Type: AI model
Fable 5 is the shorthand for Anthropic’s Claude Fable 5, the publicly available, safety-gated flagship of the fifth Claude generation released June 2026. It tops most benchmarks among generally available models, including roughly 80% on SWE-Bench Pro. GROUNDING tracks Fable 5’s benchmarks, guardrails, and relationship to the partner-only Mythos 5.
Recent Updates
- 2026-08-13: DeepSeek V4 Pro official release claims state-of-the-art performance on coding and agent benchmarks (量子位) · qbitai.com — DeepSeek · Anthropic · OpenAI · DeepSeek V4 Pro · Opus 4.8 · DeepSeek-V4-Flash · GLM-5.2 · Kimi K3
- 2026-08-13: Grok 4.6 Reclaims Top Performance, Undercuts Claude and GPT Pricing; Integration with Cursor Marks New Consolidation Strategy (量子位) · qbitai.com — Agents Code Agents SpaceX · xAI · Cursor · Anysphere · OpenAI · Anthropic · Tencent · ByteDance · Alibaba · OpenRouter · Vercel · Cloudflare Elon Musk Michael Truell Aman Sanger Sualeh Asif Arvid Lunnemark · Grok 4.6 · Grok 4.5 · GPT-5.6 Sol · Claude Opus 5 Grok 4.7
- 2026-08-13: Cerebras Powers GPT-5.6 Sol Ultrafast: 750-token/second Inference in OpenAI API (Hacker News) · cerebras.ai — OpenAI · Cerebras · Artificial Analysis · GPT-5.6 Sol · Opus 4.8
- 2026-08-14: GLM-5.3 Released: Open-Source Coding Model Approaches Fable 5 Level, Becomes Strongest Open-Source Security Model (量子位) · qbitai.com — Code Agents Open Source LLMs LLM Evals Zhipu · Anthropic · OpenAI · Tsinghua University Nankai University Karpathy · GLM-5.3 · GLM-5.2 · Opus 4.8 · GPT-5.6 Sol · Mythos 5
- 2026-08-14: Maximizing the value of your Claude Code sessions (Hacker News) · claude.com — Context Engineering Anthropic · Claude
- 2026-08-17: Anthropic Publishes Claude System Prompts: Evolution from Haiku 3 to Opus 5 (Все статьи подряд / Искусственный интеллект / Хабр) · habr.com — Anthropic · Claude Haiku 3 Opus 3 Sonnet 3.5 · Opus 5
- 2026-08-19: Claude Opus 4.8 and 5.0 language calibration issues drive users to switch models (Hacker News) · github.com — Anthropic · Claude Opus 4.8 · Claude Opus 4.5 · Claude Opus 4.6 Claude Opus 5.0 · Claude Sonnet
- 2026-08-20: Using Claude to Reverse-Engineer and Develop a Driver for Legacy Drobo Storage Hardware (Hacker News) · fetzu.ch — Drobo Apple · Anthropic · Claude · Opus 4.8 · Opus 5
- 2026-08-22: Frontier Model Autonomous Agent Benchmark: NanoGPT Optimizer Speedrun Leaderboard (breakingnewsofficial) · primeintellect.ai — Agents Code Agents LLM Evals Anthropic · OpenAI · Moonshot AI · xAI · Alibaba · Zhipu · DeepSeek · Muse · Opus 5 · Kimi K3 · Opus 4.8 · GPT-5.6 Sol GPT-5.6 Sol Pro · Sonnet 5 · GPT-5.6 Luna · Grok 4.5 · Qwen 3.8 Max · GLM-5.2 · DeepSeek V4 Pro · GPT-5.6 Terra · Grok 4.6 · Muse Spark 1.2 · Muse Spark 1.1 · GPT 5.5 · Kimi K2.7
- 2026-08-23: GLM-5.3 Outperforms Claude and OpenAI Models at One-Fifth the Cost on Real-World Evaluation (breakingnewsofficial) · reinvently.co.uk — LLM Evals Anthropic · OpenAI · GLM-5.3 · GPT 5.5 · Opus 5 · Sonnet 5 · Kimi K3 · GPT-5.6 Luna
- 2026-08-24: llm-anthropic 0.27: Compatibility with anthropic v1.0.0 Python library (breakingnewsofficial) · simonwillison.net — Anthropic · OpenAI Simon Willison
- 2026-09-01: E-Commerce Bench: Evaluating LLM Agents on Long-Horizon Autonomous Business Operations (breakingnewsofficial) · arxiv.org — Agents LLM Evals OpenAI · Anthropic · Alibaba · Zhipu · DAIR.AI · GPT-5.6 Sol Qwen3.8-Max-Preview · GLM-5.2
- 2026-09-01: Fable rewrote 65kLoC of Go to Rust for $400 using data-driven transformation (breakingnewsofficial) · iurii.net — Anthropic Matt Pocock
- 2026-09-02: Fable 5.1 and Mythos 5.1 Released with 45% Cost Reduction and Anti-Distillation Security (breakingnewsofficial) · qbitai.com — Agents Anthropic · OpenAI · NASA Adaptyv Bio ESA Flix Rieseberg Ilya · Fable 5.1 Mythos 5.1 · Mythos 5 · GPT-5.6 Sol · Opus
- 2026-09-08: TradingAgents: Open-source multi-agent framework for AI-powered financial analysis (breakingnewsofficial) · github.com — Agents Agent Memory Open Source LLMs OpenAI · Anthropic · Google · Groq · Mistral · AWS · Microsoft · NVIDIA · Kimi · MiniMax · DeepSeek · Zhipu · Alibaba Alpha Vantage FRED · Polymarket StockTwits · Reddit · GPT-5.6 · GPT 5.5 · GPT-5.4 · Claude Sonnet 5 · Claude 4.6 · Gemini 3.1 Grok 4.x · Qwen · GLM
- 2026-09-10: Researchers should use open models to avoid vendor lock-in and restrictions (breakingnewsofficial) · x.com — OpenAI · Anthropic · SpaceX · xAI Buckmaster Alpöge · Claude
- 2026-09-10: Cognition Releases SWE-2 Coding Model at 64% Lower Cost Than Fable 5.1 (breakingnewsofficial) · cognition.com — Code Agents LLM Evals Cognition SWE-2 · SWE-1.7 SWE-1.72 SWE-1.6 Kimi K33 · Fable 5.1 · GPT-5.6 Sol · GPT-6 Astra · Grok 4.6
- 2026-09-11: Benchmarking RTK terminal compression: claimed 60% token savings don’t materialize in practice (breakingnewsofficial) · quesma.com — Code Agents LLM Evals Agents Anthropic · JetBrains · OpenRouter · DeepSeek V4
FAQ
What is Fable 5?
Fable 5 is the shorthand for Anthropic’s Claude Fable 5, the publicly available, safety-gated flagship of the fifth Claude generation released June 2026. It tops most benchmarks among generally available models, including roughly 80% on SWE-Bench Pro. GROUNDING tracks Fable 5’s benchmarks, guardrails, and relationship to the partner-only Mythos 5.
What does this page track?
Dated radar mentions, source links, related concepts, and builder-relevant context for Fable 5, collected automatically by GROUNDING.
When was Fable 5 last mentioned?
Fable 5 was most recently mentioned in a radar update dated 2026-09-11.
Category: Text / Language Models