## What changed
- Add the `shellSnapshotV2` executor capability and an optional shell snapshot request to `ExecParams`.
- Capture and restore Unix shell state and profile exports from an in-memory, attachment-scoped cache for `bash`, `zsh`, and `sh`.
- Apply environment policies, runtime `PATH` entries, sandbox context, and live managed-proxy settings when preparing restored commands.
- Bound snapshot size, capture time, scope length, and cache capacity, and fall back to the original command when capture fails.
## Testing
- Cover local, remote, TTY, sandboxed, and supported-shell execution, plus environment filtering, proxy handling, in-memory reuse, and capture failure fallback.
GitOrigin-RevId: 624f747972c249c88c6f10f42cf0af97b75b5541
## Why
A local stdio MCP server can exit while its descendants remain alive. Cleaning up
only the server process can therefore leak processes after client shutdown.
## What changed
- Contain locally launched MCP servers in non-breakaway Windows job objects and
terminate the job during shutdown so descendants exit with the server.
- Preserve compatibility when job creation or assignment is unavailable by
retrying without containment and terminating an owned process handle instead.
- Use the process-group member fallback when terminating piped processes on
macOS.
## Testing
- Cover descendant cleanup and breakaway prevention for both local MCP protocol
modes on Windows.
- Cover the Windows nested-job assignment fallback and verify the suspended
process resumes before handle-based termination.
GitOrigin-RevId: 33d3cc122de8f7ce0ae69a649b12ea0ff64b7c6f
## Why
Signaling an MCP server's process group can fail with `EPERM` on macOS,
preventing owned descendants from being terminated.
## What changed
- When a group signal is denied, enumerate the group's processes and signal
members that still belong to the expected process group.
- Apply the fallback to both `SIGTERM` and `SIGKILL` during MCP stdio server
cleanup, while retaining the existing group signaling behavior elsewhere.
- Reject invalid process group IDs and avoid signaling processes that have
moved to another group.
## Testing
Added macOS tests covering cleanup with a live or exited group leader,
`SIGTERM`-resistant descendants, escalation to `SIGKILL`, and unsafe group IDs.
GitOrigin-RevId: db722475b94dece74244ce8109b3e92f6cfb202a
## What changed
- Add an opt-in `mcp_2026_07_28` protocol mode while preserving the legacy
lifecycle by default.
- Negotiate the new protocol over streamable HTTP with `server/discover`,
including bounded responses, redirect protection, and fallback only when a
response establishes that the endpoint is legacy-only.
- Require stdio servers to opt in with
`CODEX_MCP_PROTOCOL_VERSION=2026-07-28`, and add a bounded local stdio
transport for the modern lifecycle.
- Consume paginated tool, resource, and resource-template catalogs in modern
mode, reject repeated cursors, and retain discovered server identity.
- Reconnect reusable MCP clients when their selected protocol mode changes.
## Testing
- Cover HTTP JSON and SSE discovery, legacy fallback and rejection cases,
redirects, retries, response limits, and pagination.
- Cover local and executor stdio discovery, protocol markers, message limits,
and legacy compatibility.
GitOrigin-RevId: f6a78816e127d2a482292d63b91c8384f1595903
## Why
Remote executions need managed-network proxy listeners in the executor so their
loopback proxy addresses are reachable by the launched process.
## What changed
- Add a capability-gated exec-server protocol field for executor-local proxy
launch configuration, including network policy, audit metadata, and execution
attribution.
- Start the proxy while preparing a remote process, replace inherited proxy
environment variables with its local addresses, and derive the sandbox
context from its listeners.
- Keep the proxy alive until inherited output streams close, then shut it down.
- Reject unsupported remote settings such as MITM and credential injection.
## Testing
- Cover configuration round trips and rejection of unsupported settings.
- Verify executor-local startup, blocked-domain enforcement, protocol
compatibility, and proxy lifetime through process closure.
GitOrigin-RevId: c984f54e3e600aa9ebcbf8cf4574046e2c199d11
## What changed
- Apply each server's `startup_timeout_sec` (or the default) while creating the
MCP client, so the deadline also covers transport setup.
