Claude Mythos 5
Anthropic · released 2026-08-21 · proprietary (API-only; access currently restricted to Enterprise Claude Security scans and cybersecurity partners under the Cyber Verification Program, not general availability) · announcement
Price
unknown — not published, or the API model id isn't known yet.
Context window
unknown (not stated on the announcement page)
Rate limits
no matching rate-limit entry for this model on Anthropic's published table yet. full rate-limit reference
Retirement
no retirement announced.
Runs on
no merged support PR yet on the runtimes AI Squawk watches (vLLM, llama.cpp, transformers, SGLang, Ollama), and not on the Ollama library.
Provider status
up no open incidents at Anthropic · full scoreboard
Latest mentions
- RELEASE Fable and Mythos 5.2: The System Card
— It’s that time again: Introducing the world’s most powerful model, Claude Mythos 5.2. · 2d ago
- OUTAGE Anthropic: Elevated errors for Claude Mythos 5.1 and… — claude.ai, Claude API (api.anthropic.com) +2
— The issue affecting Claude Mythos 5.1 and Claude Fable 5.1 has been resolved. · 40d ago
- OUTAGE Anthropic: Intermittent error spikes for Claude Mythos 5.1 and Claude Fable 5.1
— We are investigating elevated errors on requests to Claude Mythos 5.1 and Claude Fable 5.1. We will provide an update as soon as possible. · 60d ago
- OUTAGE Anthropic: Elevated errors for Claude Mythos 5.1 and… — claude.ai, Claude API (api.anthropic.com) +2
— The issue affecting Claude services has been resolved. · 64d ago
- OUTAGE Anthropic: Elevated errors for multiple models — claude.ai, Claude API (api.anthropic.com) +2
— The issue affecting Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 has been resolved. · 72d ago
- RELEASE Claude Fable 5.1 and Claude Mythos 5.1
— Anthropic released Claude Fable 5.1 and Claude Mythos 5.1, which share base weights but differ in safeguards and routing… · 74d ago
- RELEASE Bringing the cybersecurity capabilities of Claude Mythos 5 to more defenders
— We're sharing an update on our efforts to help more teams use frontier capabilities for cyber defense. · 85d ago
- OUTAGE Anthropic: Elevated errors for Claude Mythos 5, Claud… — claude.ai, Claude API (api.anthropic.com) +2
— The issue affecting Claude Mythos 5 and Claude Fable 5 has been resolved. · 93d ago
- OUTAGE Anthropic: Elevated errors for Mythos 5, Fable 5, Opu… — claude.ai, Claude API (api.anthropic.com) +2
— We are investigating elevated errors on requests to Claude Mythos 5, Claude Fable 5, and Claude Haiku 4.5. We will provide an update as soon as possible. · 111d ago