MCP servers of type 'sdk' in config files are now rejected unless registered by the SDK itself
An MCP server declared with type "sdk" in a configuration file is now explicitly rejected with a dedicated error, unless the configuration comes from the in-process SDK (marked as source dynamic). The general "unknown server type" error message also no longer lists sdk as a valid type unless the source is dynamic.
This closes off a way of declaring an sdk-type server that only an SDK host application should be able to register, giving a clearer error instead of letting it fail as a generic unknown type.
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
For long-running agentic tasks, the TypeScript and Ruby tool runners support automatic [compaction](https://platform.claude.com/docs/en/build-with-claude/context-editing#client-side-compaction-sdk), which generates summaries when token usa…agents-and-tools/tool-use/tool-runner see the edit
You tried to switch [output styles](/docs/en/output-styles) with `/output-style <style>` or `/config outputStyle=<style>` in a session whose setting sources exclude `local`. Examples are an [Agent SDK](/docs/en/agent-sdk/typescript) sessio…errors see the edit
Anthropic's documentation has since written up sdk, on Error reference.