## Why
Make it possible to load AGENTS.md from remote exec-servers whose OS is
different than app-server.
## What
- keep `AGENTS.md` discovery and provenance as `PathUri`, with
root-aware parent and ancestor traversal
- expose lifecycle instruction sources as legacy app-server path strings
in events while retaining `PathUri` internally
- preserve and test mixed POSIX and Windows paths in model context and
TUI status output
- cover remote Windows loading end to end by seeding the Wine prefix
through host filesystem APIs
- fix bug in `PathUri`'s parent() implementation that would erase
Windows drive letters
## Summary
- Initialize stderr tracing and the configured OpenTelemetry provider
for local and remote `codex exec-server` startup.
- Instrument the local and remote server entrypoints with a root runtime
span.
- Keep raw Noise environment, registration, and stream identifiers out
of exported spans while preserving them in local debug events.
- Keep telemetry setup in a focused CLI module instead of growing the
top-level command entrypoint.
## Stack
- Previous: none (`#27058` has merged)
- Next: #27466
## Validation
- `just test -p codex-exec-server --lib` (139 passed)
- `just test -p codex-cli --test exec_server` (3 passed)
- `just bazel-lock-check`
- `just fix -p codex-exec-server -p codex-cli`
- `just fmt`
---------
Co-authored-by: Richard Lee <richardlee@openai.com>
## Summary
Remote stdio MCP servers send tool calls by writing JSON-RPC bytes
through `process/write`.
When the exec-server websocket drops at the wrong time, the remote
process can survive session recovery, but the stdin write can still fail
back to RMCP as a transport send error. RMCP then closes the stdio MCP
transport, so tools like `node_repl` are lost even though the
process/session recovery path is working.
This changes `process/write` to be safe to retry across exec-server
recovery:
- adds a required `writeId` to `process/write`
- retries remote `Session::write` with the same `writeId` after
reconnect
- remembers accepted write ids per process so duplicate retries return
`Accepted` without writing the same bytes to child stdin again
- covers both the client retry path and server-side write id dedupe with
tests
In simple terms:
```text
before:
write to MCP stdin -> websocket closes -> write errors -> RMCP closes node_repl
after:
write to MCP stdin -> websocket closes -> reconnect -> retry same writeId
server either writes once or recognizes it already did
```
## Why
Prepare network approval scoping to distinguish execution environments
without changing behavior yet.
## What changed
- Add optional environment IDs to network policy requests.
- Add optional network environment IDs to exec and sandbox request
structs.
- Thread default None values through existing construction points.
- Fix stale constructor call sites that caused the CI compile failures.
## Not included
- Per-environment proxy listeners.
- Network approval cache or prompt behavior changes.
- Ambiguous request attribution handling.
Those behavior changes moved to stacked follow-up #28899.
## Validation
- just fmt
- CI will run tests and clippy
## Summary
- add a provider API that supplies a fresh signed WebSocket URL for each
remote exec-server connection
- refresh the signed URL after disconnects and retry once when a
handshake returns `401 Unauthorized`
- allow `EnvironmentManager` consumers to register remote environments
backed by the URL provider
## Tests
- `just test -p codex-exec-server -E
'test(remote_websocket_client_refreshes_url_after_unauthorized_handshake)
| test(remote_websocket_client_refreshes_url_after_disconnect)'` — 2
passed
- `cargo check -p codex-core-api` — passed
- `just fix -p codex-exec-server` — passed
- `just fix -p codex-core-api` — no test targets; no-op
- `just fmt` — passed
- `just test -p codex-exec-server` — 187 passed; 32 unrelated macOS
sandbox tests could not invoke nested `sandbox-exec` (`Operation not
permitted`)
## Why
Codex can run a remote exec server through the Noise relay, but the
normal
environment-manager path could not establish an
environment-registry-backed
harness connection. Signed rendezvous URLs and harness authorizations
are
short-lived, so reconnects must fetch a fresh bundle instead of
retaining
stale connection credentials. A stalled registry request must also fail
within
the regular remote connection deadline, without exposing these
credentials in
debug logs.
Issue: N/A (internal environment-service integration).
## What Changed
- Add environment-manager configuration for a registry-backed Noise
rendezvous
environment.
- Request a fresh bundle from
`/cloud/environment/{environment_id}/connect` for every physical harness
connection, using the existing 10-second remote connection timeout.
- Share the Environment Registry register, connect, and validate wire
payloads
through `codex-exec-server` and `codex-core-api`.
- Redact the signed rendezvous URL and harness authorization from the
public
connect response's `Debug` output.
- Add focused coverage for registry bundle retrieval, stalled requests,
and
credential redaction.
## Why
Services that proxy the exec-server environment registry endpoints need
to deserialize and forward the same Noise registration and harness-key
validation payloads. Those wire models currently live as private,
serialize-only structs in `exec-server`, which forces consumers to
duplicate the contract.
## What changed
- Add owned serde models for registration and harness-key validation
requests and responses.
- Use those models in the existing exec-server registry client.
- Re-export the models from `codex-exec-server` and `codex-core-api`.
- Keep the harness authorization request free of a derived `Debug`
implementation so it is not accidentally logged.
## Testing
- Focused exec-server registration and harness-key validation tests: 2
passed.
