One engineer runs multiple Claude Code sessions simultaneously, each in its own git worktree; repetitive verification work goes to subagents. The bottleneck shifts from 'writing code' to 'reviewing output.'
ThreadManager 持有 Arc<ThreadManagerState> 統管所有 thread，spawn_thread() 統一處理新建/恢復/分叉/子代理四種啟動路徑；ForkSnapshot 定義 TruncateBeforeNthUserMessage/Interrupted 兩種語義；AgentControl 透過 Weak<ThreadManagerState> 避免循環引用；agent_graph_store 追蹤 ThreadSpawnEdgeStatus::Open/Closed。
Mature subagents need roles, bounded fan-out, narrowed permissions, and a result contract. looplane now has native named-role schedules, parallel fan-out, child allowed_paths constrained by the parent, unsafe execution disabled by default, and parent-approved transaction proposals. Persistent background lifecycles, recursion trees, and automatic worktree merging remain open.
Attach enough MCP servers and the tool schemas alone eat your context — upstream's extreme example is Cloudflare's ~3,300 tools, whose names alone run about 32K tokens. Hermes answers with Tool Search: MCP and non-core plugin tools collapse into three bridge tools and schemas load on demand, while core tools never defer. Separately, plugins are disabled by default and only run when named in `plugins.enabled`.
There are already 6,400+ .claude/agents/*.md files on GitHub. We dissected 4 representative projects — ChemistryTimes (content production pipeline), claude-sub-agent (document-driven development pipeline), agentic (Temporal.io DAG parallel execution), and vs-copilot-multi-agent (hook-enforced memory persistence) — plus ruflo's enterprise-grade swarm architecture, distilling 6 design patterns and 5 practical trends.
Claude Code runs from $20/mo Pro to $200/mo Max 20x. Quota is a rolling five-hour window with weekly limits on top, shared across Claude on web, desktop, mobile, and the terminal. When you run out you can switch to usage credits at standard API rates rather than stopping.
A Skill is a prompt template you invoke manually. A Subagent is an independent agent that Claude routes to automatically. They look similar, but differ completely in trigger mechanism, tool isolation, and context management.