Using Claude Mythos 5.1 on Microsoft Foundry
Implementation guide · Claude Mythos · Anthropic
Microsoft Foundry exposes Claude Mythos 5.1 through model ID claude-mythos-5-1. Use the setup steps, sourced pricing, capabilities, and official provider links below to validate this route before deployment.
Last refreshed 2026-09-01. Next refresh: weekly.
Quick Start
- 1
- 2Use the Microsoft Foundry SDK or REST API to call
claude-mythos-5-1— see the documentation for request format. - 3
Code Examples
Pricing on Microsoft Foundry
| Type | Price (per 1M) |
|---|---|
| Input tokens | $10.00 |
| Output tokens | $50.00 |
Capabilities
About Claude Mythos 5.1
Anthropic's invitation-only Mythos-class model, released September 1, 2026. Same underlying model as Claude Fable 5.1 without the cybersecurity and biology safeguards. Access is limited to a small set of vetted organizations through trusted access / Project Glasswing; Anthropic currently makes it available to a set of US organizations and is working to expand. Claude API id claude-mythos-5-1. Pricing starts at $10 per 1M input tokens and $50 per 1M output tokens (limited availability; no cheaper public tier published). Cache reads $0.25 per 1M. 1M-token context, 128K max output, adaptive thinking always on, text and image input to text output.