- `cargo check -p codex-core-api`
The full `codex-exec-server` suite compiled and ran 254 tests: 222
passed, while 32 existing filesystem sandbox tests could not run under
the nested macOS sandbox (`sandbox_apply: Operation not permitted`).
Co-authored-by: Codex <noreply@openai.com>
## Why
It should be possible for app-server to handle "foreign" OS paths in
unified_exec working directories, allowing e.g. a Linux app-server to
run processes on e.g. a Windows exec-server.
## What
Convert the core unified_exec cwd values to use `PathUri`.
Adds fallible path conversion in several places to try to minimize the
scope of this change. The only time this change suppresses errors from
converting `PathUri` to an `AbsolutePathBuf` is when the turn is
configured with no sandboxing at all to allow us to make progress
testing without sandboxing.
Future changes to apply_patch and sandboxing will clean up these error
paths.
A tool's cwd is resolved from joining a model-provided workdir to the
environment's cwd. When using `AbsolutePathBuf::join()`, an
absolute-path workdir would overwrite the environment's cwd and we would
resolve permissions/sandboxing against the model-provided path. This
change extends `PathUri::join()` to also treat an absolute rhs as an
override of the base/lhs.
This also removes some coverage from the remove_env_windows tests until
a follow-up converts foreign paths in command exec events correctly.
## Breaking Changes
When using `AbsolutePathBuf::join()` for workdir resolution, we ended up
resolving tilde-prefixed paths against the app-server's `$HOME`, e.g.
`~/foo/bar` becomes `/home/anp/foo/bar`. It's difficult to do this with
`PathUri` joining, so after offline discussion this PR no longer
implements it.
A quick check of some power users' rollouts suggests that models don't
actually generate home-prefixed absolute working directories for their
spawns, so this shouldn't have any real blast radius.
## Why
This is the final PR in the Windows fs-helper sandbox stack and contains
the actual bug fix.
The exec-server filesystem helper is a direct-spawn path: it asks
`SandboxManager` for a `SandboxExecRequest`, then launches the returned
argv itself. That works on macOS and Linux because the transformed argv
is already a self-contained sandbox wrapper. On Windows, the transformed
request carried `WindowsRestrictedToken` metadata, but the direct-spawn
fs-helper runner still launched the helper argv directly.
That means Windows filesystem built-ins backed by the fs-helper could
run with the parent Codex process permissions instead of the configured
Windows sandbox. This PR makes the direct-spawn transform produce a
self-contained Windows wrapper argv before fs-helper launches it.
## What Changed
- Added `SandboxManager::transform_for_direct_spawn()` for callers that
launch the returned argv themselves.
- Wrapped Windows restricted-token direct-spawn requests with `codex.exe
--run-as-windows-sandbox` and then marked the outer request as
unsandboxed, matching the macOS/Linux wrapper argv shape.
- Updated `exec-server/src/fs_sandbox.rs` to use the direct-spawn
transform for fs-helper launches.
- Materialized the inner `codex.exe --codex-run-as-fs-helper` executable
into `.sandbox-bin` so the sandboxed user can run it.
- Carried runtime workspace roots through `FileSystemSandboxContext` as
`PathUri` values so `:workspace_roots` policies resolve correctly
without sending native client paths over exec-server JSON.
- Preserved wrapper setup identity environment needed by Windows sandbox
setup without changing the serialized inner helper environment.
## Verification
- `just bazel-lock-update`
- `just bazel-lock-check`
- `just test -p codex-sandboxing transform_for_direct_spawn_windows`
- `just test -p codex-exec-server fs_sandbox::tests`
- `just fix -p codex-windows-sandbox -p codex-sandboxing -p
codex-exec-server -p codex-core -p codex-file-system`
Local note: `just fmt` completed Rust formatting, but this workstation
still fails the non-Rust formatter phases because uv cannot open its
cache and the local buildifier/dotslash path is missing.
## Why
PR #28512 retries a failed session recovery every 100 ms. Every Noise
recovery attempt first asks the environment registry for a fresh
connection bundle, even when the eventual failure comes from the
WebSocket or initialize handshake. During an outage, that could make
each disconnected client call the registry about 250 times during the
25-second recovery window.
## What changes
All retryable Noise recovery failures now use a separate backoff
schedule:
```text
base: 500 ms -> 1 s -> 2 s -> 4 s -> 5 s maximum
actual: 500-750 ms, 1-1.5 s, 2-3 s, 4-6 s, 5-7.5 s
```
The extra 0-50% is deterministic per-session jitter so disconnected
clients do not retry together. Direct WebSocket recovery keeps the
existing 100 ms retry because it does not re-enter the registry.
Supersedes #28288 (closed).
## Why
A short WebSocket interruption currently ends every client-side process
handle, even though exec-server keeps the server session and its
processes alive for a short time.
This is especially visible for executor-backed stdio MCP servers: a
temporary connection loss becomes a permanent `Transport closed` error.
The server already has the information needed to resume the session, but
the client opens a fresh session instead of using it.
This change reconnects below the process and MCP layers. Existing
process handles stay valid, missed output is recovered, and the same
server-side processes continue running.
## State machine
One logical `ExecServerClient` stays alive while its underlying RPC
connection changes generations.
