# Rein r1 family decision model by jmc0 > Rein r1 uses open decision models to steer chat replies and tool calls. Compare its two sizes, rule-based interface and maker-reported test limits. Updated 2026-11-07 (Australia/Adelaide) ## Quick answers ### What is Rein r1 family by jmc0? [Rein r1 family](): Open 0.8B and 4B decision models that steer a separate chat model using rules supplied per request. [Rein r1 family facts]() [Source]() ### Who makes Rein r1 family? [Rein r1 family](): jmc0 [Rein r1 family facts]() [Source]() ### Are Rein r1 family's weights open? [Rein r1 family](): Public merged backbone and decision-head weights Licence: Apache-2.0, per both cards [Rein r1 family facts]() [Source]() By jmc0 · Weights upload: 2026-11-06 · OPEN Open 0.8B and 4B decision models that steer a separate chat model using rules supplied per request. Turn and partial-draft judgments can request tools, enforce an opening phrase or stop a reply. Rein returns decisions; the chat model writes the text. ## Facts - Variants: Rein-r1-0.8B and Rein-r1-4B - Inputs: Rule sheets and text conversations; English and Portuguese best measured - Runtime: Custom Transformers decision and session-control code - Licence: Apache-2.0, per both cards - Access: Public merged backbone and decision-head weights ## Claims and sources - **VENDOR-REPORTED**: The maker reports 96.8% decision accuracy and 0.003 ECE for 4B on 28,430 questions about held-out rules. Labels are synthetic and audited by another model. End-to-end chat tests still contain rule violations; they are small sampled sessions judged by Qwen. [source]() ## Links - [Source: Model card and weights]() - [Source: 0.8B card and weights]() ## Related projects No related projects are listed in the registry.