The first rung of running a fleet instead of a session: promote one Claude Code session to a lead that dispatches waves of subagents, which work in parallel and report back. **The tutorial.** The orchestrator-worker pattern, drawn from Anthropic's [multi-agent research system writeup](https://www.anthropic.com/engineering/multi-agent-research-system) (Opus lead plus Sonnet workers beat single-agent Opus by ~90%, at roughly 15x the tokens of a chat, with effort scaled to query complexity). How it maps onto Claude Code today: the [Agent tool](https://code.claude.com/docs/en/sub-agents) (renamed from Task in v2.1.63) spawns workers in their own context windows that return only a summary; the two-level limit (subagents can't spawn subagents, so "waves" are batches); foreground vs background workers and Ctrl+B. Writing a custom subagent in your project's `agents` folder, with the frontmatter that turns earlier episodes' cost levers into per-worker dials: `model` (Sonnet/Haiku workers under an Opus lead), `maxTurns`, `effort`, `tools`, `skills`, `mcpServers`, and `isolation: worktree` (the callback to last episode's worktrees). A worked fan-out migration: Explore to map files, partition by file ownership, complete delegation prompts, structured returns, and a synthesis-and-test stage, plus the packaged [`/batch`](https://code.claude.com/docs/en/agents) skill (5-30 worktree subagents, a PR each). Where it scales next: [agent teams](https://code.claude.com/docs/en/agent-teams) and dynamic workflows. **The pitfall: token blowup from over-orchestrating**, with the blank-context worker, file collisions, and the lead losing the thread underneath it. How to recognize each on `/usage` and `/context`, and how to bound it. The rule: orchestrate for breadth and independence, stay single-agent for depth and coupling. **News.** Claude Code 2.1.162 (June 3): a `waitingFor` field in the agents JSON, Read deny rules now hide files from Glob/Grep, and Windows path-matching fixes ([changelog](https://code.claude.com/docs/en/changelog)). API changes June 2: no billing on zero-output refusals and a `max_tokens` cap on the advisor tool ([release notes](https://platform.claude.com/docs/en/release-notes/overview)). Earlier episodes referenced: subagents, skills, CLAUDE.md, context windows, MCP servers, cost and rate-limit engineering, and parallel sessions with git worktrees.