## Why
#28522 routes selected-plugin HTTP MCP traffic through the owning
executor, but OAuth bootstrap and refresh still used host-local clients.
Executor-only servers therefore cannot complete discovery or login
through the same network boundary as the MCP connection.
## What changed
- adapt `codex_exec_server::HttpClient` to RMCP 1.8's `OAuthHttpClient`
contract
- let RMCP own discovery, dynamic registration, PKCE, token exchange,
and refresh
- route auth status, persisted-token startup, and app-server login
through the server runtime while preserving the existing local discovery
path
- add optional `threadId` to `mcpServer/oauth/login` and echo it in the
completion notification
- implement RMCP's redirect policy and 1 MiB OAuth response limit over
executor HTTP
- cover selected-thread OAuth discovery and login through an
executor-only route
Depends on #28522.
## Why
Exec-server JSON-RPC calls can cross local and remote transports, but
trace context stopped at the RPC boundary. That made client and server
work difficult to correlate when diagnosing latency or failures.
## What changed
- Propagate the current W3C trace context on outbound JSON-RPC requests.
- Parent inbound request spans from received trace context.
- Record the received JSON-RPC method on server spans and keep each span
open through response enqueue.
- Add only the OTEL dependencies required by the exec-server crate.
## Stack
Review and land this stack in order:
1. #27466 — trace exec-server JSON-RPC requests **(this PR)**
2. #27467 — record bounded connection, request, and process lifecycle
metrics
3. #27470 — observe remote registration and Noise rendezvous lifecycle
## Validation
- `just test -p codex-exec-server --lib` (153 passed)
- `just bazel-lock-check`
- `just fix -p codex-exec-server`
Stack 1 of 3. Follow-ups: #29842 and #29844.
## What changes
Adds a general bounded `fs/walk` operation to the exec server.
The operation returns file and directory entries plus recoverable
per-path errors. It skips symlinks, preserves the existing filesystem
sandbox routing, and enforces depth, directory, entry, and response-size
limits.
This PR only defines and wires the filesystem operation. It does not
change any callers yet.
## Why
The app-server and exec-server expose separate JSON-RPC APIs, but
exec-server currently sources its serialized protocol and envelope types
through app-server-oriented code. Giving each API an explicit owner
makes the crate boundary legible without introducing shared generic
envelopes.
## What changed
- Added `codex-exec-server-protocol` to own exec DTOs, process IDs, and
JSON-RPC envelopes.
- Updated exec-server clients, transports, handlers, and tests to use
the new crate.
- Exposed app-server's existing JSON-RPC types through a public `rpc`
module while retaining root re-exports.
- Preserved existing wire shapes, including exec `PathUri` behavior.
## Stack
This is PR 1 of 6. Next: [PR
#29721](https://github.com/openai/codex/pull/29721), which moves auth
mode below the app wire boundary.
## Validation
- Exec-server protocol and server coverage passed in the focused
protocol test runs.
- App-server protocol schema fixtures passed.
jifandGitHub
richardopenaiandGitHub
Adam Perry @ OpenAIandGitHub