```text
transport closes
+------------------------------------------------+
| v
+-------------+ +-------------+
| Connected | | Recovering |
+-------------+ +-------------+
^ |
| session resumed, processes caught up | retryable error
+------------------------------------------------+ loops until deadline
|
| deadline or permanent error
v
+-------------+
| Failed |
+-------------+
```
### `Connected`
- New RPC calls use the current connection.
- Process notifications are published in sequence order.
- A disconnect only starts recovery if it came from the current
connection generation. Late events from older generations cannot replace
the active connection.
### `Recovering`
- New calls wait instead of choosing a half-connected RPC client.
- Existing process handles, wake subscriptions, and event subscriptions
stay open.
- Streaming HTTP response bodies fail immediately because their byte
streams cannot be resumed safely.
- Recovery first waits for process starts that were already in flight. A
start whose result became ambiguous is cleaned up after reconnection
instead of being silently adopted.
- The client reconnects with the learned `session_id`. The server may
briefly report that the old connection is still attached, so that error
is retried until the detach finishes.
- The notification consumer starts before the resume handshake
completes. This prevents a busy process from filling the notification
queue and blocking the initialize response.
- Before installing the new connection, the client catches up every
recoverable process with `process/read`.
### `Failed`
- Recovery stops after 25 seconds or after a permanent error.
- Waiting calls are released with one stable disconnect error.
- Existing process sessions receive a terminal failure instead of
waiting forever.
## Recovering process events
Output, exit, and close events share one sequence. During normal
operation, the client buffers early events until every lower sequence
has been published.
After reconnection, the client reads each process starting after its
last published sequence:
1. Retained output chunks are inserted by sequence number.
2. Exit and close state are reconstructed in their sequence positions.
3. Events already received as live notifications are ignored as
duplicates.
4. Newly contiguous events are published in order.
5. If the server no longer retains enough output to fill a sequence gap,
only that process is terminated and failed. The recovered connection
remains usable for other processes.
The server reports its full next event sequence for unbounded reads,
including exit and close events. Closed processes remain readable for
the same 30-second window used to retain detached sessions.
## Other details
- Detached server sessions are retained for 30 seconds, leaving margin
around the client's 25-second recovery deadline.
- Session attach and detach update the active notification sender under
the same attachment lock, so an old connection cannot clear a newly
attached sender.
- A dedicated error code distinguishes the temporary "session is still
attached" race from permanent initialization errors.
- Process starts are identity-checked on both client and server. Cleanup
from an older start cannot remove a newer process that reused the same
ID.
- Mutating requests that were already in flight when the transport
closed are not replayed, because the client cannot know whether the
server applied them. Requests started after recovery is known wait for
the replacement connection.
- We assume the server/client version stays in sync (on the before/after
this PR)
## User impact
Long-running commands and stdio MCP servers can survive a temporary
exec-server WebSocket interruption without changing process IDs or
losing output produced during the outage.
## Why
`fs/readFile` buffers the entire file in one response, which makes large
remote reads expensive and prevents callers from applying backpressure.
We need an opt-in streaming path with bounded block sizes while
preserving the existing single-call API for small and sandboxed reads.
## What changed
- Add `ExecServerClient::stream`, returning a named `FileReadStream`
that implements `futures::Stream` and yields immutable 1 MiB byte
blocks.
- Add internal `fs/open`, `fs/readBlock`, and `fs/close` RPCs.
`fs/readBlock` accepts an explicit offset and length.
- Keep unsandboxed files open between block reads, cap open handles per
connection, and clean them up on EOF, error, stream drop, explicit
close, or connection shutdown.
- Reject platform-sandboxed streaming opens instead of turning the
one-shot sandbox helper into a persistent server. Existing `fs/readFile`
behavior is unchanged.
## Testing
- `just test -p codex-exec-server`
- Integration coverage for 1 MiB chunking, exact block-boundary EOF,
sandbox rejection, and continued reads from the opened file after path
replacement.
- Handle-manager coverage for non-sequential offsets, variable block
lengths, the 128-handle limit, and capacity release after close.
## Why
Ensure a consistent string format when exposing path conversion errors
to the model.
## What
- Render `PathUriParseError::InvalidFileUriPath` as `'$PATH' is invalid
on '$OS'`.
The workspace denies `clippy::expect_used` in production. Although
`clippy.toml` allows `expect` in tests, Bazel Clippy compiles
integration-test helper code in a way that does not receive that
exemption, which encouraged verbose `unwrap_or_else(... panic!(...))`
and equivalent `match`/`let else` forms.
This allows `clippy::expect_used` once at each integration-test crate
root (including aggregated suites and test-support libraries), then
replaces manual panic-based Result and Option unwraps with
`expect`/`expect_err`. Standalone `tests/*.rs` files remain their own
crate roots. Intentional assertion and unexpected-variant panics remain
unchanged, and the production `expect_used = "deny"` lint remains in
place.
The cleanup is mechanical and net-negative in line count.
## Why
The transport in
[openai/codex#26242](https://github.com/openai/codex/pull/26242) needs
to be used by every remote orchestrator-to-executor connection before
JSON-RPC traffic starts.
## Changes
- Generates one executor Noise identity when remote exec-server starts
and registers its public key.