- Launch local stdio servers on a blocking task so synchronous command
resolution and process creation do not prevent the deadline from firing.
- Recognize the new client-startup timeout error and show the existing
`startup_timeout_sec` configuration hint.
## Testing
- Extend the timeout error display test to cover the client-startup timeout.
GitOrigin-RevId: 1967c62f943d55f6aa18792d4488e52c22f1e717
## Why
Managed network configures commands to use local HTTP and SOCKS proxies.
For commands delegated to the exec server, the proxy environment and the
sandbox policy were prepared separately. On macOS, that meant a command
could receive `HTTPS_PROXY=http://127.0.0.1:43123` while Seatbelt still
denied access to port `43123`.
## What changed
`NetworkProxy` now prepares the command environment and sandbox context
together from the same runtime snapshot:
```text
Prepared managed network
├── command environment: HTTPS_PROXY=http://127.0.0.1:43123
└── sandbox context: allow outbound to 127.0.0.1:43123
```
That context travels with remote exec requests. The exec server
preserves the managed proxy and CA environment, and macOS Seatbelt
allows only the prepared loopback proxy ports without enabling broad
network access or local binding.
The protocol field is optional and the existing enforcement flag remains
in place, preserving compatibility with callers that do not send the new
context.
## Why
Remote stdio MCP servers can run in an environment whose path convention
differs from the Codex host. A Windows cwd such as
`C:\Users\openai\share` is absolute for the executor but was rejected by
a POSIX orchestrator.
Built on #29501, now merged, which only clarifies the host-native
`PathUri` constructor name.
## What changed
- Deserialize MCP cwd values as `LegacyAppPathString` so config does not
apply host path rules.
- Interpret that spelling as host-native for local launches and convert
it to `PathUri` at executor launch.
- Skip host filesystem and command resolution checks for remote stdio in
`codex doctor`.
- Add host-independent config and executor-boundary coverage using the
foreign path convention for each test platform.
## Validation
- `just test -p codex-utils-path-uri -p codex-config -p codex-mcp -p
codex-rmcp-client` (408 passed)
- `just test -p codex-cli -p codex-rmcp-client` (372 passed)
- `cargo check --workspace --tests`
- `just test` (11,311 passed; 43 unrelated environment/timing failures)
- `just fix -p codex-cli -p codex-config -p codex-core -p codex-mcp -p
codex-mcp-extension -p codex-rmcp-client -p codex-tui`
## 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.
## What changed
PR #29099 stopped sending the orchestrator's concrete sandbox wrapper to
a remote exec-server. Remote commands now arrive as plain native argv.
This PR adds the next piece: Codex also sends portable sandbox intent
next to that plain argv.
For a remote unified-exec command, the request can now include:
- the canonical permission profile before local workspace-root
materialization
- the sandbox cwd and workspace roots as `PathUri` values
- Windows sandbox settings
- the legacy Landlock setting
- whether managed networking must be enforced
The important part is that symbolic entries such as `:workspace_roots`
stay symbolic while crossing the boundary. The executor can then bind
them to its own workspace-root paths instead of receiving
orchestrator-local absolute paths.
The data travels through `ExecRequest` into `ExecParams`. Older
exec-servers can still deserialize requests because the new fields have
defaults.
## Why
The orchestrator should not decide how another machine implements
sandboxing.
For example:
- a local macOS Codex would normally build a Seatbelt command
- a remote Linux executor needs a Linux sandbox command instead
The orchestrator now sends the plain command plus the policy it intended
to enforce. A later PR can let the exec-server choose and build the
correct sandbox for its own operating system.
## Important detail
This keeps the portable intent separate from the local `SandboxType`.
`SandboxType::None` is ambiguous:
- it can mean the command was explicitly approved to run without a
sandbox
- it can also mean the orchestrator host has no concrete sandbox
implementation available
Those cases are different for remote execution. This PR adds
`sandbox_requested` so an executor can still receive sandbox intent when
the orchestrator cannot build a local wrapper. Explicit unsandboxed
retries still send no sandbox context.
