## What changed
- Probe the configured Responses inference endpoint with Codex's route-aware HTTP client, including configured proxy and custom CA behavior.
- Classify TLS, proxy authentication, proxy configuration, resolution, and timeout failures into actionable diagnostics.
- Report privacy-safe macOS system proxy state and suggest enabling `respect_system_proxy` when a configured proxy is otherwise unused.
- Preserve system-root fallback when a custom CA is invalid, and account for provider-specific API key configuration when selecting the probe route.
## Testing
- Cover inference endpoint selection, invalid custom CA fallback, proxy authentication failures, TLS classification, and macOS proxy reporting.
GitOrigin-RevId: c30a3ca5a332119e2b2f8c65341ef9b2251a28a2
## 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
Codex-owned HTTP construction currently lives in `codex-client`
alongside higher-level retry, SSE, and request-telemetry policy. That
makes it difficult to apply shared network behavior consistently across
crates, particularly system proxy/PAC resolution, custom CA handling,
and the ChatGPT Cloudflare cookie policy. It also leaves no clear crate
boundary for migrating direct `reqwest` usage behind a single Codex
abstraction.
This change establishes that low-level ownership boundary without
changing request behavior. It builds on the system proxy support
introduced in #26706, #26707, #26708, and #26709.
## What changed
- Added `codex-rs/http-client` as the `codex-http-client` crate.
- Moved request/response types, the concrete `reqwest` transport, custom
CA handling, Cloudflare cookie policy, and macOS/Windows proxy
resolution into the new crate.
- Kept retry, SSE, and request-telemetry policy in `codex-client`.
- Re-exported the moved API from `codex-client`, including compatibility
aliases for `CodexHttpClient` and `CodexRequestBuilder`, so existing
consumers do not change in this PR.
- Moved the existing proxy and custom-CA tests with their
implementation.
## Scope boundary
This PR deliberately stops at the crate extraction. Stacked follow-up
#31331 migrates downstream imports from `codex-client` to
`codex-http-client`, keeping this change focused on ownership and
compatibility rather than mixing in repository-wide call-site churn.
## Review guide
GitHub reports 30 changed files, of which 17 are detected renames. A
useful review order is:
1. Review the new boundary in `codex-rs/http-client/Cargo.toml` and
`codex-rs/http-client/src/lib.rs`.
2. Review `codex-rs/codex-client/Cargo.toml` and
`codex-rs/codex-client/src/lib.rs` for what remains in the higher-level
crate and how compatibility is preserved.
3. Treat the renamed implementation and test files as moves. Their
meaningful edits are limited to crate paths and normalizing the new
crate's type names to `HttpClient` and `RequestBuilder`.
4. Review `codex-rs/Cargo.toml`, `codex-rs/Cargo.lock`, and the two
`BUILD.bazel` files as mechanical workspace integration.
## Test plan
- `just test -p codex-http-client -p codex-client` (38 tests)
- Compile-checked the unchanged `codex-api`, `codex-backend-client`,
`codex-cloud-tasks`, `codex-exec-server`, `codex-login`, and
`codex-model-provider` consumers against the compatibility re-exports.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/31323).
* #31331
* __->__ #31323
