## Why
Remote control enrollment authorizes a desktop server, but app-server v2
did not expose the follow-up pairing operation needed to mint a
short-lived controller pairing artifact from that enrolled server.
Clients need a narrow RPC that starts pairing without exposing the
backend `serverId` or conflating pairing with websocket connection
state.
Issue: N/A; internal remote-control pairing API change.
## What Changed
Added experimental app-server v2 `remoteControl/pairing/start` with
`manualCode` input and `pairingCode`, nullable `manualPairingCode`,
`environmentId`, and Unix-seconds `expiresAt` output. The method
serializes under its own `global("remote-control-pairing")` scope and is
documented in `app-server/README.md`.
Extended the remote-control transport with private `/server/pair`
request/response types and normalized `pair_url` handling. Pairing uses
the current enrolled server bearer, refreshes that bearer when needed,
keeps backend `server_id` private, validates returned `server_id` and
`environment_id` against the current enrollment, and preserves backend
status/header/body context for failures and malformed responses.
Wired the request through `RemoteControlRequestProcessor` and
`MessageProcessor`, mapping unavailable/disabled pairing to
`invalid_request` and backend failures to internal errors.
## Verification
- `just test -p codex-app-server-transport`
- `just test -p codex-app-server
remote_control_pairing_start_returns_pairing_artifacts`
This PR brought to you via VS Code rather than Codex...
- opened `codex-rs/app-server/tests/common/mcp_process.rs`
- put the cursor on `McpServer`
- hit `F2` and renamed the symbol to `TestAppServer`
- went to the file tree
- hit enter and renamed `mcp_process.rs` to `test_app_server.rs`
- ran **Save All Files** from the Command Palette
- ran `just fmt`
The End
(Admittedly, most of the local variables for `TestAppServer` are still
named `mcp`, though.)
Anton Panasenko