codex - 💡(How to fix) Fix Expose server-level MCP approval defaults in codex mcp add

Summary

mcp_servers.<id>.default_tools_approval_mode is supported in config, but codex mcp add cannot set it. That leaves scripted/noninteractive setups hand-editing TOML, and JSON readbacks do not expose the server-level default.

Proposed change

Add:

codex mcp add <name> --default-tools-approval-mode <auto|prompt|approve> -- <command> [args...]

The flag would persist the existing default_tools_approval_mode field. codex mcp get --json and codex mcp list --json would include it so setup scripts can verify the result. Existing defaults and runtime approval precedence are unchanged.

Ready patch

I prepared and tested a minimal branch:

• Branch: https://github.com/VrtxOmega/codex/tree/codex/mcp-add-default-approval-mode
• Commit: https://github.com/VrtxOmega/codex/commit/80afa2eb37
• Compare: https://github.com/openai/codex/compare/main...VrtxOmega:codex%2Fmcp-add-default-approval-mode

I tried to open this as a pull request, but GitHub shows: "An owner of this repository has limited the ability to open a pull request to users that are collaborators on this repository." Filing this issue so the tested patch is visible and easy to cherry-pick or recreate.

Tests run

PATH=/home/rage/.cargo/bin:$PATH just test -p codex-cli --test mcp_add_remove
PATH=/home/rage/.cargo/bin:$PATH just fix -p codex-cli
git diff --check
PATH=/home/rage/.cargo/bin:$PATH cargo fmt --check -- --config imports_granularity=Item

The targeted CLI integration test passed, including valid persistence/readback and invalid-mode rejection. cargo fmt --check exited 0, with stable rustfmt warning that imports_granularity = Item is nightly-only.

Note: just fmt completed the Rust formatting phase, then failed in the Python SDK ruff phase because openai-codex-cli-bin==0.132.0 has no Linux glibc wheel for this platform. No SDK files were changed.

Related: #24135 and #13476. This is a narrow CLI/config surface improvement, not a complete resolution of all runtime MCP approval behavior.