Claude Code 2.1.163 to 2.1.197 brought major model upgrades, improved agent capabilities, and streamlined configuration options throughout June.
Models and Providers
- Claude Sonnet 5 as default: Now the default model with native 1-million-token context window and promotional pricing through August 31.
- Claude Fable 5 access: Mythos-class model with capabilities exceeding all previously available models, available in version 2.1.170 and later.
- Fallback models: Specify up to three backup models to use automatically when your primary model is overloaded or unavailable.
- Organization default models: Admins can set a preferred model in the org console, displayed in the model selector when you haven't chosen one.
Agents and Automation
- Nested sub-agents: Sub-agents can now spawn their own sub-agents up to five levels deep for more complex multi-agent workflows.
- Sub-agent permission prompts: Background subagents show permission prompts in your main session with the requesting agent named, letting you deny individual tools by pressing Esc.
Interface and Workflow
- /config command: Set any configuration option directly from the prompt using key=value syntax in interactive mode, batch processing, and Remote Control.
- /rewind support: Resume a conversation from before you ran /clear, recovering your previous context and work.
- Plugin management: /plugin list command displays installed plugins with optional filters, and a search bar was added to the plugin marketplace.
- MCP server authentication: CLI login and logout with headless support via --no-browser for SSH sessions.
Some other features were also released this month but are not listed here.