AnthropicAIWS category: AI ModelRestricted access
Claude Mythos 5.1
Restricted-access deployment sharing Claude Fable 5.1 capabilities for vetted Project Glasswing participants.
Facts Verified
Sep 1, 2026
Verification
Verified
Profile
Source-backed
Context
1M tokens
Max output
128K tokens
Specifications
Context
1M tokens
Max output
128K tokens
CompanyAnthropic
Release DateSep 1, 2026
Provider statusRestricted access
LicenseNot published
API availabilityNot published
Capability Map
Verified fieldsReasoning
Supported
Image input
Supported
Audio input
Not supported
Video input
Not supported
Native input modalities
TextImages
Native output: Text
Native output is what the model returns directly. Tool capabilities are separate.
Developer API Rates
Verified public rateInput / 1M
$10.00
Output / 1M
$50.00
Cached $0.2500 / 1M
Key Strengths
- Sensitive-domain research
- Long-horizon agentic work
- Scientific research
Limitations & Trade-offs
- Not generally available
- Restricted to vetted participants