## Why
`ThreadSessionState` is the TUI's cached view of an app-server session.
To make `PermissionProfile` the canonical runtime permissions model,
cached thread sessions need to always have a profile instead of treating
the profile as an optional supplement to a legacy `sandbox` response
field.
The main compatibility concern is older app-server v2 lifecycle
responses that only include `sandbox` and omit `permissionProfile`:
- `thread/start` -> `ThreadStartResponse.sandbox`
- `thread/resume` -> `ThreadResumeResponse.sandbox`
- `thread/fork` -> `ThreadForkResponse.sandbox`
Those responses must still hydrate correctly when the TUI is pointed at
an older app-server. This PR converts the legacy `sandbox` value into a
`PermissionProfile` immediately at response ingestion time, using the
response `cwd`, so cached sessions do not carry an optional profile that
can later reinterpret cwd-bound grants against a different thread cwd.
This fallback is intentionally boundary compatibility. The follow-up PRs
in this stack continue the cleanup by making `SessionConfiguredEvent`
profile-only, deriving sandbox projections from snapshots only when an
API still needs them, and then removing `sandbox_policy` from
`ThreadSessionState`.
## What Changed
- Makes `ThreadSessionState.permission_profile` required.
- Converts legacy app-server response `sandbox` values into a
`PermissionProfile` at ingestion time using the response cwd.
- Ensures `thread/read` hydration does not reuse a primary session
profile that may be anchored to a different cwd; it uses the active
widget permission settings for the read thread fallback instead of
reusing cached primary-session permissions.
- Keeps the app-server request path unchanged: embedded sessions send
profiles, while remote sessions continue using legacy sandbox overrides
for compatibility.
## Verification
- `cargo test -p codex-tui thread_read --lib`
- `cargo test -p codex-tui
permission_settings_sync_preserves_active_profile_only_rules --lib`
- `cargo test -p codex-tui
resume_response_restores_turns_from_thread_items --lib`
- `cargo test -p codex-tui thread_session_state::tests --lib`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/19773).
* #19900
* #19899
* #19776
* #19775
* #19774
* __->__ #19773
## Summary
- Remove `ghost_snapshot` / `GhostCommit` from the Responses API surface
and generated SDK/schema artifacts.
- Keep legacy config loading compatible, but make undo a no-op that
reports the feature is unavailable.
- Clean up core history, compaction, telemetry, rollout, and tests to
stop carrying ghost snapshot items.
## Testing
- Unit tests passed for `codex-protocol`, `codex-core` targeted undo and
compaction flows, `codex-rollout`, and `codex-app-server-protocol`.
- Regenerated config and app-server schemas plus Python SDK artifacts
and verified they match the checked-in outputs.
## Why
Recent `main` CI had repeated flakes in the plugin fixture tests:
- `codex-core::all
suite::plugins::explicit_plugin_mentions_inject_plugin_guidance` failed
in runs
[24909500958](https://github.com/openai/codex/actions/runs/24909500958),
[24908076251](https://github.com/openai/codex/actions/runs/24908076251),
[24906197645](https://github.com/openai/codex/actions/runs/24906197645),
and
[24898949647](https://github.com/openai/codex/actions/runs/24898949647).
- `codex-core::all suite::plugins::plugin_mcp_tools_are_listed` failed
in runs
[24909500958](https://github.com/openai/codex/actions/runs/24909500958),
[24908076251](https://github.com/openai/codex/actions/runs/24908076251),
and
[24898949647](https://github.com/openai/codex/actions/runs/24898949647).
The failures were in the same plugin/MCP fixture family: assertions
expected sample plugin guidance or tool inventory, but the test could
observe the session before the sample MCP server had finished startup.
## Root Cause
`explicit_plugin_mentions_inject_plugin_guidance` submitted the user
turn immediately after constructing the session. MCP startup is
asynchronous, so on a slower or busier CI runner the prompt could be
built before the sample plugin MCP server had reported its tools. That
made the test depend on scheduler timing rather than the fixture being
ready.
`plugin_mcp_tools_are_listed` already needed the same readiness
condition, but its wait logic was local to that test.
## What Changed
- Added a shared `wait_for_sample_mcp_ready` helper for the plugin
fixture tests.
- Wait for `McpStartupComplete` before submitting the explicit plugin
mention turn.
- Reuse the same readiness helper in the MCP tool-listing test.
## Why This Should Be Reliable
The tests now wait for the explicit readiness signal from the sample MCP
server before asserting guidance or tools derived from that server. This
removes the startup race while still exercising the real fixture path,
so the assertions should only run after the plugin inventory is
deterministic.
## Verification
- `cargo test -p codex-core --test all plugins::`
- GitHub CI for this PR is passing.
