Encourages realtime prompt handling to delegate user requests to the
backend agent by default when repo inspection, commands, implementation,
or validation may help.
Co-authored-by: Codex <noreply@openai.com>
Builds on #17264.
- queues Realtime V2 `response.create` while an active response is open,
then flushes it after `response.done` or `response.cancelled`
- requests `response.create` after background agent final output and
steering acknowledgements
- adds app-server integration coverage for all `response.create` paths
Validation:
- `just fmt`
- `cargo check -p codex-app-server --tests`
- `git diff --check`
- CI green
---------
Co-authored-by: Codex <noreply@openai.com>
## Description
We reuse a guardian thread for a given user thread when we can. However,
we had always sent the full transcript history every time we made a
followup review request to an existing guardian thread.
This is especially bad for long guardian threads since we keep
re-appending old transcript entries instead of just what has changed.
The fix is to just send what's new.
**Caveat**: Whenever a thread is compacted or rolled back, we fall back
to sending the full transcript to guardian again since the thread's
history has been modified. However in the happy path we get a nice
optimization.
## Before
Initial guardian review sends the full parent transcript:
```
The following is the Codex agent history whose request action you are assessing...
>>> TRANSCRIPT START
[1] user: Please check the repo visibility and push the docs fix if needed.
[2] tool gh_repo_view call: {"repo":"openai/codex"}
[3] tool gh_repo_view result: repo visibility: public
[4] assistant: The repo is public; I now need approval to push the docs fix.
>>> TRANSCRIPT END
The Codex agent has requested the following action:
>>> APPROVAL REQUEST START
...
>>> APPROVAL REQUEST END
```
And a followup to the same guardian thread would send the full
transcript again (including items 1-4 we already sent):
```
The following is the Codex agent history whose request action you are assessing...
>>> TRANSCRIPT START
[1] user: Please check the repo visibility and push the docs fix if needed.
[2] tool gh_repo_view call: {"repo":"openai/codex"}
[3] tool gh_repo_view result: repo visibility: public
[4] assistant: The repo is public; I now need approval to push the docs fix.
[5] user: Please push the second docs fix too.
[6] assistant: I need approval for the second docs fix.
>>> TRANSCRIPT END
The Codex agent has requested the following action:
>>> APPROVAL REQUEST START
...
>>> APPROVAL REQUEST END
```
## After
Initial guardian review sends the full parent transcript (this is
unchanged):
```
The following is the Codex agent history whose request action you are assessing...
>>> TRANSCRIPT START
[1] user: Please check the repo visibility and push the docs fix if needed.
[2] tool gh_repo_view call: {"repo":"openai/codex"}
[3] tool gh_repo_view result: repo visibility: public
[4] assistant: The repo is public; I now need approval to push the docs fix.
>>> TRANSCRIPT END
The Codex agent has requested the following action:
>>> APPROVAL REQUEST START
...
>>> APPROVAL REQUEST END
```
But a followup now sends:
```
The following is the Codex agent history added since your last approval assessment. Continue the same review conversation...
>>> TRANSCRIPT DELTA START
[5] user: Please push the second docs fix too.
[6] assistant: I need approval for the second docs fix.
>>> TRANSCRIPT DELTA END
The Codex agent has requested the following next action:
>>> APPROVAL REQUEST START
...
>>> APPROVAL REQUEST END
```
The disconnect path now reuses the same teardown flow as explicit
unsubscribe, and the thread-state bookkeeping consistently reports only
threads that lost their last subscriber
https://github.com/openai/codex/issues/16895
The rollout writer now keeps an owned/monitored task handle, returns
real Result acks for flush/persist/shutdown, retries failed flushes by
reopening the rollout file, and keeps buffered items until they are
successfully written. Session flushes are now real durability barriers
for fork/rollback/read-after-write paths, while turn completion surfaces
a warning if the rollout still cannot be saved after recovery.
rhan-oai