- Creates a harness identity for each physical remote environment
connection.
- Fetches a fresh registry bundle before connecting and validates the
authenticated harness key before completing the executor handshake.
- Multiplexes encrypted logical streams over the existing executor
WebSocket.
- Adds bounded stream, handshake-failure, and reassembly state.
- Adds safe lifecycle diagnostics without logging keys, authorizations,
plaintext, or ciphertext.
- Covers reconnects, replay rejection, validation failure, framing
limits, and encrypted JSON-RPC tool traffic.
## Stack
1. [openai/codex#26242](https://github.com/openai/codex/pull/26242):
Noise channel and relay transport
2. **[openai/codex#26245](https://github.com/openai/codex/pull/26245)**:
remote registration and runtime activation
## Verification
- `just test -p codex-exec-server`
- `just fix -p codex-exec-server`
- `just bazel-lock-check`
- `cargo shear`
---------
Co-authored-by: Codex <noreply@openai.com>
## Why
We want to exercise a linux app-server against a windows exec-server
without having to repeat every test case. This approach has slight
precedent in the remote docker test setup.
## What
Run the shared `codex-core` integration suite against Windows
exec-server behavior from Linux. This makes cross-OS path and shell
regressions visible while keeping unsupported cases owned by individual
tests.
- Add `local`, `docker`, and `wine-exec` test environment selection with
legacy Docker compatibility.
- Extend `codex_rust_crate` to generate a sharded Wine-exec variant
using a cross-built Windows server and pinned Bazel Wine/PowerShell
runtimes.
- Teach remote-aware helpers about Windows paths and track temporary
incompatibilities with source-local `skip_if_wine_exec!` calls and
follow-up reasons.
## Why
Progress towards letting app-server and exec-server run on different
platforms, specifically for sandbox configuration.
## What
- Make the filesystem path containment hierarchy generic, defaulting to
`AbsolutePathBuf` for now.
- Have clients specify `AbsolutePathBuf` or `PathUri` directly where
needed.
- Use `PathUri` throughout exec-server filesystem protocol and trait
boundaries.
- Implement `From` for conversion to path URIs and `TryFrom` for
fallible conversion to absolute paths through the generic type
hierarchy.
## Why
Rendezvous forwards traffic between the orchestrator and exec-server.
The endpoints need to authenticate each other and encrypt that traffic
without trusting Rendezvous with plaintext or endpoint keys.
## Changes
- Adds a hybrid Noise IK channel through Clatter using X25519,
ML-KEM-768, AES-256-GCM, and SHA-256.
- Binds each handshake to `environment_id`, `executor_registration_id`,
and `stream_id`.
- Pins the registry-provided executor key and carries the harness
authorization inside the encrypted handshake.
- Orders relay frames before consuming Noise nonces and fragments large
JSON-RPC messages into bounded records.
- Bounds handshake payloads, frames, streams, and message reassembly.
Runtime activation is in
[openai/codex#26245](https://github.com/openai/codex/pull/26245).
## Stack
1. **[openai/codex#26242](https://github.com/openai/codex/pull/26242)**:
Noise channel and relay transport
2. [openai/codex#26245](https://github.com/openai/codex/pull/26245):
remote registration and runtime activation
## Verification
- `just test -p codex-exec-server`
- Oversized initiator payload regression coverage
- `just fix -p codex-exec-server`
- `just bazel-lock-check`
- `cargo shear`
---------
Co-authored-by: Codex <noreply@openai.com>
## Why
The ws pump refactor removed the relay keepalive timers that had been
added to keep idle rendezvous connections alive. An idle relay could
therefore be closed by the rendezvous service or a load balancer,
disconnecting executor-backed MCP processes.
## What
- restore periodic WebSocket ping frames on both rendezvous relay
endpoints
- keep missed-tick behavior bounded with `MissedTickBehavior::Skip`
- cover the harness and remote-environment pumps with focused
traffic-after-keepalive tests
## Why
Next slice needed to make progress on the `remote_env_windows` test is
to support passing a Windows cwd for the remote environment and using
that environment's native shell. This lets the test run a real Windows
process instead of only recording an early path or shell mismatch.
## What
- change `TurnEnvironmentSelection.cwd` from `AbsolutePathBuf` to
`PathUri`
- convert local cwd values to URIs when constructing selections
- preserve a remote primary cwd instead of replacing it with the local
legacy fallback
- prefer the selected environment's discovered shell for unified exec,
falling back to the session shell when unavailable
- convert back to a host-native absolute path at current native-only
consumer boundaries
- reject or deny unsupported foreign cwd values at the existing
request-permissions boundary, with TODOs for its future migration
- extend the hermetic Wine test to execute Windows PowerShell in
`C:\windows` and verify successful process completion
- record the current app-server rejection against the same Wine-backed
remote Windows fixture when its cwd is supplied as a native Windows path
## Intent
Keep Bazel and Starlark files consistently formatted without requiring
contributors to install or version buildifier themselves.
## Implementation
- Add a SHA-256-pinned, cross-platform DotSlash manifest for buildifier
v8.5.1.
- Run buildifier from the shared `just fmt` and `just fmt-check` driver,
with Windows-safe explicit DotSlash invocation.
