Files
codex/codex-rs/app-server-test-client
Jiaming Zhang 5f4d0ec343 [codex] request desktop attestation from app (#20619)
## Summary

TL;DR: teaches `codex-rs` / app-server to request a desktop-provided
attestation token and attach it as `x-oai-attestation` on the scoped
ChatGPT Codex request paths.

![DeviceCheck attestation
interface](https://raw.githubusercontent.com/openai/codex/dev/jm/devicecheck-diagram-assets/pr-assets/devicecheck-attestation-interface.png)

## Details

This PR teaches the Codex app-server runtime how to request and attach
an attestation token. It does not generate DeviceCheck tokens directly;
instead, it relies on the connected desktop app to advertise that it can
generate attestation and then asks that app for a fresh header value
when needed.

The flow is:

1. The Codex desktop app connects to app-server.
2. During `initialize`, the app can advertise that it supports
`requestAttestation`.
3. Before app-server calls selected ChatGPT Codex endpoints, it sends
the internal server request `attestation/generate` to the app.
4. app-server receives a pre-encoded header value back.
5. app-server forwards that value as `x-oai-attestation` on the scoped
outbound requests.

The code in this repo is mostly protocol and runtime plumbing: it adds
the app-server request/response shape, introduces an attestation
provider in core, wires that provider into Responses / compaction /
realtime setup paths, and covers the intended scoping with tests. The
signed macOS DeviceCheck generation remains owned by the desktop app PR.

## Related PR

- Codex desktop app implementation:
https://github.com/openai/openai/pull/878649

## Validation

<details>
<summary>Tests run</summary>

```sh
cargo test -p codex-app-server-protocol
cargo test -p codex-core attestation --lib
cargo test -p codex-app-server --lib attestation
```

Also ran:

```sh
just fix -p codex-core
just fix -p codex-app-server
just fix -p codex-app-server-protocol
just fmt
just write-app-server-schema
```

</details>

<details>
<summary>E2E DeviceCheck validation</summary>

First validated the signed desktop app boundary directly: launched a
packaged signed `Codex.app`, sent `attestation/generate`, decoded the
returned `v1.` attestation header, and validated the extracted
DeviceCheck token with `personal/jm/verify_devicecheck_token.py` using
bundle ID `com.openai.codex`. Apple returned `status_code: 200` and
`is_ok: true`.

Then ran the fuller app + app-server flow. The packaged `Codex.app`
launched a current-branch app-server via `CODEX_CLI_PATH`, and a local
MITM proxy intercepted outbound `chatgpt.com` traffic. The app-server
requested `attestation/generate` from the real Electron app process, and
the intercepted `/backend-api/codex/responses` traffic included
`x-oai-attestation` on both routes:

```text
GET  /backend-api/codex/responses  Upgrade: websocket  x-oai-attestation: present
POST /backend-api/codex/responses  Upgrade: none       x-oai-attestation: present
```

The captured header decoded to a DeviceCheck token that also validated
with Apple for `com.openai.codex` (`status_code: 200`, `is_ok: true`,
team `2DC432GLL2`).

</details>

---------

Co-authored-by: Codex <noreply@openai.com>
2026-05-08 12:36:02 -07:00
..

App Server Test Client

Quickstart for running and hitting codex app-server.

Quickstart

Run from <reporoot>/codex-rs.

# 1) Build debug codex binary
cargo build -p codex-cli --bin codex

# 2) Start websocket app-server in background
cargo run -p codex-app-server-test-client -- \
  --codex-bin ./target/debug/codex \
  serve --listen ws://127.0.0.1:4222 --kill

# 3) Call app-server (defaults to ws://127.0.0.1:4222)
cargo run -p codex-app-server-test-client -- model-list

Watching Raw Inbound Traffic

Initialize a connection, then print every inbound JSON-RPC message until you stop it with Ctrl+C:

cargo run -p codex-app-server-test-client -- watch

Testing Thread Rejoin Behavior

Build and start an app server using commands above. The app-server log is written to /tmp/codex-app-server-test-client/app-server.log

1) Get a thread id

Create at least one thread, then list threads:

cargo run -p codex-app-server-test-client -- send-message-v2 "seed thread for rejoin test"
cargo run -p codex-app-server-test-client -- thread-list --limit 5

Copy a thread id from the thread-list output.

2) Rejoin while a turn is in progress (two terminals)

Terminal A:

cargo run --bin codex-app-server-test-client -- \
  resume-message-v2 <THREAD_ID> "respond with thorough docs on the rust core"

Terminal B (while Terminal A is still streaming):

cargo run --bin codex-app-server-test-client -- thread-resume <THREAD_ID>