Michael Bolin
828b837235
## Why This is a larger step in the `codex-core` -> `codex-tools` migration called out in `AGENTS.md`. `codex-rs/core/src/tools/spec.rs` had become mostly pure tool-spec assembly plus handler registration. That made it hard to move more of the tool-definition layer into `codex-tools`, because the runtime binding and the crate-independent planning logic were still interleaved in one function. Splitting those concerns gives `codex-tools` ownership of the declarative registry plan while keeping `codex-core` responsible for instantiating concrete handlers. ## What Changed - Add a `codex-tools` registry-plan layer in `codex-rs/tools/src/tool_registry_plan.rs` and `codex-rs/tools/src/tool_registry_plan_types.rs`. - Move feature-gated tool-spec assembly, MCP/dynamic tool conversion, tool-search aliases, and code-mode nested-plan expansion into `codex-tools`. - Keep `codex-rs/core/src/tools/spec.rs` as the core-side adapter that maps each planned handler kind to concrete runtime handler instances. - Update `spec_tests.rs` to import the moved `codex_tools` symbols directly instead of relying on top-level `spec.rs` re-exports. This is intended to be a straight refactor with no behavior change and no new test surface. ## Verification - `cargo test -p codex-tools` - `cargo test -p codex-core tools::spec::tests` --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/openai/codex/pull/16513). * #16521 * __->__ #16513
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 vendored bubblewrap path compiled into
the binary and Codex surfaces a startup warning through its normal notification
path instead of printing directly from the sandbox helper.
Windows
Legacy SandboxPolicy / sandbox_mode configs are still supported on
Windows.
The elevated setup/runner backend supports legacy ReadOnlyAccess::Restricted
for read-only and workspace-write policies. Restricted read access honors
explicit readable roots plus the command cwd, and keeps writable roots
readable when workspace-write is used.
When include_platform_defaults = true, the elevated Windows backend adds
backend-managed system read roots required for basic execution, such as
C:\Windows, C:\Program Files, C:\Program Files (x86), and
C:\ProgramData. When it is false, those extra system roots are omitted.
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 round-trip through the legacy SandboxPolicy model without
changing semantics. Policies that would require direct read restriction,
explicit unreadable carveouts, reopened writable descendants under read-only
carveouts, different writable root sets, or split carveout support in the
elevated setup/runner backend 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.