{
 "slug": "Claude_Opus_4.5",
 "title": "Claude Opus 4.5",
 "type": "model",
 "short_desc": "Anthropic's November 2025 flagship: developer-reported coding leadership with a major price cut, closing the Claude 4.x series.",
 "categories": [
  "Anthropic models",
  "Models",
  "Reasoning models",
  "2025 model releases"
 ],
 "infobox": {
  "Developer": "Anthropic",
  "Family": "Claude",
  "Predecessor": "Claude 4 series (via Opus 4.1)",
  "Successor": "Claude Opus 4.6-4.8 (2026)",
  "Announced": "November 2025",
  "Architecture": "Transformer-based hybrid reasoning model; details undisclosed",
  "Parameters": "Undisclosed",
  "Context window": "200,000 tokens",
  "Post-training": "Constitutional AI, RLHF-family, reasoning RL",
  "License / access": "Proprietary; API, claude.ai, cloud partners",
  "Paper/report": "Claude Opus 4.5 announcement and system card (November 2025)"
 },
 "infobox_links": {
  "Developer": [
   "Anthropic"
  ],
  "Family": [
   "Claude_(model_family)"
  ],
  "Predecessor": [
   "Claude_4"
  ],
  "Successor": [
   "Claude_Opus_4.6"
  ],
  "Architecture": [
   "Transformer_(architecture)"
  ],
  "Post-training": [
   "Constitutional_AI",
   "Reinforcement_learning_from_human_feedback"
  ]
 },
 "aliases": [],
 "family": "Claude (model family)",
 "org": "Anthropic",
 "registry_status": "stub",
 "words": 294,
 "references": 3,
 "outbound": [
  "Anthropic",
  "Claude_(model_family)",
  "Claude_4",
  "Claude_Opus_4.6",
  "Constitutional_AI",
  "DeepSeek_(model_family)",
  "GPT-5.1",
  "Gemini_3",
  "Google_DeepMind",
  "Kimi_(model_family)",
  "MMLU",
  "OpenAI",
  "Reinforcement_learning_from_human_feedback",
  "Test-time_compute",
  "Transformer_(architecture)"
 ],
 "inbound": [
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  "Grok_4.1",
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  "Qwen3-Coder-Next"
 ],
 "url": "wiki/Claude_Opus_4.5.html",
 "built": "2026-07-24"
}