- Provision DotSlash in formatting CI and contributor devcontainers, and
document the source-build prerequisite.
- Apply the initial mechanical buildifier formatting baseline.
## Why
This is the second-to-last place in the exec-server protocol that needs
to migrate to URIs to support cross-OS operation.
## What
- Change `ExecParams.cwd` to `PathUri`.
- Keep the cwd URI-shaped through core and rmcp producers, converting it
to `AbsolutePathBuf` only in `LocalProcess::start_process`.
- Reject non-native cwd URIs before launch and update the affected
protocol documentation and call sites.
## Why
We want to make it possible for an app-server orchestrator on one OS to
control an exec-server on another host running a different OS. In
practice this kinda already works if you get lucky and the two hosts
have the same path format, but we mangle quite a lot of operations if
either end is Windows.
This test starts exercising that interaction, although right now the
initial bootstrap fails. Future changes will expand the test's
assertions to match improved support.
## What
Stacked on #27964. This adds a small Windows exec-server fixture and a
Linux protocol smoke test using the reusable Wine harness, covering
Windows environment discovery, non-TTY `cmd.exe` execution, output, exit
status, and working directory.
Once we've got the full codex binary cross-building under Bazel we could
consider moving to the real binary instead of the stripped down
exec-server-only binary used here.
## Why
`PathUri::from_abs_path` can fail for absolute paths that do not have a
normal `file:` URI representation, forcing filesystem call sites to
handle a conversion error even though the original path can be preserved
losslessly.
## What
Make `from_abs_path` infallible and migrate its callers. Unrepresentable
paths use `file:///%00/bad/path/<base64>`, encoding Unix bytes or
Windows UTF-16LE; `to_abs_path` validates and decodes that fallback. The
leading encoded null reserves a namespace that cannot collide with a
real Unix or Windows path, and fallback URIs remain opaque to lexical
path operations.
## Validation
Added path-URI coverage for Unix null and non-UTF-8 paths, Windows
device/verbatim and non-Unicode paths, serialization, malformed
fallbacks, opaque lexical operations, invalid native payloads, and
literal `/bad/path` collision resistance.
## 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`
## Why
Sandbox cwd values can cross app-server and exec-server host boundaries.
They should retain URI semantics until the receiving host validates them
instead of being interpreted early as native paths.
## What
- Carry `PathUri` through filesystem sandbox contexts, sandbox commands,
and transform inputs.
- Convert command and policy cwd once in `SandboxManager::transform`,
then keep launch requests native.
- Preserve sandbox cwd over remote filesystem transport and reject
non-native URIs without fallback.
- Cache paired native/URI turn-environment cwd values during migration,
with immutable access to keep them synchronized.
- Extend existing protocol, forwarding, transform, and core runtime
tests.
## Why
First-party async traits should expose their `Send` contracts explicitly
without requiring `async_trait`. This completes the migration pattern
established in #27303 and #27304.
## What changed
- Replaced the remaining first-party `async_trait` traits with native
return-position `impl Future + Send` where statically dispatched and
explicit boxed `Send` futures where object safety is required.
- Kept implementations behavior-preserving, outlining existing async
bodies into inherent methods where that keeps the diff reviewable.
- Removed all direct first-party `async-trait` dependencies and the
workspace dependency declaration.
- Added a cargo-deny policy that permits `async-trait` only through the
remaining transitive wrapper crates.
- Updated `rand` from 0.8.5 to 0.8.6 to resolve RUSTSEC-2026-0097 and
keep the full cargo-deny check passing.
## Validation
- `just test -p codex-exec-server`: 216 passed, 2 skipped.
- `just test -p codex-model-provider`: 39 passed.
- `just test -p codex-core` and `just test`: changed tests passed;
remaining failures are environment-sensitive suites unrelated to this
migration.
- `cargo deny check`
- `just fix`
- `just fmt`
- `cargo shear`
- `just bazel-lock-check`
## Summary
Path composition is already handled by `PathUri`, leaving `fs/join` and
`fs/parent` as redundant exec-server protocol surface. Because
app-server and exec-server are deployed atomically, these obsolete
methods can be removed without a compatibility shim.
This removes the protocol constants and payloads, public client APIs,
server registrations and handlers, and endpoint-only tests. Existing
in-process `PathUri` join/parent coverage remains.
## Validation
- `just test -p codex-exec-server` (215 passed, 2 skipped)
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.
We're switching to using a static encoding of the host path in
`PathUri`. We may need a type like this again but we can add it when
it's more compelling.
Stacked on #27454.
## Why
The exec-server's existing filesystem tests only run on `#[cfg(unix)]`.
We should be running the applicable ones on Windows, and also include
the basic filesystem operations that will be modified by migrating to
`PathUri`.
## What
Split platform-neutral local/remote tests into a shared Unix/Windows
suite while keeping the existing `AbsolutePathBuf` API, and add Windows
junction canonicalization coverage.
## Why
A long-running unified exec process started with `tty: false` could not
be interrupted via `write_stdin`: ordinary non-TTY stdin writes are
rejected once stdin is closed, but an exact U+0003 payload should still
map to a process interrupt. The interrupt should flow through the same
process lifecycle path as a real signal so Codex preserves
process-reported output and exit metadata instead of fabricating a
Ctrl-C exit code or tearing down the session early.
