openai/codex · error · std::io::Error

code-mode IPC frame length exceeds u32

Error message

code-mode IPC frame length exceeds u32

What it means

Error "code-mode IPC frame length exceeds u32" thrown in openai/codex.

Source

Thrown at codex-rs/code-mode-protocol/src/host/codec.rs:160

where
    W: AsyncWrite + Unpin,
{
    pub fn new(writer: W) -> Self {
        Self { writer }
    }

    /// Writes and flushes one complete frame.
    pub async fn write<T>(&mut self, message: &T) -> io::Result<()>
    where
        T: Serialize,
    {
        self.write_frame(&EncodedFrame::encode(message)?).await
    }

    /// Writes and flushes a frame encoded before it entered an I/O queue.
    pub async fn write_frame(&mut self, frame: &EncodedFrame) -> io::Result<()> {
        let length = u32::try_from(frame.payload.len()).map_err(|_| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                "code-mode IPC frame length exceeds u32",
            )
        })?;

        self.writer.write_all(&length.to_le_bytes()).await?;
        self.writer.write_all(&frame.payload).await?;
        self.writer.flush().await
    }
}

View on GitHub (pinned to 339751715c)

When it happens

Trigger: Thrown at codex-rs/code-mode-protocol/src/host/codec.rs:160 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of openai/codex@339751715c (2026-08-25). Data as JSON: /api/errors/46a9ec78f8db0946. Report an issue: GitHub.