## Why
`features.respect_system_proxy` already routes authentication traffic
through the OS proxy APIs, but it does not affect the primary inference
path. That leaves users behind OS-managed proxies unable to send normal
Responses API requests even after login succeeds.
This PR is the first product-path migration onto the route-aware
transport introduced in #31323 and refined in #31331. It also
establishes the construction pattern for later migrations: the effective
feature state is resolved once into a required HTTP client factory
rather than represented by an optional per-call setting.
The scope remains limited to the two HTTP Responses endpoints;
WebSockets, model discovery, memories, realtime, and file uploads remain
follow-up migrations.
## What changed
- Replace the optional proxy marker with an explicit
`OutboundProxyPolicy::{ReqwestDefault, RespectSystemProxy}` and a
required `HttpClientFactory`. The policy has no default, and the
lower-level route-aware reqwest builder is now private.
- Have `Config` construct the factory from the effective feature state
and require every `ModelClient` constructor to receive it. There is no
optional setter or implicit `None` fallback.
- Build HTTP clients for `/responses` and `/responses/compact` with
`ClientRouteClass::Api`, using the complete destination URL so PAC rules
can make URL-specific decisions.
- Layer route-aware selection onto Codex's existing default headers,
Cloudflare cookie store, custom CA handling, and sandbox no-proxy
behavior.
- Add an integration test that loads `features.respect_system_proxy`
through `config.toml`, creates a real Codex session, and verifies that
both a normal Responses turn and remote compaction reach an isolated
local proxy.
## Review guide
1. `http-client/src/outbound_proxy.rs` defines the mandatory
policy/factory boundary and keeps route resolution private.
2. `core/src/config/mod.rs`, `core/src/session/session.rs`, and
`core/src/client.rs` show the compile-time invariant: effective config
creates the factory, and `ModelClient` cannot be constructed without
one.
3. `login/src/auth/default_client.rs` preserves existing default-client
behavior while accepting the required factory for migrated routes.
4. `core/src/client.rs` switches only streaming Responses and remote
compaction HTTP transports to the API route class.
5. `core/tests/suite/responses_api_system_proxy.rs` is the behavioral
regression boundary. Its Linux subprocess deliberately sets the CGI
marker that disables reqwest's implicit environment-proxy handling, so
the test fails if session wiring or either Responses call site falls
back to the default client.
## Test plan
- `cargo check --tests -p codex-http-client -p codex-login -p
codex-core`
- `just test -p codex-login`
- `just test -p codex-core
respect_system_proxy_feature_resolves_enabled`
- Existing `compact_uses_bearer_after_agent_identity_session_fallback`
coverage passes with the new transport construction.
- New Linux integration coverage:
`responses_and_compact_use_enabled_system_proxy`
- `just bazel-lock-check`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/31335).
* #31342
* __->__ #31335
## Why
#31323 introduces `codex-http-client` and leaves compatibility
re-exports in `codex-client`. Low-level HTTP consumers should depend on
the crate that now owns those APIs rather than continuing through the
transitional compatibility layer.
This stacked follow-up makes that ownership explicit and moves the
repository toward enforcing the abstraction without mixing call-site
churn into the extraction itself.
## What changed
- Switched `codex-backend-client`, `codex-cloud-tasks`,
`codex-exec-server`, `codex-login`, and `codex-model-provider` from
`codex-client` to `codex-http-client` where they only use low-level HTTP
APIs.
- Added the direct dependency to `codex-api` for its custom-CA request
and websocket paths while retaining `codex-client` for higher-level
retry and transport policy.
- Updated imports and normalized login's internal client type name from
`CodexHttpClient` to `HttpClient`, while preserving its existing
`CodexRequestBuilder` re-export.
- Updated `Cargo.lock` to reflect the new direct dependency edges.
## Review guide
This PR is intentionally mechanical: 20 files and 92 changed lines, with
no runtime logic changes. The largest diff is
`codex-rs/login/src/auth/default_client.rs`, where the only
semantic-looking changes are type and import renames. The remaining
source changes replace `codex_client` import paths with
`codex_http_client`; the manifest and lockfile changes mirror those
imports.
## Test plan
- Compile-checked `codex-api`, `codex-backend-client`,
`codex-cloud-tasks`, `codex-exec-server`, `codex-login`, and
`codex-model-provider` together.
## Summary
Stacked on #26706.
Adds the shared auth/system-proxy contract that later platform resolver
PRs plug into. This PR moves Codex-owned auth and startup HTTP clients
through a common route-aware boundary, but does not yet add Windows or
macOS system proxy resolution.
The default path remains unchanged when `respect_system_proxy` is absent
or disabled.
## Implementation
- Adds `codex-client/src/outbound_proxy.rs` with the shared
route-selection model:
- `OutboundProxyConfig`;
- `ClientRouteClass`;
- `RouteFailureClass`;
- `build_reqwest_client_for_route`.
- Preserves the existing reqwest/default-client behavior when no route
config is supplied.
- Uses the fixed MVP routing policy when route config is supplied:
platform system/PAC/WPAD discovery, then explicit env proxy variables,
then direct connection.
- Keeps platform-specific system discovery behind the shared client
boundary. This PR provides the contract and fallback behavior; later
resolver PRs plug in Windows and macOS discovery.
- Adds `login::AuthRouteConfig` so auth call sites depend on a small
policy type instead of platform resolver details.
- Maps the resolved `Config.respect_system_proxy` boolean into
`AuthRouteConfig` for auth-owned clients.
- Wires the route config through browser login, device-code login,
access-token login, login status, logout/revoke, token refresh, API-key
exchange, app-server account login, TUI/app startup, cloud-config
bootstrap, cloud tasks, plugin auth, and exec startup config loading.
## End-user behavior
- No behavior changes by default.
- When `respect_system_proxy = true`, auth-owned clients opt into the
shared route-aware client path.
- On platforms without a resolver implementation in this PR, system
discovery is unavailable and the route-aware path falls back to explicit
env proxy handling, then direct connection.
- Custom CA handling remains separate from proxy route selection and
still runs through the shared client builder.
- No proxy URLs, PAC contents, or resolved platform details are exposed
through the public config surface introduced here.
## Tests
Adds or updates coverage for:
- preserving default auth-client fallback behavior when no route config
is provided;
- injected environment-proxy fallback without mutating process
environment;
- existing login-server E2E flows using explicit `auth_route_config:
None` to guard unchanged default behavior;
- updated auth manager, login, logout, cloud-config, startup, and
plugin-auth call sites passing route config explicitly.
Michael Bolin