Overview
- Claude Opus 4.8, released Friday, May 29, 2026, is available in research preview on Max, Team and Enterprise plans and via the Claude API and major cloud platforms with the same token pricing as Opus 4.7.
- Anthropic says Opus 4.8 is roughly four times less likely than Opus 4.7 to let code flaws pass unflagged because it proactively signals uncertainty and questions sketchy inputs.
- The release adds Dynamic Workflows for Claude Code that plan tasks, spawn and manage hundreds of parallel subagents, and self-verify outputs; Anthropic demonstrated a 750,000-line code migration completed in 11 days with a 99.8% test pass rate.
- New controls let users trade speed for deeper reasoning through an effort setting and let developers inject or change system instructions mid-task through the Messages API; Databricks reported about a 61% token-cost drop on its workloads using Opus 4.8.
- Anthropic said it will broaden access to more powerful Mythos-class models that are now tested under Project Glasswing once extra cybersecurity safeguards are in place, a move that could speed enterprise adoption but also raise supplier concentration and regulatory scrutiny.