## Summary
- Extracted the shared filesystem types and `ExecutorFileSystem` trait
into a new `codex-file-system` crate
- Switched `codex-config` and `codex-git-utils` to depend on that crate
instead of `codex-exec-server`
- Kept `codex-exec-server` re-exporting the same API for existing
callers
## Testing
- Ran `cargo test -p codex-file-system`
- Ran `cargo test -p codex-git-utils`
- Ran `cargo test -p codex-config`
- Ran `cargo test -p codex-exec-server`
- Ran `just fix -p codex-file-system`, `just fix -p codex-git-utils`,
`just fix -p codex-config`, `just fix -p codex-exec-server`
- Ran `just fmt`
- Updated and verified the Bazel module lockfile
## Summary
Disallow fileParams metadata for custom MCPs
Restricts Codex openai/fileParams handling to the first-party codex_apps
MCP server. Custom MCP servers may still advertise the metadata, but
Codex now ignores it for upload rewriting, preventing non-Apps tools
from receiving signed OpenAI file refs for local paths. Added a
regression test for the allowed and denied cases.
## Why
This continues the permissions migration by making legacy config default
resolution produce the canonical `PermissionProfile` first. The legacy
`SandboxPolicy` projection should stay available at compatibility
boundaries, but config loading should not create a legacy policy just to
immediately convert it back into a profile.
Specifically, when `default_permissions` is not specified in
`config.toml`, instead of creating a `SandboxPolicy` in
`codex-rs/core/src/config/mod.rs` and then trying to derive a
`PermissionProfile` from it, we use `derive_permission_profile()` to
create a more faithful `PermissionProfile` using the values of
`ConfigToml` directly.
This also keeps the existing behavior of `sandbox_workspace_write` and
extra writable roots after #19841 replaced `:cwd` with `:project_roots`.
Legacy workspace-write defaults are represented as symbolic
`:project_roots` write access plus symbolic project-root metadata
carveouts. Extra absolute writable roots are still added directly and
continue to get concrete metadata protections for paths that exist under
those roots.
The platform sandboxes differ when a symbolic project-root subpath does
not exist yet.
* **Seatbelt** can encode literal/subpath exclusions directly, so macOS
emits project-root metadata subpath policies even if `.git`, `.agents`,
or `.codex` do not exist.
* **bwrap** has to materialize bind-mount targets. Binding `/dev/null`
to a missing `.git` can create a host-visible placeholder that changes
Git repo discovery. Binding missing `.agents` would not affect Git
discovery, but it would still create a host-visible project metadata
placeholder from an automatic compatibility carveout. Linux therefore
skips only missing automatic `.git` and `.agents` read-only metadata
masks; missing `.codex` remains protected so first-time project config
creation goes through the protected-path approval flow. User-authored
`read` and `none` subpath rules keep normal bwrap behavior, and `none`
can still mask the first missing component to prevent creation under
writable roots.
## What Changed
- Adds profile-native helpers for legacy workspace-write semantics,
including `PermissionProfile::workspace_write_with()`,
`FileSystemSandboxPolicy::workspace_write()`, and
`FileSystemSandboxPolicy::with_additional_legacy_workspace_writable_roots()`.
- Makes `FileSystemSandboxPolicy::workspace_write()` the single legacy
workspace-write constructor so both `from_legacy_sandbox_policy()` and
`From<&SandboxPolicy>` include the project-root metadata carveouts.
- Removes the no-carveout `legacy_workspace_write_base_policy()` path
and the `prune_read_entries_under_writable_roots()` cleanup that was
only needed by that split construction.
- Adds `ConfigToml::derive_permission_profile()` for legacy sandbox-mode
fallback resolution; named `default_permissions` profiles continue
through the permissions profile pipeline instead of being reconstructed
from `sandbox_mode`.
- Updates `Config::load()` to start from the derived profile, validate
that it still has a legacy compatibility projection, and apply
additional writable roots directly to managed workspace-write filesystem
policies.
- Updates Linux bwrap argument construction so missing automatic
`.git`/`.agents` symbolic project-root read-only carveouts are skipped
before emitting bind args; missing `.codex`, user-authored `read`/`none`
subpath rules, and existing missing writable-root behavior are
preserved.
- Adds coverage that legacy workspace-write config produces symbolic
project-root metadata carveouts, extra legacy workspace writable roots
still protect existing metadata paths such as `.git`, and bwrap skips
missing `.git`/`.agents` project-root carveouts while preserving missing
`.codex` and user-authored missing subpath rules.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/19772).
* #19776
* #19775
* #19774
* #19773
* __->__ #19772
## Why
The remaining review, interrupt, fuzzy search, feedback, and git-diff
handlers still had local send-error branches that obscured otherwise
simple request handling. This final slice flattens those handlers
without changing the public protocol behavior.
## What Changed
- Streamlined review start, turn interrupt, fuzzy search session,
feedback upload, and git diff handlers in
`codex-rs/app-server/src/codex_message_processor.rs`.
- Converted validation and upload failures into returned JSON-RPC errors
where that avoids nested `send_error`/`return` blocks.
- Left unrelated sandbox setup and notification code untouched.
## Verification
- `cargo check -p codex-app-server`
- `cargo test -p codex-app-server --test all v2::review --
--test-threads=1`
## Summary
- Add the `enable_mcp_apps` feature flag to the `codex-features`
registry
- Keep it under development and disabled by default
## Testing
- Unit tests for `codex-features` passed
- Formatting passed
Michael Bolin