## What
This change introduces a new `ReadOnlyAccess` model and threads it through
sandbox policy consumers so read access is explicit instead of implicit.
- Added `ReadOnlyAccess` to protocol:
- `Restricted { include_platform_defaults, readable_roots }`
- `FullAccess`
- Changed `SandboxPolicy` shape:
- `ReadOnly` is now `ReadOnly { access: ReadOnlyAccess }`
- `WorkspaceWrite` now carries `read_only_access: ReadOnlyAccess`
- Kept existing behavior for now by defaulting to `ReadOnlyAccess::FullAccess`
in constructors and current config/app-server mappings.
- Added helper methods to compute effective readable roots (including optional
platform defaults + cwd) and to detect full read access.
- Updated seatbelt policy generation to honor restricted read roots by emitting
scoped `(allow file-read* ...)` entries when full read access is not granted.
- Updated Linux backends (`bwrap`, legacy landlock path) to fail closed with an
explicit `UnsupportedOperation` when restricted read access is requested but
not yet implemented there.
- Updated Windows sandbox backends (standard, elevated, and runner paths) to
fail closed in the same way for restricted read access.
- Updated all call sites/tests/pattern matches for the new structured variants
and regenerated app-server protocol schema/types.
## Why
The previous `SandboxPolicy::ReadOnly` implied full-disk read access and left
no way to express a narrower read surface.
This refactor establishes the policy model needed to support user-configurable
read restrictions in a follow-up without changing current runtime behavior.
It also ensures we do not silently ignore future restricted-read policies on
platform backends that do not support them yet. Failing closed keeps sandbox
semantics predictable and avoids accidental over-permission.
## Compatibility and rollout notes
- Existing behavior is preserved by default (`FullAccess`).
- Existing config/app-server flows continue to serialize/deserialize cleanly.
- New schema artifacts are included to keep generated protocol outputs in sync.
## Validation
- `just fmt`
- `just fix -p codex-protocol -p codex-core -p codex-linux-sandbox -p codex-windows-sandbox -p codex-app-server-protocol`
- `cargo check -p codex-windows-sandbox`
- Targeted crate/test runs were executed during development for protocol/core/
sandbox-related crates.
This adds support for `allowed_sandbox_modes` in `requirements.toml` and
provides legacy support for constraining sandbox modes in
`managed_config.toml`. This is converted to `Constrained<SandboxPolicy>`
in `ConfigRequirements` and applied to `Config` such that constraints
are enforced throughout the harness.
Note that, because `managed_config.toml` is deprecated, we do not add
support for the new `external-sandbox` variant recently introduced in
https://github.com/openai/codex/pull/8290. As noted, that variant is not
supported in `config.toml` today, but can be configured programmatically
via app server.
Constrain `approval_policy` through new `admin_policy` config.
This PR will:
1. Add a `admin_policy` section to config, with a single field (for now)
`allowed_approval_policies`. This list constrains the set of
user-settable `approval_policy`s.
2. Introduce a new `Constrained<T>` type, which combines a current value
and a validator function. The validator function ensures disallowed
values are not set.
3. Change the type of `approval_policy` on `Config` and
`SessionConfiguration` from `AskForApproval` to
`Constrained<AskForApproval>`. The validator function is set by the
values passed into `allowed_approval_policies`.
4. `GenericDisplayRow`: add a `disabled_reason: Option<String>`. When
set, it disables selection of the value and indicates as such in the
menu. This also makes it unselectable with arrow keys or numbers. This
is used in the `/approvals` menu.
Follow ups are:
1. Do the same thing to `sandbox_policy`.
2. Propagate the allowed set of values through app-server for the
extension (though already this should prevent app-server from setting
this values, it's just that we want to disable UI elements that are
unsettable).
Happy to split this PR up if you prefer, into the logical numbered areas
above. Especially if there are parts we want to gavel on separately
(e.g. admin_policy).
Disabled full access:
<img width="1680" height="380" alt="image"
src="https://github.com/user-attachments/assets/1fb61c8c-1fcb-4dc4-8355-2293edb52ba0"
/>
Disabled `--yolo` on startup:
<img width="749" height="76" alt="image"
src="https://github.com/user-attachments/assets/0a1211a0-6eb1-40d6-a1d7-439c41e94ddb"
/>
CODEX-4087
helpful in the future if we want more granularity for requesting
escalated permissions:
e.g when running in readonly sandbox, model can request to escalate to a
sandbox that allows writes
In this PR, I am exploring migrating task kind to an invocation of
Codex. The main reason would be getting rid off multiple
`ConversationHistory` state and streamlining our context/history
management.
This approach depends on opening a channel between the sub-codex and
codex. This channel is responsible for forwarding `interactive`
(`approvals`) and `non-interactive` events. The `task` is responsible
for handling those events.
This opens the door for implementing `codex as a tool`, replacing
`compact` and `review`, and potentially subagents.
One consideration is this code is very similar to `app-server` specially
in the approval part. If in the future we wanted an interactive
`sub-codex` we should consider using `codex-mcp`
Michael Bolin