gpt-oss-120b-speculator.eagle3

Model Overview

• Verifier: openai/gpt-oss-120b
• Speculative Decoding Algorithm: EAGLE-3
• Model Architecture: Eagle3Speculator
• Release Date: 03/10/2026
• Version: 2.0
• Model Developers: RedHat

This is a speculator model designed for use with openai/gpt-oss-120b, based on the EAGLE-3 speculative decoding algorithm. It was trained using the speculators library on a combination of the Magpie-Align/Magpie-Llama-3.1-Pro-300K-Filtered dataset and the train_sft split of the HuggingFaceH4/ultrachat_200k dataset. Training data used Magpie + UltraChat with responses from the gpt-oss-120b model (reasoning). This model should be used with the openai/gpt-oss-120b chat template, specifically through the /chat/completions endpoint.

vLLM version

This draft model uses norm_before_fc (pre-FC RMSNorm for gpt-oss Eagle3). You need vLLM that includes PR #38111 (merged 2026-03-12).

• Use vLLM >= 0.19.0 (includes the necessary fix from PR #38111.

Use with vLLM

vllm serve openai/gpt-oss-120b \
 --tensor-parallel-size 4 \
 --speculative-config '{
 "model": "RedHatAI/gpt-oss-120b-speculator.eagle3",
 "num_speculative_tokens": 5,
 "method": "eagle3"
 }' \
 --no-enable-prefix-caching \
 --max-num-seqs 64 \
 --enforce-eager

Evaluations

Model / run: gpt-oss-120b-from-self-ckpt5
vLLM: 0.17.1rc1.dev531+g89f572dbc.d20260324
Training data: Magpie + UltraChat; responses from the gpt-oss-120b model (reasoning).

Use cases

Acceptance lengths (draft length, temperature=default)