sandbox_workspace_write.network_access

network_access lives under the [sandbox_workspace_write] table in ~/.codex/config.toml. It only does anything when sandbox_mode = "workspace-write"; read-only mode blocks writes anyway, and danger-full-access skips the sandbox entirely.

Values

Value	What happens
false (default)	Sandboxed commands get no outbound network. npm install, pip install, curl all fail.
true	Sandboxed commands can reach the network. Filesystem limits still apply.

sandbox_mode = "workspace-write"

[sandbox_workspace_write]
network_access = true

Sibling keys in the same table: exclude_slash_tmp and exclude_tmpdir_env_var (both boolean, both default false) pull /tmp and $TMPDIR out of the writable set, and writable_roots adds extra writable paths. All four are on the official reference.

When to change it

1. Package installs fail inside a Codex session while the exact same command works in your own terminal. That is the classic tell the sandbox is blocking outbound traffic.
2. Test suites or scripts that hit an API fail with connection errors. Same fix.
3. Try it as a one-off before committing: codex -c sandbox_workspace_write.network_access=true uses the documented -c override and only affects that session.

If you were about to set sandbox_mode = "danger-full-access" just to get npm install working, set this key instead. You keep the filesystem fence and lose nothing you needed.

Gotchas

• The Codex desktop app has ignored this key while the CLI honored it (#13373). If the app still blocks network after you set true, you hit a known bug, and the workaround discussion is in that thread.
• On Windows, users report DNS resolution failing in the sandbox even with network enabled (#18675).
• true is all-or-nothing, with no domain allowlist on this key. For filtered outbound traffic, Vaughan’s proxy writeup covers the permission-profile route with per-domain allow and deny rules (deny wins on conflict).
• The reference doesn’t say whether flipping this changes approval prompting. From the docs alone, it opens the network and nothing else.

Related settings

• sandbox_mode picks which sandbox this table applies to.
• approval_policy controls when Codex asks before running commands at all.
• Landed here from the “retry without sandbox” error? The fix page is at /errors/sandbox-error-retry-without-sandbox/.