20. Teams, Sessions and Worktrees (Four Ways to Run AI Work in Parallel)

In Episode 20 of Beyond Prompting, author Sho Shimoda clarifies how to run multiple AI tasks concurrently without getting tangled in state or disk conflicts. While Chapter 19 focused on subagents, Chapter 20 introduces three other mechanisms for parallelism, organizing all four around what gets separated: context, attention, whole sessions, or files. In this episode, we cover:

• The Four Parallelism Mechanisms: Distinguishing between Subagents (separates context window), Background Sessions (separates attention), Agent Teams (separates whole sessions), and Git Worktrees (separates working tree files).
• Teammates vs. Subagents: Why teammates in an agent team operate as peer sessions that message each other and share a task list rather than reporting upward to a caller, and why coordination costs mean most tasks are better served by a well-specified single session.
• Cross-Session Messaging: Using /list-agents and SendMessage to let active terminal sessions communicate across project boundaries, governed by the crossSessionInbound setting.
• Worktrees for File Collisions: Creating isolated Git checkouts with claude --worktree <name> so parallel sessions don't overwrite each other's files on disk, and copying ignored local environment files using .worktreeinclude.
• Managing Parallel Load: Using the agent view (claude agents) to monitor background execution, and understanding why parallel worktrees and agent teams carry separate prompt caches.

(Note for listeners: This episode covers Chapter 20 of Sho Shimoda's book RUNNING CLAUDE: The Operator’s Guide to Chat, Cowork and Claude Code, available on Amazon as the successor book to Master Claude: Chat, Cowork and Code).