claude_code_releases · May 28, 2026 · release
v2.1.154
What's changed Opus 4.8 is here! Now defaults to high effort · /effort xhigh for your hardest tasks Introducing dynamic workflows: ask Claude to create a workflow and it orchestrates work across tens to hundreds of agents in the background, so you can take on larger, more complex tasks. Run /workflows to view your runs Fast mode on Opus 4.8 is now available at a fraction of its previous cost: 2x the standard rate for 2.5x the speed The lean system prompt is now the default for all models except Haiku, Sonnet, and Opus 4.7 and earlier Claude now reserves the multiple-choice question prompt for decisions it genuinely cannot make itself, instead of asking when it already has enough context to proceed /simplify now runs a cleanup-only review (reuse, simplification, efficiency, altitude) and applies the fixes, instead of running the full /code-review --fix bug-hunting review Renamed the /effort slider labels from "Speed"/"Intelligence" to "Faster"/"Smarter" for clarity claude agents : type ! to run a shell command as a background session you can attach to and detach from. Also available as claude --bg --exec ' ' claude agents : /logout now signs you out instead of being sent to a background session ←← to open the agents view now works on Bedrock, Vertex, Foundry, and with telemetry disabled Claude in Chrome: pick which connected browser to use via /chrome → "Select browser…", or in-chat when a browser action runs with multiple connected Plugins can now declare defaultEnabled: fals