2026-09-21-github-copilot-cli-capability-worktrees-out-of-experimental-fleet-custom-agents-read-repo-instructions

Capability: worktrees out of experimental, --fleet, custom agents read repo instructions. /worktree, /move, and --worktree work without experimental mode (1.0.85, L137); worktreePathTemplate controls where they go (1.0.87, L5). Custom agents can opt into AGENTS.md, copilot-instructions.md and CLAUDE.md with include-custom-instructions: true (1.0.86, L31). Plugin-contributed agents can be selected and run (1.0.85, L109). Docs describe --fleet for parallel sub-task fan-out from -p, not supported with --acp.

Channel: tagged-release (1.0.85, 1.0.86, 1.0.87); docs-only for --fleet. Half: capability. Date: 2026-09-15 to 2026-09-21.

Operator consequence: Try: parallel worktree sessions are now a supported path, not an experiment. --fleet is a doc claim with no version pin; confirm with copilot --help on your installed version before building CI on it.

Receipt

• https://github.com/github/copilot-cli/blob/c13b3dcae4f1/changelog.md?plain=1#L137
• https://github.com/github/docs/commit/d33e22cae269