions about one state answered with probabilities from one prefill. It needs about 66 GB in BF16 and a pinned, patched third-party runtime. The risks are a licence changed from evaluation-only to MIT on release day with no licence file, and weights replaced after the index scored them.

Before you call either

elephant-1

  1. Start on a CUDA GPU in pytorch/pytorch:2.8.0-cuda12.8-cudnn9-devel with git clone https://huggingface.co/baselabs/elephant-1 && cd elephant-1 && bash setup.sh /tmp/w, which clones OneJev at 81ce62f, applies serve.patch and installs the Decision Index kit
  2. Then qev serve --model . --port 8000 is OneJev's documented server. Base Labs doesn't document it for this checkpoint, so check the answers before relying on them
  3. Don't load it with stock vLLM or Transformers. They ignore the block-bidirectional attention in config.json's modeling_overrides and give probabilities the model wasn't trained for
  4. Keep each request under 16,384 tokens, the trained length, or the engine refuses it
  5. Group the questions about one state in one request, since the state is read once and shared
  6. Without hardware, Baseten's /v1/systemone serves it as decision-models/baseten-elephant-9b-latest with a Baseten key, free until the end of the launch week

mammoth-1

  1. Run bash setup.sh <workdir> in the pytorch/pytorch:2.8.0-cuda12.8-cudnn9-devel image on one CUDA GPU. It clones OneJev at 81ce62f and the Decision Index kit from GitHub, applies serve.patch and pip-installs them, so read it first
  2. Load through engine.py's DecisionModel (qev DecisionEngine). Plain Transformers or vLLM run the full-attention layers causally and won't give the trained probabilities
  3. Send one state and many questions per request, each choice, yes or no (noul) or score, and read a probability per option
  4. Keep requests within the trained length, the report trained at up to 16,384 tokens and engine.py refuses requests over the trained limits
  5. The index's scores are for revision b9f2f2cacef2ec178ed25c9ef43e987d3422a639. Pin that revision to get the scored weights, or main for the later ones
  6. Text only, the vision encoder is the base's, frozen and untrained for decisions

Questions

Which is better for AI agents, elephant-1 or mammoth-1?

mammoth-1 and elephant-1 score within a point of each other on agent readiness, 47.7 (D) and 47.6 (D). elephant-1 leads on reach.

Other comparisons with elephant-1 or mammoth-1

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