Model · Multimodal language model
Claude Fable 5
A pinned Mythos-class Claude release in legacy status with a 1M-token context, available through Anthropic's developer API and documented third-party cloud platforms, without downloadable model weights.
- Developer
- Anthropic
- Distribution
- Developer API · Third-party hosting
- Artifact licensing
- Proprietary access
- License scope
- Reviewed release artifacts and mandatory terms; not an assessment of training code or training data openness.
- Licenses
- Anthropic Commercial Terms of Service
- Boundary
- This record represents the Claude Fable 5 release identified by the dateless pinned ID claude-fable-5, the general-use safeguarded variant of the Mythos-class tier that sits above the Opus class. Anthropic's API, Amazon Bedrock, Google Cloud, Microsoft Foundry, Claude Platform on AWS, Claude applications, Claude Mythos 5, and later Fable releases remain separate service or product boundaries.
Risk statements
“ASL-3” · Safeguard standard
As with many previous models, we are treating Mythos 5 as CB-1 and applying ASL-3 protections to Fable 5, including blocking classifiers against CB-1 misuse.
- Risk areas
- Biological or chemical
- Covers
- Safeguards on a release channel
Read the developer's statement ↗ · 2026-10-07 · Research confidence: High
Anthropic states that this release ships under the “ASL-3” safeguard standard for biological or chemical capability. The statement covers safeguards on a release channel. This is the developer's own statement, not an Atlas risk rating.
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