OpenMythos is a from-scratch attempt to reconstruct the architecture behind Claude Mythos, the cyber-capable model Anthropic refuses to release. It's speculation in code form.
A new open-source script swaps Claude Code's expensive Anthropic backend for DeepSeek V4 Pro, OpenRouter, or Fireworks AI—keeping the agent loop, slashing the bill.
NIST's CAISI evaluated DeepSeek V4 Pro using private benchmarks and a cost-comparison filter that excluded every US model except GPT-5.4 mini. Critics call the methodology convenient.