## What Changed
- Add `process/signal` to exec-server with `ProcessSignal::Interrupt`
and an empty response.
- Add a non-consuming `ProcessHandle::signal` path for spawned
processes; on Unix it sends SIGINT to the process group and leaves
terminate/hard-kill unchanged.
- Route non-TTY U+0003 `write_stdin` through `process.signal(...)`
instead of `terminate`, then let the normal post-write collection path
drain output and observe exit.
- Add exec-server coverage where a shell `trap INT` handler prints the
signal and exits with its own code.
- Add unified exec coverage where a `tty: false` process traps SIGINT,
emits output, and exits with its own code.
## Validation
- `just test -p codex-exec-server
exec_process_signal_interrupts_process`
- `just test -p codex-exec-server`
- `just test -p codex-core
write_stdin_ctrl_c_interrupts_non_tty_session`
## Why
Shell detection needs to be available through the `Environment`
abstraction so callers can ask the selected local or remote environment
for shell metadata without adding a separate HTTP endpoint or parallel
info-source path. This keeps shell metadata shaped like the existing
environment-owned filesystem capability and lets remote environments
answer through exec-server JSON-RPC.
## What changed
- Added `environment/info` to the exec-server protocol/client/server and
exposed `Environment::info()`.
- Added local and remote environment info providers on `Environment`,
following the existing capability-provider pattern used for filesystem
access.
- Moved the shared shell detection logic into `codex-shell-command` and
kept core shell APIs as wrappers around that implementation.
- Returned shell metadata as `EnvironmentInfo { shell: ShellInfo }`
using the existing shell detection path.
- Added a remote environment test that calls `Environment::info()`
through an exec-server-backed environment.
## Validation
- `git diff --check`
- `just test -p codex-shell-command`
- `just test -p codex-core -E 'test(/shell::tests::/)'`\n- `just test -p
codex-exec-server environment`
## 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
## Summary
- add public `codex_exec_server::EnvironmentPathRef`
- bind an absolute path to its owning executor filesystem
- keep path operations in the next review slice
## Stack
- 1/5 in the skills path authority stack extracted from
https://github.com/openai/codex/pull/25098
## Validation
- `cd /Users/starr/code/codex-worktrees/pr-25098-restack4/codex-rs &&
just fmt`
- GitHub CI pending on rewritten head
## Summary
- preserve macOS `__CF_USER_TEXT_ENCODING` when launching the sandboxed
fs helper
- keep the fs-helper env narrow; this adds only the CoreFoundation
startup var instead of copying the broader MCP stdio baseline
- add focused coverage that the helper keeps that var without admitting
`HOME`
## Diagnosis
The sandboxed fs helper is not launched like a normal child process.
Exec-server rebuilds its environment from an allowlist, then calls
`env_clear()` before re-execing Codex with `--codex-run-as-fs-helper`.
That helper dispatches before the normal Codex startup path and only
needs to boot a small Tokio runtime, read one JSON request from stdin,
perform the direct filesystem operation, and write one JSON response.
The reported macOS hang sampled the helper before Rust main, in
CoreFoundation initialization while resolving the default text encoding:
`_CFStringGetUserDefaultEncoding -> getpwuid_r -> notify_register_check
-> bootstrap_look_up3 -> mach_msg2_trap`. The fs-helper allowlist kept
`PATH` and temp vars for runtime needs, but it dropped macOS
`__CF_USER_TEXT_ENCODING`. Other Codex subprocess launchers that
intentionally build a minimal Unix baseline, such as MCP stdio, already
preserve that variable.
My read is that stripping `__CF_USER_TEXT_ENCODING` forced this internal
helper down CoreFoundation's fallback user-lookup path, and that lookup
intermittently wedged on the affected machine before the helper could
read stdin or touch the target file. Preserving only this macOS startup
variable avoids that fallback without broadening the fs-helper
environment to shell-like vars such as `HOME`, `USER`, locale settings,
terminal settings, or proxy credentials.
Internal Slack thread omitted from the public PR body.
## Validation
- `cd codex-rs && just fmt`
- `git diff --check`
## Summary
- terminate sandbox filesystem helpers when the Tokio child handle is
dropped
## Why
A sandbox filesystem helper can stall during process startup before
reading stdin. If the owning async operation is cancelled or torn down,
the spawned helper should not remain running as an orphaned process.
Setting `kill_on_drop(true)` gives the filesystem helper the cleanup
behavior that Tokio child processes otherwise do not enable by default.
This intentionally does not add a timeout. It does not detect or recover
an active hung file edit while the owning future remains alive. A more
precise startup-health mechanism can be handled separately.
## Validation
- `just test -p codex-exec-server` (186 tests passed; benchmark smoke
passed)
- `just fmt`
- `just fix -p codex-exec-server`
- `git diff --check`
Adds failure-only logging for MCP streamable HTTP post_message calls and
the underlying reqwest send path, capturing the MCP method/request id,
endpoint shape, auth-header presence, timeout/connect classification,
and sanitized error source chain without logging headers, bodies,
tokens, or full URLs.
