Mythos-class model achieves strongest long-context reasoning and autonomous task execution; priced at $10/$50 per million tokens, half the cost of Mythos Preview.
June 10, 2026
Summary
Developers can now delegate multi-day codebase migrations and complex analytical tasks to a single model with improved token efficiency and vision capabilities. Extended context window (millions of tokens) with persistent memory enables autonomous agents to maintain state and self-correct across longer workflows.
Why it matters
Developers can now delegate multi-day codebase migrations and complex analytical tasks to a single model with improved token efficiency and vision capabilities. Extended context window (millions of tokens) with persistent memory enables autonomous agents to maintain state and self-correct across longer workflows.
Implementation verdict
Replaces Opus 4.8 for code generation, knowledge work, and vision tasks—available now at public pricing. Requires updating inference clients to handle extended context and autonomous loops. Worth adopting immediately for long-horizon coding tasks (50M-line migrations tested); vision-only mode replaces scaffolded harnesses. Mythos 5 (unrestricted version) limited to trusted access program initially.
Sources
Dev Signal
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