## Behavior today
This PR only transports the intent. The exec-server accepts the new
fields but does not apply them yet.
Remote commands therefore remain unsandboxed after this PR, just as they
are after PR #29099.
## Follow-up
The next PR will make exec-server read this portable intent, bind
symbolic workspace permissions to executor-native roots, choose the
sandbox for its own operating system, build the wrapper locally, and
then spawn the command.
## 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.
## Summary
- route each configured MCP server through an explicit per-server
`environment_id` instead of a manager-wide remote toggle
- default omitted `environment_id` to `local`, resolve named ids through
`EnvironmentManager`, and fail only the affected MCP server when an
explicit id is unknown
- keep local stdio on the existing local launcher path for now, while
named-environment stdio uses the selected environment backend and
requires an absolute `cwd`
- allow local HTTP MCP servers to keep using the ambient HTTP client
when no local `Environment` is configured; named-environment HTTP MCPs
use that environment's HTTP client
## Validation
- devbox Bazel build: `bazel build --bes_backend= --bes_results_url=
//codex-rs/cli:codex //codex-rs/rmcp-client:test_stdio_server
//codex-rs/rmcp-client:test_streamable_http_server`
- devbox app-server config matrix with real `config.toml` /
`environments.toml` files covering omitted local, explicit local,
omitted local under remote default, explicit remote stdio, local HTTP
without local env, explicit remote HTTP, local stdio without local env,
unknown explicit env, and remote stdio without `cwd`
## Why
On native Windows, running `/mcp` can leak `taskkill`'s normal
`SUCCESS:` messages into the Codex TUI while the temporary MCP inventory
process tree is being torn down. That corrupts the screen even though
MCP itself is working correctly.
Fixes#20845.
## What Changed
- Redirect the Windows-only MCP teardown `taskkill` subprocess to null
stdio so its console output cannot reach the TUI.
## How to Test
1. On native Windows, configure a stdio MCP server, for example:
```powershell
codex mcp add sequential-thinking -- npx -y
@modelcontextprotocol/server-sequential-thinking
```
2. With the latest released Codex CLI, start Codex and run `/mcp`.
3. Confirm the current behavior: `taskkill` `SUCCESS:` lines appear in
the TUI during the MCP refresh.
4. Switch to this branch's build, start Codex again, and run `/mcp`.
5. Confirm the MCP inventory still renders normally and the `taskkill`
lines no longer appear.
6. Repeat `/mcp` once more on this branch to verify the regression does
not recur on repeated inventory requests.
Targeted tests:
- `cargo test -p codex-rmcp-client`
- `cargo test -p codex-rmcp-client --test process_group_cleanup --quiet`
## Why
Several bug reports describe thread shutdown (including subagent
threads) leaving stdio MCP server processes behind. These reports all
point at the same lifecycle gap: Codex launches stdio MCP servers, but
the session-level shutdown path does not explicitly close MCP clients or
terminate the server process tree.
Fixes#12491Fixes#12976Fixes#18881Fixes#19469
## History
This is best understood as a regression/coverage gap in MCP session
lifecycle management, not as stdio MCP cleanup being absent all along.
#10710 added process-group cleanup for stdio MCP servers, but that
cleanup only runs when the `RmcpClient`/transport is dropped. The older
reports (#12491 and #12976) came after that cleanup existed, which
suggests the remaining problem was that some higher-level shutdown paths
kept the MCP manager alive or replaced it without explicitly draining
clients. The newer reports (#18881 and #19469) exposed the same family
around manager replacement and shutdown.
## What changed
- Added an explicit stdio MCP process handle in `codex-rmcp-client` so
local MCP servers terminate their process group and executor-backed MCP
servers call the executor process terminator.
- Added `RmcpClient::shutdown()` and manager-level MCP shutdown draining
so session shutdown, channel-close fallback, MCP refresh, and connector
probing stop owned MCP clients.