## Why
`codex exec-server` has a local WebSocket listener, but it did not apply
the same browser-origin request handling as the `app-server` WebSocket
transport. Requests that carry an `Origin` header should not be upgraded
by this local transport, keeping both local WebSocket servers consistent
and avoiding unexpected browser-initiated connections.
## What changed
- Added an Axum middleware guard in
`codex-rs/exec-server/src/server/transport.rs` that returns `403
Forbidden` for requests carrying an `Origin` header.
- Added an integration test in `codex-rs/exec-server/tests/websocket.rs`
that covers rejection of an `Origin`-bearing WebSocket handshake.
- Kept ordinary WebSocket clients unchanged: existing no-`Origin`
initialization and process behavior remains covered by the crate tests.
## Validation
- `just test -p codex-exec-server` test phase (`186 passed`; run outside
the parent macOS sandbox so nested sandbox tests can execute)
- `just clippy -p codex-exec-server`
## Overview
Allow remote `codex exec-server` registration to use existing API-key
auth while restricting where those credentials can be sent.
- Accept `CodexAuth::ApiKey` for the normal `--remote` registration
path.
- Restrict API-key remote registration to HTTPS `openai.com` and
`openai.org` hosts and subdomains, with explicit HTTP loopback support
for local development.
- Disable registry registration redirects so credentials cannot be
forwarded to an unvalidated destination.
- Retain `--use-agent-identity-auth` as the explicit Agent Identity
path.
- Document remote registration using `CODEX_API_KEY`.
## Big picture
Callers can now provide an API key directly to `exec-server`
registration without first establishing ChatGPT login state:
```sh
CODEX_API_KEY="$OPENAI_API_KEY" \
codex exec-server \
--remote "https://<host>.openai.org/api" \
--environment-id "$ENVIRONMENT_ID"
```
## Validation
- `cargo fmt --all` (`just fmt` is not installed on this host)
- `cargo test -p codex-cli -p codex-exec-server`
## Summary
- Bump the workspace Rust toolchain from `1.93.0` to `1.95.0` across
Cargo, Bazel, CI, release workflows, devcontainers, and the Codex
environment config.
- Refresh `MODULE.bazel.lock` so the Bazel Rust toolchain artifacts
match the new version.
- Leave purpose-specific toolchains unchanged, including the
`argument-comment-lint` nightly and the upstream `rusty_v8` `1.91.0`
build pin.
- Includes fixes for new lints from `just fix` and a few codex-authored
fixes for lints without a suggestion.
## Summary
- replace the one-shot lazy remote exec-server cache with a
lock-protected current client
- when the cached websocket client is already disconnected, create one
fresh websocket client/session on the next `get()`
- keep existing disconnect failure behavior for old process sessions and
HTTP body streams; do not add session resume or request retry
## Why
The prior PR direction was trying to grow into session restore: resume
the old `session_id`, preserve existing process handles, and add
reconnect retry policy. That is more machinery than we want for this
slice.
For now, the useful minimum is simpler: later fresh remote operations
should not be stuck behind a dead cached websocket client, but anything
already attached to the dead connection should fail loudly through the
existing disconnect path. The server already has detached-session
cleanup via its existing TTL, so this PR does not need to add
client-side session preservation.
## What Changed
- `LazyRemoteExecServerClient::get()` now keeps the current concrete
client in a small mutex-protected cache plus one async connect lock.
- If that cached client is still connected, `get()` returns it.
- If that cached websocket client has observed the transport close,
`get()` creates a brand-new websocket client with a brand-new
exec-server session and replaces the cache.
- If that cached client is stdio-backed, behavior stays one-shot: the
dead client is returned and later work surfaces the existing disconnect
error.
- No `resume_session_id`, backoff, request replay, or existing
`RemoteExecProcess` rebinding is added here.
- Added focused websocket coverage that proves two concurrent `get()`
calls after disconnect share one fresh replacement client/session.
## Summary
- migrate exec-server remote registration naming from executor to
environment
- align CLI, public Rust exports, registry error messages, and relay
test fixtures with the environment registry contract
- keep the live registration path and response model consistent with
`/cloud/environment/{environment_id}/register`
## Verification
- `cargo test -p codex-exec-server
remote::tests::register_environment_posts_with_auth_provider_headers
--manifest-path /Users/richardlee/code/codex/codex-rs/Cargo.toml`
- `cargo test -p codex-exec-server --test relay
multiplexed_remote_environment_routes_independent_virtual_streams
--manifest-path /Users/richardlee/code/codex/codex-rs/Cargo.toml`
- `cargo check -p codex-cli --manifest-path
/Users/richardlee/code/codex/codex-rs/Cargo.toml` (still running when PR
opened; will update after completion if needed)
## Why
Exec-server websocket handling had separate reader and writer tasks for
the same socket. That made websocket control-frame handling asymmetric:
the task reading frames could observe `Ping`, but the task allowed to
write frames was elsewhere. This PR moves each physical websocket onto
one always-running pump so the socket owner can handle application
frames and websocket control frames together.
## What changed
- Refactored direct exec-server websocket connections in `connection.rs`
to use one task that owns the websocket for outbound JSON-RPC, inbound
JSON-RPC, periodic keepalive pings, and `Ping` -> `Pong` replies.
