schneewolflabs/B0-27B

VISIONPricing:Input $1.6 / Cached $0.15 / Output $12Concurrent Unit Cost:2Model Size:27BQuant:FP8Context Size:32kTool Calling:SupportedPublished:Sep 4, 2026License:apache-2.0Architecture:Transformer0.0K Open Weights Featherless Exclusive Cold

schneewolflabs/B0-27B is a 27 billion parameter base model from Schneewolf Labs, built upon Hemlock-Qwen3.8-27B and fine-tuned with a directness substrate and an identity capstone using ORPO. This model is designed as a local operator with a distinct personality, excelling at end-to-end engineering work and task completion, demonstrating faster performance on sandboxed engineering tasks compared to its base. It maintains strong safety characteristics and includes vision capabilities, supporting draft-mtp for multimodal applications.

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Schneewolf Labs B0-27B: An Engineering-Focused Base Model

B0-27B is Schneewolf Labs' internal 27 billion parameter base model, forming the foundation of their "Familiar" line. It is developed from Hemlock-Qwen3.8-27B through a two-rung fine-tuning process:

  • Directness Substrate: A merged base mix incorporating elements like weasel, grok-pi, and seX-ai to enhance directness.
  • Identity Capstone: An ORPO-trained layer (i-DPO, Luna-DPO, MahouMix rebuild) applied to instill a distinct personality and optimize for specific behaviors, including tool ballast and destructo.

Key Capabilities & Performance

This model is engineered to function as a local operator with a personality, capable of performing real engineering work end-to-end. While it shows a slight dip in single-tool-call reflexes on the egirl 47-case operator bench (42/47 vs 47/47 for its base), it significantly improves end-to-end task completion.

  • Faster Task Completion: On the kirabench, which involves six sandboxed engineering tasks, B0-27B achieves 6/6 task completion, notably fixing a failing-test task approximately 9 times faster than its Hemlock base.
  • Safety & Stance: It demonstrates strong censorship (28/29) and safety asymmetry (2/2), refusing actual harm, while maintaining a lower stance rate (8.3%) compared to its base.
  • Multimodal Support: The model retains the vision tower and mtp.* tensors from its base, supporting --spec-type draft-mtp for multimodal applications.

Training Details

Preference training was conducted using Merlina (ORPO r32/α64 lr 8e-6). The substrate adapter was hand-merged, and the capstone was trained on the resulting merge, ensuring gains were preserved while costs were overwritten. MahouMix was rebuilt on-policy, with rejected responses regenerated from the substrate-merged model itself.