Axion 1.0-35B — Reproduction

Paper · Project · Code · Training Data

This repository provides a reproduction checkpoint of Axion 1.0-35B, following the recipe described in Axion 1.0: Open Agent Foundation Models, Simplified. The model is designed for scientific reasoning, information seeking, and tool-augmented problem solving.

Model Overview

Property Details
Model Axion 1.0-35B
Release Reproduction checkpoint
Architecture Mixture of Experts (MoE)
Parameters Approximately 35B total, 3B active
Weight precision BF16

The training recipe combines approximately 18K SFT examples with three stages:

  1. Learn to reason: supervised fine-tuning on challenging, self-contained scientific problems constructed with model-aware feedback.
  2. Learn to investigate: supervised fine-tuning on verifiable tasks requiring external information and tool use.
  3. Learn through interaction: reinforcement learning over agent trajectories to refine reasoning and interaction with tools.

Performance

The table compares paper-reported results with the results of the reproduction checkpoint released in this repository. All scores are percentages; higher is better.

Model HLE BMB SEAL‑0 HiPhO FS Olympiad FS Research
Agents-A1 47.6 — 56.4 46.4 79.0 40.0
Kimi-K2.6 54.0 — 50.5 41.1 73.0 17.9
DeepSeek-V4-Pro (Preview) 48.2 — 55.0 38.7 76.0 13.3
Apodex 1.1 (ReAct) 53.2 23.5 — — — 55.0
Apodex 1.1 (Agent Team) 56.1 35.3 — — — 63.3
GPT-5.5 52.2 — 42.3 43.3 78.0 26.7
GPT-5.6 Sol — 47.1 53.2 42.9 79.0 63.3
GPT-6 Astra 57.2 — — — — —
Muse-Spark-1.0 58.0 — — — — 38.0
Gemini 3.1 Pro 51.4 35.3 53.2 38.5 85.0 26.7
Claude Opus 5 63.6 49.4 — — — —
Claude Fable 5 63.8 46.1 — — — —
Axion 1.0-35B (Paper) 52.2 35.3 62.2 45.7 86.0 56.7
Axion 1.0-35B (Reproduction) 52.8 35.3 60.4 45.9 85.0 55.0

HLE denotes the full Humanity's Last Exam benchmark; BMB uses the human-difficult BioMysteryBench subset. FS denotes FrontierScience. A dash indicates an unreported result. Bold highlights the reproduction checkpoint released in this repository.

Usage

Following the repository's inference guide, serve the released checkpoint with vLLM:

vllm serve Axion1-0/Axion-1.0-35B \
  --served-model-name axion-35b \
  --host 127.0.0.1 --port 8000 \
  --tensor-parallel-size 8 --dtype bfloat16 \
  --max-model-len 131072 \
  --reasoning-parser qwen3 \
  --enable-auto-tool-choice --tool-call-parser qwen3_coder

This example uses eight GPUs. Adjust tensor parallelism and context capacity to fit your GPU memory.

Call the OpenAI-compatible endpoint:

curl --fail-with-body http://127.0.0.1:8000/v1/chat/completions \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "axion-35b",
    "messages": [
      {"role": "user", "content": "What is 2 + 3?"}
    ],
    "max_tokens": 1024
  }'

Tool-using agent evaluation additionally requires a harness that executes tool calls. See the inference guide for details.

License

This model is released under the Apache License 2.0. See LICENSE for details.

Citation

@misc{jia2026axion,
  title         = {Axion 1.0: Open Agent Foundation Models, Simplified},
  author        = {Yuqi Jia and Yunjie Tian and Jiayu Zheng and Yijun Liang and Jingchen Sun and Mengyu Zhao and Di Fu},
  year          = {2026},
  eprint        = {2611.03233},
  archivePrefix = {arXiv},
  primaryClass  = {cs.AI},
  url           = {https://arxiv.org/abs/2611.03233}
}
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