- Refactored relay websocket handling in `relay.rs` the same way for
both the harness-side logical connection and the multiplexed executor
physical socket.
- Preserved the existing keepalive ownership policy: outbound direct
websocket clients still send periodic pings, inbound Axum accepts only
reply with pongs, and relay physical websocket endpoints keep their
existing periodic pings.
- Added focused websocket pump tests for ping/pong, binary JSON-RPC,
relay data, malformed relay text frames, and close/disconnect behavior.
- Reconnect behavior is intentionally left for a follow-up.
## Validation
- Devbox Bazel focused unit target:
- `//codex-rs/exec-server:exec-server-unit-tests
--test_filter='websocket_connection_|harness_connection_|multiplexed_executor_'`
This updates remote `exec-server` registration to use normal Codex auth
instead of a registry-issued credential. The registry request is built
from the existing auth-provider path, which preserves the biscuit-only
registry contract introduced in
[openai/openai#924101](https://github.com/openai/openai/pull/924101)
while removing the old remote registry bearer env var and its direct
transport assumptions.
The default remote flow uses persisted ChatGPT auth from the normal
Codex config/storage path. This PR also includes the containerized Agent
Identity path needed by
[openai/openai#924260](https://github.com/openai/openai/pull/924260):
remote `exec-server` accepts `--allow-agent-identity-auth`, permits
Agent Identity auth loaded from `CODEX_ACCESS_TOKEN` only when that flag
is present, and reuses the existing Agent task registration plus derived
`AgentAssertion` header generation. API-key auth remains unsupported,
and Agent Identity stays opt-in.
Validation performed beyond normal presubmit coverage:
- `cargo fmt --all --check`
- `cargo check -p codex-cli`
- `cargo test -p codex-exec-server`
- `cargo test -p codex-cli exec_server_agent_identity_auth_flag_`
- `cargo test -p codex-cli remote_exec_server_auth_mode_`
I also attempted `cargo test -p codex-cli`. The new CLI tests passed
inside that run, but the suite ended on an unrelated local
marketplace-state failure in
`plugin_list_excludes_unconfigured_repo_local_marketplaces`.
## Why
The Docker remote-env coverage was failing before it reached the
behavior those tests are meant to exercise. The remote-aware test
fixture only registered the remote environment, so tests that
intentionally select both `local` and `remote` could not start a turn.
After that was fixed, two tests exposed stale fixtures: the approval
test was auto-approving under workspace-write, and the remote
`view_image` test was writing invalid PNG bytes.
## What Changed
- Added `EnvironmentManager::create_for_tests_with_local(...)` so tests
can keep the provider default while also selecting `local` explicitly.
- Updated `build_remote_aware()` to use that test-only manager when a
remote exec-server URL is present.
- Changed the remote apply-patch approval helper to use
`SandboxPolicy::new_read_only_policy()` so the test actually exercises
approval caching per environment.
- Replaced the hardcoded remote `view_image` PNG blob with the existing
`png_bytes(...)` helper so the test uses a valid image fixture.
## Validation
Ran these isolated Docker remote-env tests on the devbox with
`$remote-tests` setup:
-
`suite::remote_env::apply_patch_freeform_routes_to_selected_remote_environment`
-
`suite::remote_env::apply_patch_approvals_are_remembered_per_environment`
-
`suite::remote_env::apply_patch_intercepted_exec_command_routes_to_selected_remote_environment`
-
`suite::remote_env::exec_command_routes_to_selected_remote_environment`
- `suite::view_image::view_image_routes_to_selected_remote_environment`
All five pass.
## Why
Remote exec-server now needs one executor websocket to serve multiple
harness JSON-RPC sessions. Rendezvous routes by `stream_id`, and the
exec-server side needs to use the same stable relay frame contract
instead of a hand-rolled JSON shape.
The relay protocol also needs to make ownership boundaries clear:
harness and executor endpoints own sequencing, acks, retries, duplicate
suppression, segmentation, and reassembly; rendezvous only routes
frames.
## What Changed
- Add the checked-in `codex.exec_server.relay.v1.RelayMessageFrame`
proto plus generated prost bindings for `codex-exec-server`.
- Encode remote harness/executor relay traffic as binary protobuf
websocket frames while keeping local websocket JSON-RPC unchanged.
- Demux executor-side relay streams into independent
`ConnectionProcessor` sessions keyed by `stream_id`.
- Add a programmatic `RemoteExecutorConfig::with_bearer_token(...)`
constructor for non-CLI callers and integration tests.
- Add an integration test that starts the remote executor against a fake
registry/rendezvous websocket and verifies two virtual streams share one
executor websocket without cross-talk, including per-stream reset
behavior.
- Document the remote relay envelope, sequence ranges, `ack`/`ack_bits`,
and endpoint responsibilities in `exec-server/README.md`.
## Verification
- `cargo test -p codex-exec-server --test relay
multiplexed_remote_executor_routes_independent_virtual_streams --
--exact`
- `cargo test -p codex-exec-server --test relay`
- `cargo test -p codex-exec-server` passed outside the sandbox. The
sandboxed run hit macOS `sandbox-exec: sandbox_apply: Operation not
permitted` in filesystem sandbox tests.
Adam Perry @ OpenAIandGitHub
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Anton PanasenkoandGitHub
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