Anthropic: Claude Fable 5
Chatanthropic/claude-fable-5Claude Fable 5 is Anthropic's Mythos-class model, released on 2026-06-09 and built for long-horizon agentic autonomy — work that unfolds over extended sessions rather than a single prompt. It supports reasoning, vision, tool use, PDF input, and prompt caching, making it suitable for agents that must stay coherent across many steps. Context window: 1M tokens, output: 128K. Its 1M-token context and PDF input make it practical to feed whole document sets or repositories into a single session, while prompt caching keeps repeated context affordable. Accessible via the native Anthropic protocol through Ofox.
Providers
Code Examples
import anthropicclient = anthropic.Anthropic(base_url="https://api.ofox.io/anthropic",api_key="YOUR_OFOX_API_KEY",)message = client.messages.create(model="anthropic/claude-fable-5",max_tokens=1024,messages=[{"role": "user", "content": "Hello!"}],)print(message.content[0].text)
Uptime & Status
Benchmarks
Anthropic: Claude Fable 5 scores 1507 in the Overall category of the LMArena text leaderboard (style control), ranking #1 of 374 models based on 7,856 human preference votes (updated 2026-07-12).
| Category | Arena Score | 95% CI | Rank | Votes |
|---|---|---|---|---|
| Overall | 1507 | 1500–1515 | #1 of 374 | 7,856 |
| Hard Prompts | 1534 | 1526–1543 | #1 of 374 | 5,239 |
| Coding | 1548 | 1535–1561 | #4 of 369 | 2,184 |
| Math | 1551 | 1522–1580 | #1 of 362 | 398 |
| Creative Writing | 1509 | 1493–1525 | #1 of 372 | 1,446 |
| Instruction Following | 1514 | 1502–1526 | #1 of 374 | 2,752 |
| Chinese | 1549 | 1519–1578 | #2 of 344 | 439 |
Source: LMArena · CC BY 4.0 · Updated 2026-07-12 · Methodology ↗ · Ranks compare models within each category of the LMArena text leaderboard (style control). Scores come from third-party human preference evaluations, not from OFOX.