## 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.
## Why
`codex exec-server` should keep the existing public `ws://IP:PORT` URL
shape while serving that websocket connection through an HTTP upgrade
path internally. That keeps the client-facing configuration simple and
allows the listener to work through intermediate HTTP-aware
infrastructure.
## What changed
- keep the emitted and configured exec-server URL as `ws://IP:PORT`
- serve that websocket endpoint through Axum HTTP upgrade handling on
`/`
- expose `GET /readyz` from the same listener for readiness checks
- route upgraded Axum websocket streams through the shared JSON-RPC
connection machinery
- initialize the rustls crypto provider before websocket client
connections
- preserve inbound binary websocket JSON-RPC parsing for compatibility
with the prior transport behavior
## Verification
- `cargo test -p codex-exec-server --test health --test process --test
websocket --test initialize --test exec_process`
## Why
The environment-backed exec-server transport currently hardcodes 5
second connect and initialize timeouts in `client_transport.rs`. That is
short for SSH-backed stdio environments and remote websocket
environments, and there is currently no way to raise those values from
`CODEX_HOME/environments.toml`.
This stacked follow-up raises the default environment transport timeouts
and lets each configured environment override them in
`environments.toml`.
## What Changed
- raise the default environment transport connect and initialize
timeouts from 5s to 10s
- store concrete timeout values on `ExecServerTransportParams` instead
of hardcoding them in `connect_for_transport(...)`
- add `connect_timeout_sec` and `initialize_timeout_sec` to
`[[environments]]` entries in `environments.toml`
- apply parse-time defaults so runtime transport code receives fully
resolved timeout values
- reject `connect_timeout_sec` on stdio environments because it only
applies to websocket transports
- extend parser tests to cover the new fields and defaults
## Stack
- base: https://github.com/openai/codex/pull/21794
- this PR: configurable environment transport timeouts
## Validation
- `cd
/Users/starr/code/codex-worktrees/exec-env-timeouts-config-20260508/codex-rs
&& just fmt`
- not run: tests
---------
Co-authored-by: Codex <noreply@openai.com>
## Why
Configured environments need to connect to exec-server instances that
are not necessarily already listening on a websocket URL. A
command-backed stdio transport lets Codex start an exec-server process,
speak JSON-RPC over its stdio streams, and clean up that child process
with the client lifetime.
**Stack position:** this is PR 2 of 5. It builds on the server-side
stdio listener from PR 1 and provides the client transport used by later
environment/config PRs.
## What Changed
- Add `ExecServerTransport` variants for websocket URLs and stdio shell
commands.
- Add stdio command connection support for `ExecServerClient`.
- Move websocket/stdio transport setup into `client_transport.rs` so
`client.rs` stays focused on shared JSON-RPC client, session, HTTP, and
notification behavior.
- Tie stdio child process cleanup to the JSON-RPC connection lifetime
with a RAII lifetime guard.
- Keep existing websocket environment behavior by adapting URL-backed
remotes to `ExecServerTransport::WebSocketUrl`.
## Stack
- 1. https://github.com/openai/codex/pull/20663 - Add stdio exec-server
listener
- **2. This PR:** https://github.com/openai/codex/pull/20664 - Add stdio
exec-server client transport
- 3. https://github.com/openai/codex/pull/20665 - Make environment
providers own default selection
- 4. https://github.com/openai/codex/pull/20666 - Add CODEX_HOME
environments TOML provider
- 5. https://github.com/openai/codex/pull/20667 - Load configured
environments from CODEX_HOME
Split from original draft: https://github.com/openai/codex/pull/20508
## Validation
Not run locally; this was split out of the original draft stack and then
refactored to separate transport setup from the base client.
---------
Co-authored-by: Codex <noreply@openai.com>
