Files
codex/codex-rs/core
T
Shijie Rao 370b13afc9 Honor client-resolved service tier defaults (#23537)
## Why

Model catalog responses can now advertise a nullable
`default_service_tier` for each model. Codex needs to preserve three
distinct states all the way from config/app-server inputs to inference:

- no explicit service tier, so the client may apply the current model
catalog default when FastMode is enabled
- explicit `default`, meaning the user intentionally wants standard
routing
- explicit catalog tier ids such as `priority`, `flex`, or future tiers

Keeping those states distinct prevents the UI from showing one tier
while core sends another, especially after model switches or app-server
`thread/start` / `turn/start` updates.

## What Changed

- Plumbed `default_service_tier` through model catalog protocol types,
app-server model responses, generated schemas, model cache fixtures, and
provider/model-manager conversions.
- Added the request-only `default` service tier sentinel and normalized
legacy config spelling so `fast` in `config.toml` still materializes as
the runtime/request id `priority`.
- Moved catalog default resolution to the TUI/client side, including
recomputing the effective service tier when model/FastMode-dependent
surfaces change.
- Updated app-server thread lifecycle config construction so
`serviceTier: null` preserves explicit standard-routing intent by
mapping to `default` instead of internal `None`.
- Kept core responsible for validating explicit tiers against the
current model and stripping `default` before `/v1/responses`, without
applying catalog defaults itself.

## Validation

- `CARGO_INCREMENTAL=0 cargo build -p codex-cli`
- `CARGO_INCREMENTAL=0 cargo test -p codex-app-server model_list`
- `cargo test -p codex-tui service_tier`
- `cargo test -p codex-protocol service_tier_for_request`
- `cargo test -p codex-core get_service_tier`
- `RUST_MIN_STACK=8388608 CARGO_INCREMENTAL=0 cargo test -p codex-core
service_tier`
370b13afc9 ยท 2026-05-20 15:57:50 -07:00
History
..

codex-core

This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.

Dependencies

Note that codex-core makes some assumptions about certain helper utilities being available in the environment. Currently, this support matrix is:

macOS

Expects /usr/bin/sandbox-exec to be present.

When using the workspace-write sandbox policy, the Seatbelt profile allows writes under the configured writable roots while keeping .git (directory or pointer file), the resolved gitdir: target, and .codex read-only.

Network access and filesystem read/write roots are controlled by SandboxPolicy. Seatbelt consumes the resolved policy and enforces it.

Seatbelt also keeps the legacy default preferences read access (user-preference-read) needed for cfprefs-backed macOS behavior.

Linux

Expects the binary containing codex-core to run the equivalent of codex sandbox linux (legacy alias: codex debug landlock) when arg0 is codex-linux-sandbox. See the codex-arg0 crate for details.

Legacy SandboxPolicy / sandbox_mode configs are still supported on Linux. They can continue to use the legacy Landlock path when the split filesystem policy is sandbox-equivalent to the legacy model after cwd resolution. Split filesystem policies that need direct FileSystemSandboxPolicy enforcement, such as read-only or denied carveouts under a broader writable root, automatically route through bubblewrap. The legacy Landlock path is used only when the split filesystem policy round-trips through the legacy SandboxPolicy model without changing semantics. That includes overlapping cases like /repo = write, /repo/a = none, /repo/a/b = write, where the more specific writable child must reopen under a denied parent.

The Linux sandbox helper prefers the first bwrap found on PATH outside the current working directory whenever it is available. If bwrap is present but too old to support --argv0, the helper keeps using system bubblewrap and switches to a no---argv0 compatibility path for the inner re-exec. If bwrap is missing, it falls back to the bundled codex-resources/bwrap binary shipped with Codex and Codex surfaces a startup warning through its normal notification path instead of printing directly from the sandbox helper. Codex also surfaces a startup warning when bubblewrap cannot create user namespaces. WSL2 uses the normal Linux bubblewrap path. WSL1 is not supported for bubblewrap sandboxing because it cannot create the required user namespaces, so Codex rejects sandboxed shell commands that would enter the bubblewrap path before invoking bwrap.

Windows

Legacy SandboxPolicy / sandbox_mode configs are still supported on Windows. Legacy read-only and workspace-write policies imply full filesystem read access; exact readable roots are represented by split filesystem policies instead.

The elevated Windows sandbox also supports:

  • legacy ReadOnly and WorkspaceWrite behavior
  • split filesystem policies that need exact readable roots, exact writable roots, or extra read-only carveouts under writable roots
  • backend-managed system read roots required for basic execution, such as C:\Windows, C:\Program Files, C:\Program Files (x86), and C:\ProgramData, when a split filesystem policy requests platform defaults

The unelevated restricted-token backend still supports the legacy full-read Windows model for legacy ReadOnly and WorkspaceWrite behavior. It also supports a narrow split-filesystem subset: full-read split policies whose writable roots still match the legacy WorkspaceWrite root set, but add extra read-only carveouts under those writable roots.

New [permissions] / split filesystem policies remain supported on Windows only when they can be enforced directly by the selected Windows backend or round-trip through the legacy SandboxPolicy model without changing semantics. Policies that would require direct explicit unreadable carveouts (none) or reopened writable descendants under read-only carveouts still fail closed instead of running with weaker enforcement.

All Platforms

Expects the binary containing codex-core to simulate the virtual apply_patch CLI when arg1 is --codex-run-as-apply-patch. See the codex-arg0 crate for details.