{
 "schema_version": "1.7.0",
 "id": "x_NXMC-2026-0117",
 "modified": "2026-11-04T22:37:22.465Z",
 "published": "2026-11-04T22:37:22.465Z",
 "summary": "Qwen3.5-9B: tokenizer change at ef3d031 (2026-03-01)",
 "details": "Qwen3.5-9B: the chat template text changed but rendered byte-identically on the three fixed conversations (system+user, multi-turn, tool call), all of which end on a user turn; a conversation ending on an assistant turn (training data, prefill) was not rendered; tokenizer model_max_length 131072 to 262144; truncation defaults change (2026-03-01).\n\nRepository: https://huggingface.co/Qwen/Qwen3.5-9B. Revisions from ef3d031a90d340a92d71f83ec17d054e100ce713 onward carry this change; a pin at 21eca8a083a2121a92fba681f4a7c72cf20ff1a7 or earlier does not.\n\nChanged keys:\n- tokenizer chat_template_sha256: 04b007131663760b -> a4aee8afcf2e0711 (template)\n- tokenizer model_max_length: 131072 -> 262144 (tokenizer)\n\nThis record says what the change does mechanically. It is not a report that anything broke for anyone.",
 "affected": [
  {
   "ranges": [
    {
     "type": "GIT",
     "repo": "https://huggingface.co/Qwen/Qwen3.5-9B",
     "events": [
      {
       "introduced": "ef3d031a90d340a92d71f83ec17d054e100ce713"
      }
     ]
    }
   ],
   "database_specific": {
    "model": "Qwen/Qwen3.5-9B",
    "previous_revision": "21eca8a083a2121a92fba681f4a7c72cf20ff1a7"
   }
  }
 ],
 "references": [
  {
   "type": "INTRODUCED",
   "url": "https://huggingface.co/Qwen/Qwen3.5-9B/commit/ef3d031a90d340a92d71f83ec17d054e100ce713"
  },
  {
   "type": "PACKAGE",
   "url": "https://huggingface.co/Qwen/Qwen3.5-9B"
  },
  {
   "type": "WEB",
   "url": "https://www.neurarch.com/changes-feeds/models/Qwen/Qwen3.5-9B.html"
  }
 ],
 "database_specific": {
  "source": "neurarch model change tracker",
  "model": "Qwen/Qwen3.5-9B",
  "kind": "tokenizer",
  "classes": [
   "tokenizer",
   "template"
  ],
  "changed_keys": [
   {
    "file": "tokenizer",
    "key": "chat_template_sha256",
    "before": "04b007131663760b",
    "after": "a4aee8afcf2e0711",
    "class": "template"
   },
   {
    "file": "tokenizer",
    "key": "model_max_length",
    "before": 131072,
    "after": 262144,
    "class": "tokenizer"
   }
  ],
  "impact": {
   "memory": false,
   "serving": true,
   "tokenizer": true,
   "licence": null
  },
  "breaking": false,
  "breaking_rule": "https://www.neurarch.com/changes-feeds/advisories/index.json#breaking_rule",
  "consequence": {
   "params": null,
   "weightsGbBf16": null,
   "trainPeakGb": null,
   "fingerprint": null,
   "context": null,
   "eos": null,
   "bos": null,
   "derivedSame": true
  },
  "commit_date": "2026-03-01T14:58:17.000Z",
  "detected_at": "2026-11-04T22:37:22.465Z",
  "detected_by": "backfill",
  "days_since_first_commit": 2,
  "license": "CC-BY-4.0"
 }
}