- Added regression coverage that starts a stdio MCP server, begins an
in-flight blocking tool call, shuts down the client, and asserts the
server process exits.
## Verification
- `cargo test -p codex-rmcp-client`
- `cargo test -p codex-mcp`
- `just fix -p codex-rmcp-client`
- `just fix -p codex-mcp`
- `just fix -p codex-core`
- Manual before/after validation with a temporary repro script:
- Pre-fix binary from `HEAD^` (`fed0a8f4fa`): reproduced the leak with
surviving MCP server and child PIDs, `survivors=[77583, 77592]`,
`leaked=true`.
- Post-fix binary from this branch (`67e318148b`): verified both MCP
processes were gone after interrupting `codex exec`, `survivors=[]`,
`leaked=false`.
## Why
Config loading had become split across crates: `codex-config` owned the
config types and merge logic, while `codex-core` still owned the loader
that assembled the layer stack. This change consolidates that
responsibility in `codex-config`, so the crate that defines config
behavior also owns how configs are discovered and loaded.
To make that move possible without reintroducing the old dependency
cycle, the shell-environment policy types and helpers that
`codex-exec-server` needs now live in `codex-protocol` instead of
flowing through `codex-config`.
This also makes the migrated loader tests more deterministic on machines
that already have managed or system Codex config installed by letting
tests override the system config and requirements paths instead of
reading the host's `/etc/codex`.
## What Changed
- moved the config loader implementation from `codex-core` into
`codex-config::loader` and deleted the old `core::config_loader` module
instead of leaving a compatibility shim
- moved shell-environment policy types and helpers into
`codex-protocol`, then updated `codex-exec-server` and other downstream
crates to import them from their new home
- updated downstream callers to use loader/config APIs from
`codex-config`
- added test-only loader overrides for system config and requirements
paths so loader-focused tests do not depend on host-managed config state
- cleaned up now-unused dependency entries and platform-specific cfgs
that were surfaced by post-push CI
## Testing
- `cargo test -p codex-config`
- `cargo test -p codex-core config_loader_tests::`
- `cargo test -p codex-protocol -p codex-exec-server -p
codex-cloud-requirements -p codex-rmcp-client --lib`
- `cargo test --lib -p codex-app-server-client -p codex-exec`
- `cargo test --no-run --lib -p codex-app-server`
- `cargo test -p codex-linux-sandbox --lib`
- `cargo shear`
- `just bazel-lock-check`
## Notes
- I did not chase unrelated full-suite failures outside the migrated
loader surface.
- `cargo test -p codex-core --lib` still hits unrelated proxy-sensitive
failures on this machine, and Windows CI still shows unrelated
long-running/timeouting test noise outside the loader migration itself.
## Summary
- Add the executor-backed RMCP stdio transport.
- Wire MCP stdio placement through the executor environment config.
- Cover local and executor-backed stdio paths with the existing MCP test
helpers.
## Stack
```text
o #18027 [6/6] Fail exec client operations after disconnect
│
@ #18212 [5/6] Wire executor-backed MCP stdio
│
o #18087 [4/6] Abstract MCP stdio server launching
│
o #18020 [3/6] Add pushed exec process events
│
o #18086 [2/6] Support piped stdin in exec process API
│
o #18085 [1/6] Add MCP server environment config
│
o main
```
---------
Co-authored-by: Codex <noreply@openai.com>
## Summary
- Move local MCP stdio process startup behind a launcher trait.
- Preserve existing local stdio behavior while making transport creation
explicit.
## Stack
```text
o #18027 [6/6] Fail exec client operations after disconnect
│
o #18212 [5/6] Wire executor-backed MCP stdio
│
@ #18087 [4/6] Abstract MCP stdio server launching
│
o #18020 [3/6] Add pushed exec process events
│
o #18086 [2/6] Support piped stdin in exec process API
│
o #18085 [1/6] Add MCP server environment config
│
o main
```
---------
Co-authored-by: Codex <noreply@openai.com>
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