Important
Re-verified against Xcode 27.0 beta (build 27A5194q) on 2026-06-16. The defaults below still exist, but the agent launch path and the external-agent approval flow both changed since 26.3. See What changed in 27.0 and the external-agent test.
Note
This covers "how to let Xcode's own agent reach outside itself without prompting." It does not solve the reverse: getting a terminal agent to drive Xcode without the per-launch prompt. That one is still open; see the bottom.
Setting this is the moral equivalent of claude --dangerously-skip-permissions, so weigh it accordingly.