#2747 encouraged me to audit our codebase for similar issues, as now I
am particularly suspicious that our flaky tests are due to a racy
deadlock.
I asked Codex to audit our code, and one of its suggestions was this:
> **High-Risk Patterns**
>
> All `send_*` methods await on a bounded
`mpsc::Sender<OutgoingMessage>`. If the writer blocks, the channel fills
and the processor task blocks on send, stops draining incoming requests,
and stdin reader eventually blocks on its send. This creates a
backpressure deadlock cycle across the three tasks.
>
> **Recommendations**
> * Server outgoing path: break the backpressure cycle
> * Option A (minimal risk): Change `OutgoingMessageSender` to use an
unbounded channel to decouple producer from stdout. Add rate logging so
floods are visible.
> * Option B (bounded + drop policy): Change `send_*` to try_send and
drop messages (or coalesce) when the queue is full, logging a warning.
This prevents processor stalls at the cost of losing messages under
extreme backpressure.
> * Option C (two-stage buffer): Keep bounded channel, but have a
dedicated “egress” task that drains an unbounded internal queue, writing
to stdout with retries and a shutdown timeout. This centralizes
backpressure policy.
So this PR is Option A.
Indeed, we previously used a bounded channel with a capacity of `128`,
but as we discovered recently with #2776, there are certainly cases
where we can get flooded with events.
That said, `test_shell_command_approval_triggers_elicitation` just
failed one one build when I put up this PR, so clearly we are not out of
the woods yet...
**Update:** I think I found the true source of the deadlock! See
https://github.com/openai/codex/pull/2876
Today we had a breakage in the release build that went unnoticed by CI.
Here is what happened:
- https://github.com/openai/codex/pull/2242 originally added some logic
to do release builds to prevent this from happening
- https://github.com/openai/codex/pull/2276 undid that change to try to
speed things up by removing the step to build all the individual crates
in release mode, assuming the `cargo check` call was sufficient
coverage, which it would have been, had it specified `--profile`
This PR adds `--profile` to the `cargo check` step so we should get the
desired coverage from our build matrix.
Indeed, enabling this in our CI uncovered a warning that is only present
in release mode that was going unnoticed.
The default install command causes unexpected code to be executed:
```
npm install -g @openai/codex # Alternatively: `brew install codex`
```
The problem is some environment will treat # as literal string, not
start of comment. Therefore the user will execute this instead (because
it's in backtick)
```
brew install codex
```
And then the npm command will error (because it's trying to install
package #)
POC code
```rust
use tokio::sync::mpsc;
use std::time::Duration;
#[tokio::main]
async fn main() {
println!("=== Test 1: Simulating original MCP server pattern ===");
test_original_pattern().await;
}
async fn test_original_pattern() {
println!("Testing the original pattern from MCP server...");
// Create channel - this simulates the original incoming_tx/incoming_rx
let (tx, mut rx) = mpsc::channel::<String>(10);
// Task 1: Simulates stdin reader that will naturally terminate
let stdin_task = tokio::spawn({
let tx_clone = tx.clone();
async move {
println!(" stdin_task: Started, will send 3 messages then exit");
for i in 0..3 {
let msg = format!("Message {}", i);
if tx_clone.send(msg.clone()).await.is_err() {
println!(" stdin_task: Receiver dropped, exiting");
break;
}
println!(" stdin_task: Sent {}", msg);
tokio::time::sleep(Duration::from_millis(300)).await;
}
println!(" stdin_task: Finished (simulating EOF)");
// tx_clone is dropped here
}
});
// Task 2: Simulates message processor
let processor_task = tokio::spawn(async move {
println!(" processor_task: Started, waiting for messages");
while let Some(msg) = rx.recv().await {
println!(" processor_task: Processing {}", msg);
tokio::time::sleep(Duration::from_millis(100)).await;
}
println!(" processor_task: Finished (channel closed)");
});
// Task 3: Simulates stdout writer or other background task
let background_task = tokio::spawn(async move {
for i in 0..2 {
tokio::time::sleep(Duration::from_millis(500)).await;
println!(" background_task: Tick {}", i);
}
println!(" background_task: Finished");
});
println!(" main: Original tx is still alive here");
println!(" main: About to call tokio::join! - will this deadlock?");
// This is the pattern from the original code
let _ = tokio::join!(stdin_task, processor_task, background_task);
}
```
---------
Co-authored-by: Michael Bolin <bolinfest@gmail.com>
- Introduce websearch end to complement the begin
- Moves the logic of adding the sebsearch tool to
create_tools_json_for_responses_api
- Making it the client responsibility to toggle the tool on or off
- Other misc in #2371 post commit feedback
- Show the query:
<img width="1392" height="151" alt="image"
src="https://github.com/user-attachments/assets/8457f1a6-f851-44cf-bcca-0d4fe460ce89"
/>
Adds custom `/prompts` to `~/.codex/prompts/<command>.md`.
<img width="239" height="107" alt="Screenshot 2025-08-25 at 6 22 42 PM"
src="https://github.com/user-attachments/assets/fe6ebbaa-1bf6-49d3-95f9-fdc53b752679"
/>
---
Details:
1. Adds `Op::ListCustomPrompts` to core.
2. Returns `ListCustomPromptsResponse` with list of `CustomPrompt`
(name, content).
3. TUI calls the operation on load, and populates the custom prompts
(excluding prompts that collide with builtins).
4. Selecting the custom prompt automatically sends the prompt to the
agent.
## What
Make slash commands (/init, /status, /approvals, /model) bold and white
in the welcome message for better visibility.
<img width="990" height="286" alt="image"
src="https://github.com/user-attachments/assets/13f90e96-b84a-4659-aab4-576d84a31af7"
/>
## Why
The current welcome message displays all text in a dimmed style, making
the slash commands less prominent. Users need to quickly identify
available commands when starting Codex.
## How
Modified `tui/src/history_cell.rs` in the `new_session_info` function
to:
- Split each command line into separate spans
- Apply bold white styling to command text (`/init`, `/status`, etc.)
- Keep descriptions dimmed for visual contrast
- Maintain existing layout and spacing
## Test plan
- [ ] Run the TUI and verify commands appear bold in the welcome message
- [ ] Ensure descriptions remain dimmed for readability
- [ ] Confirm all existing tests pass
This PR fixes two edge cases in managing burst paste (mainly on power
shell).
Bugs:
- Needs an event key after paste to render the pasted items
> ChatComposer::flush_paste_burst_if_due() flushes on timeout. Called:
> - Pre-render in App on TuiEvent::Draw.
> - Via a delayed frame
>
BottomPane::request_redraw_in(ChatComposer::recommended_paste_flush_delay()).
- Parses two key events separately before starting parsing burst paste
> When threshold is crossed, pull preceding burst chars out of the
textarea and prepend to paste_burst_buffer, then keep buffering.
- Integrates with #2567 to bring image pasting to windows.
`test_shell_command_approval_triggers_elicitation()` is one of a number
of integration tests that we have observed to be flaky on GitHub CI, so
this PR tries to reduce the flakiness _and_ to provide us with more
information when it flakes. Specifically:
- Changed the command that we use to trigger the elicitation from `git
init` to `python3 -c 'import pathlib; pathlib.Path(r"{}").touch()'`
because running `git` seems more likely to invite variance.
- Increased the timeout to wait for the task response from 10s to 20s.
- Added more logging.
