## Why
Remote environment connections need to honor Codex's effective outbound proxy policy, including when a rendezvous connection reconnects.
## What changed
- Pass the configured `HttpClientFactory` into remote environment transports and use `WebSocketConnector` for exec-server and rendezvous WebSockets.
- Resolve proxy routes asynchronously so these connections can use the configured system proxy.
- Add connector options that preserve Tungstenite's default TLS behavior and enable `TCP_NODELAY` for latency-sensitive rendezvous traffic.
## Testing
- Verify prepared remote environments connect through a configured system proxy.
- Verify initial and reconnected encrypted relay peers use the system proxy.
- Cover default TLS selection and opt-in `TCP_NODELAY` behavior in the WebSocket client.
GitOrigin-RevId: 8a8da2116e37cb3a891269d0c0b037986fecdd3c
## Why
System proxy discovery can block, and delegating fallback to each transport can repeat discovery or apply inconsistent environment proxy behavior.
## What changed
- Resolve unavailable system proxy decisions to an explicit environment proxy or direct route, including `NO_PROXY` settings and WebSocket-specific fallbacks.
- Add asynchronous system proxy resolution that uses cached decisions first and serializes blocking platform lookups on Windows and macOS.
- Preserve `NO_PROXY` handling for WebSocket connections, including HTTP and HTTPS proxies, and hash proxy cache keys on every platform.
## Testing
- Add coverage for explicit environment fallback, cached asynchronous resolution, and proxied or bypassed WebSocket connections.
GitOrigin-RevId: 3b7cf170dcfe639eec53c3c1514f92bfcf13e7e9
## Why
The route-aware WebSocket connection setup in #31441 is transport
infrastructure rather than Responses API protocol logic. Landing it
first in a dedicated crate keeps `codex-api` focused on request and
response behavior and makes the transport reusable by future WebSocket
clients.
WebSockets must also apply the same effective outbound proxy and
custom-CA policy as HTTP without disabling the lower-latency WebSocket
path. Requiring an `HttpClientFactory` when constructing the connector
makes proxy-policy resolution part of the API instead of an optional
call-site convention.
This PR is an independent prerequisite based directly on `main`. After
it merges, #31441 can rebase onto it and replace its in-crate connector
with this API.
## What changed
- Add a new `codex-websocket-client` workspace crate with a
`WebSocketConnector` constructed from the effective `HttpClientFactory`.
- Resolve every destination through that factory before connecting, then
support direct connections, transport-default routing, HTTP proxies, and
TLS-encrypted HTTPS proxies.
- Preserve custom-CA trust for proxy and target TLS handshakes and
preserve Happy Eyeballs fallback for explicit direct and proxy routes.
- Expose an established `WebSocketConnection` as a uniform `Stream` and
`Sink`, hiding route-specific transport types from protocol clients.
- Add focused integration-style coverage for the public connector and
message stream, real WSS over direct and CONNECT routes, implicit and
explicit HTTPS proxy ports, and stalled-address-family fallback.
## Review guide
1. `codex-rs/websocket-client/src/lib.rs` defines the small public API
and the factory-required policy invariant.
2. `codex-rs/websocket-client/src/dialer.rs` contains DNS, TCP, proxy
tunneling, TLS, and WebSocket handshake setup.
3. `codex-rs/websocket-client/src/dialer_tests.rs` verifies the public
stream, direct and proxied WSS paths, HTTPS port preservation, and Happy
Eyeballs timing.
4. There is intentionally no consumer migration here; #31441 will become
the first consumer after this prerequisite merges.
## Test plan
- `cargo check -p codex-websocket-client --tests`
- `just test -p codex-websocket-client`
- `cargo shear`
- `just bazel-lock-check`
