Model · Anthropic · Text
Claude Fable 5
Anthropic's most capable widely released model — the first public Mythos-class model, a tier above Opus 4.8 for the most demanding reasoning and long-horizon agentic work.
- Modality
- Text
- License
- Proprietary (Proprietary)
- Context window
- 1,000,000 tokens
- Released
- June 9, 2026
- Last verified
- June 10, 2026
- Runs locally
- No
- Also handles
- vision
Strengths
- State-of-the-art on most tested benchmarks — software engineering, knowledge work, vision, and scientific research
- 1M-token context with up to 128k output
- Adaptive thinking always on
Weaknesses
- Most expensive Claude tier ($10/$50 per MTok) — double Opus 4.8
- Safeguard routing: cybersecurity and biology queries are answered by Opus 4.8 instead
- Closed weights — cannot be self-hosted
Try it
| Where | Type | Notes |
|---|---|---|
| Anthropic API | hosted-api | API key required |
| AWS Bedrock | hosted-api | Enterprise / regional |
| Google Vertex AI | hosted-api | GCP integration |
| Claude.ai | product | Paid plans (Pro and above) |
Version history
- Claude Fable 5 Jun 2026 Current
- Claude Mythos 5 Jun 2026
Official sources
- Model docs docs
- Announcement announcement
Change log
- — Initial entry. Released 2026-06-09 as Anthropic's most capable widely released model — the first publicly available Mythos-class model, a new tier above Opus 4.8.
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