Claude Code v2.1.175 → v2.1.177: nested subagents enable multi-tier parallel delegation

[claude-yolo]

WHY you should care

🚀 Nested subagents — subagents can now spawn their own subagents (up to 5 levels deep for background agents, unlimited for foreground). This means complex multi-tier delegation patterns work without routing everything through the main conversation.

Also shipped:

• resolvedModel field on AgentOutput and hook tool_response — finally know what model a subagent actually ran on (not just what you requested)
• skipMcpDiscovery flag for SDK plugin config — skip MCP server discovery on a per-plugin basis
• Session titles now generated in conversation language
• footerLinksRegexes setting for regex-matched footer badges
• Better Bedrock credential caching (respects actual expiry instead of fixed 1h)
• Fixes: availableModels enforcement, hook if conditions for file paths, Linux sandbox with symlinked settings, tmux clipboard, Remote Control edge cases, background session stability

Links

• Docs PR: docs: Claude Code v2.1.177 - nested subagents, resolvedModel field, SDK plugin skipMcpDiscovery claude-code-docs#1042
• Full changelog: https://github.com/thevibeworks/claude-code-docs/blob/main/content/en/docs/claude-code/changelog.md

/cc @lroolle