# Qwen3.5-4B-Router-1M decision model by Maziyar Panahi > Qwen3.5-4B-Router-1M is an open adapter for agent tool and action routing. See the actual training size, source-label results and trace-judging limits. Updated 2026-11-07 (Australia/Adelaide) ## Quick answers ### What is Qwen3.5-4B-Router-1M by Maziyar Panahi? [Qwen3.5-4B-Router-1M](): A Qwen3.5-4B LoRA and Unsloth decision head for next-action and tool routing. [Qwen3.5-4B-Router-1M facts]() [Source]() ### Who makes Qwen3.5-4B-Router-1M? [Qwen3.5-4B-Router-1M](): Maziyar Panahi [Qwen3.5-4B-Router-1M facts]() [Source]() By Maziyar Panahi · Weights upload: 2026-11-06 · OPEN A Qwen3.5-4B LoRA and Unsloth decision head for next-action and tool routing. Training used 17,600 source-labelled rows; the name refers to the larger merged data pool. [Jev]() answers were excluded from training. It is unsuitable as a general trace judge. ## Facts - Base and size: Qwen3.5-4B; adapter and separate decision head - Inputs: Software-agent and customer-service traces - Context: 4,096 tokens; reported test states up to 13,000 characters - Licence: Apache-2.0 - Access: Public adapter; Unsloth FastDecisionModel and base weights required ## Claims and sources - **VENDOR-REPORTED**: The maker reports 86.5% agreement with source labels on 480 held-out rows, against stored [Jev]() 1.13 answers at 80.6%. These labels describe the source trace’s next action or parsed tool call, not human correctness. Trace-disposition results are weak. [source]() ## Links - [Source: Model card and weights]() ## Related projects No related projects are listed in the registry.