Thought I'd share this for folks as I was wondering about this for a while and got my hands dirty with Squad recently! I wrote an article too so I'll drop that in the comments threads!

TL;DR For the Busy Dev

• Fleet Mode (/fleet) is built into Copilot CLI. It auto-decomposes your task and runs stateless sub-agents in parallel. Zero setup. No memory between sessions.
• Squad is an open-source framework by Brady Gaster (Principal PM Architect at Microsoft). It installs a persistent team of named AI specialists into your repo. They remember decisions, enforce review protocols, and learn your codebase over time.
• They are different layers that solve different problems. Fleet is a dispatch primitive. Squad is a coordination framework built on top of the same sub-agent primitives.
• Squad is not redundant because of Fleet. Brady explicitly evaluated using Fleet as Squad's core and decided against it.
• They work better together. Squad v0.10.0 ships a hybrid dispatch mode that uses Fleet for read-heavy batch work (2.9x faster) and its own charter-aware dispatching for writes.
• Pick Fleet for one-off parallel tasks. Pick Squad for projects where agents need to accumulate knowledge over days or weeks. Pick both if you want the speed of Fleet and the governance of Squad.