Stack 1 of 3. Follow-ups: #29842 and #29844.
## What changes
Adds a general bounded `fs/walk` operation to the exec server.
The operation returns file and directory entries plus recoverable
per-path errors. It skips symlinks, preserves the existing filesystem
sandbox routing, and enforces depth, directory, entry, and response-size
limits.
This PR only defines and wires the filesystem operation. It does not
change any callers yet.
## Why
The app-server and exec-server expose separate JSON-RPC APIs, but
exec-server currently sources its serialized protocol and envelope types
through app-server-oriented code. Giving each API an explicit owner
makes the crate boundary legible without introducing shared generic
envelopes.
## What changed
- Added `codex-exec-server-protocol` to own exec DTOs, process IDs, and
JSON-RPC envelopes.
- Updated exec-server clients, transports, handlers, and tests to use
the new crate.
- Exposed app-server's existing JSON-RPC types through a public `rpc`
module while retaining root re-exports.
- Preserved existing wire shapes, including exec `PathUri` behavior.
## Stack
This is PR 1 of 6. Next: [PR
#29721](https://github.com/openai/codex/pull/29721), which moves auth
mode below the app wire boundary.
## Validation
- Exec-server protocol and server coverage passed in the focused
protocol test runs.
- App-server protocol schema fixtures passed.
## Why
Downstream refactors are producing confusing code with this
functionality having a very generic name. Encoding the specific
conversion approach in the method name makes it clearer.
## What
Rename `PathUri::from_path` to `PathUri::from_host_native_path` and
update its Rust call sites.
## Why
`ExecutorFileSystem::get_metadata` reports file kind and timestamps but
not size. Internal callers that need to enforce a size limit therefore
have to read the complete file first, which is especially wasteful for
remote filesystems.
This adds the missing internal metadata so consumers can reject
oversized files before transferring or buffering them. The field is
named `size`, matching VS Code's `FileStat.size` filesystem convention.
## What changed
- add `size: u64` to internal `FileMetadata`
- populate it from the underlying filesystem metadata
- carry it through sandbox-helper and remote exec-server responses
- cover files, directories, symlink targets, and sandboxed reads across
local and remote filesystem implementations
The new field is intentionally not exposed through the app-server API.
## Testing
- `just test -p codex-exec-server get_metadata`
- `just test -p codex-exec-server
file_system_sandboxed_metadata_and_read_allow_readable_root`
- `just test -p codex-core-plugins`
- `just test -p codex-skills-extension`
Exec-server filesystem calls should preserve cross-platform `file:` URIs
across the remote boundary instead of converting them through paths
native to the client host.
This changes the exec-server filesystem protocol DTOs to use `PathUri`,
carries those values directly through remote and sandbox-helper
transports, and keeps legacy native absolute-path request strings
readable for compatibility. It also updates protocol documentation and
coverage for URI serialization and non-native URI forwarding.
## Why
We're moving exec-server to use PathUri for its internal path
representations.
## What
Move `ExecutorFileSystem` APIs to use `PathUri` instead of
`AbsolutePathBuf`. Future changes will convert higher-level parts of
exec-server.
## Summary
- add executor filesystem canonicalization as a bound-path operation
- route remote canonicalization through the exec-server filesystem RPC
surface
- keep path normalization attached to the filesystem that owns the path
## Stack
- 2/5 in the skills path authority stack extracted from
https://github.com/openai/codex/pull/25098
- follows merged https://github.com/openai/codex/pull/25121
## Validation
- `cd
/Users/starr/code/codex-worktrees/pr-25098-restack-review-pr1b/codex-rs
&& just fmt`
- Not run: tests/checks (not requested)
- GitHub CI pending on rewritten head
jifandGitHub
Adam Perry @ OpenAIandGitHub
pakrym-oaiandGitHub
starr-openaiandGitHub
