Identity
- Status
- active
- Developer ID
claude-mythos-5-1- Released
- Sep 1, 2026
- Version
- Claude Mythos 5.1
- License
- Unknown
AnthropicClaude Mythos 5.1
Claude Mythos 5.1 is the invitation-only Project Glasswing version of Claude Fable 5.1 for approved cybersecurity and life-sciences work.
- Token context
- 1,000K tokens
- Inputs
- Text, Image
- Outputs
- Text
- Released
- Sep 1, 2026
Providers & Pricing
Estimate workload cost →| Provider | Input / 1M | Output / 1M | Cache read / 1M | Cache write / 1M | Observed | Evidence |
|---|---|---|---|---|---|---|
AnthropicAvailable | $10.00 | $50.00 | $0.25 | $12.50 | Sep 2, 2026 | Provider-reported |
At a Glance
Model Facts
Capacity
- Token context
- 1,000K tokens
- Maximum output
- 128K tokens
- Total parameters
- Unknown
- Active parameters
- Unknown
- Knowledge cutoff
- Jun 1, 2026
Interface and Access
- Inputs
- Text, Image
- Outputs
- Text
- API available
- Yes
- Open weights
- No
- Self-hostable
- No
- Reasoning
- Yes
- Vision
- Yes
- Tool calling
- Yes
- Capabilities
- chat, generation, reasoning, tools
This page represents one developer model product. Dated API snapshots, serving endpoints, pricing, regions, quantizations, and service tiers attach as versioned aliases or provider details and never create duplicate public model records.
Version Lineage
PredecessorUnknown
SuccessorsUnknown
Aliasesclaude-mythos-5-1
Explicit Unknowns
- Architecture
- Tokenizer
Primary Evidence
Sources and Observation Date
Comparable Peers
Related Model Comparisons
| A | Pair | B | Context |
|---|---|---|---|
Claude Mythos 5.1Anthropic | vs | Claude Fable 5.1Anthropic | family variantsimage, text |
Claude Mythos 5.1Anthropic | vs |  Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Claude Mythos 5.1Anthropic | vs | Grok 4.6xAI | cross-developer peersimage, text |
Claude Mythos 5.1Anthropic | vs |  Kimi K3Moonshot AI | cross-developer peersimage, text |
Claude Mythos 5.1Anthropic | vs | Claude Sonnet 5Anthropic | family variantsimage, text |
Claude Mythos 5.1Anthropic | vs | Gemini 3.8 Flash CyberGoogle DeepMind | cross-developer peerstext |
Claude Mythos 5.1Anthropic | vs | Claude Fable 5Anthropic | family variantsimage, text |
Claude Mythos 5.1Anthropic | vs | Claude Opus 5Anthropic | family variantsimage, text |
Claude Mythos 5.1Anthropic | vs |  GPT-4.1 NanoOpenAI | cross-developer peersimage, text |
Claude Mythos 5.1Anthropic | vs | GPT-5.6 SolOpenAI | cross-developer peersimage, text |
Claude Mythos 5.1Anthropic | vs |  Qwen3.7 MaxQwen | cross-developer peersimage, text |
Claude Mythos 5.1Anthropic | vs | Grok 4.3xAI | cross-developer peersimage, text |
Questions
Claude Mythos 5.1 FAQs
What is Claude Mythos 5.1?+
Claude Mythos 5.1 is the invitation-only Project Glasswing version of Claude Fable 5.1 for approved cybersecurity and life-sciences work. It is developed by Anthropic and its current sourced lifecycle status is active.
What inputs and outputs does Claude Mythos 5.1 support?+
Claude Mythos 5.1's current record lists Text and Image as input and Text as output.
How much context does Claude Mythos 5.1 support?+
The current record lists a 1,000K-token context window and a maximum output of 128K tokens.
Is Claude Mythos 5.1 available through an API?+
Claude Mythos 5.1 is marked as API-available. The directly sourced provider records currently include Anthropic.
How much does Claude Mythos 5.1 cost through an API?+
The lowest directly sourced prices currently attached to Claude Mythos 5.1 are $10.00 per million input tokens through Anthropic and $50.00 per million output tokens through Anthropic. Prices are provider-specific and should be checked against each cited observation date.
What capabilities and tasks does Claude Mythos 5.1 support?+
Claude Mythos 5.1's recorded capabilities are chat, generation, reasoning, and tools. Its supported tasks are image and text.
Can Claude Mythos 5.1 be self-hosted?+
Claude Mythos 5.1 is not marked as an open-weight model. Self-hosting is marked as unsupported, with no license recorded.
Does Claude Mythos 5.1 have related versions or aliases?+
No predecessor is recorded. No successor is recorded. Recorded aliases are claude-mythos-5-1.
Which models can Claude Mythos 5.1 be compared with?+
The current compatible peer set includes Claude Fable 5.1, Gemini 3.1 Pro, Grok 4.6, Kimi K3, and Claude Sonnet 5. Compatibility requires shared sourced modalities and tasks; it does not imply that one model is better. Browse model comparisons →
How current is the Model Markets record for Claude Mythos 5.1?+
Claude Mythos 5.1 was last verified Sep 2, 2026 from Anthropic's primary source, “Claude Mythos 5.1 | Claude Platform Docs.” The evidence is classified as official fact.