openai/codex · error · CodexErr

session configured event was not the first event in the stre

Error message

session configured event was not the first event in the stream

What it means

Error "session configured event was not the first event in the stream" thrown in openai/codex.

Source

Thrown at codex-rs/protocol/src/error.rs:102

    #[error("shared rollout token budget exhausted")]
    SessionBudgetExceeded,

    /// Returned by ResponsesClient when the SSE stream disconnects or errors out **after** the HTTP
    /// handshake has succeeded but **before** it finished emitting `response.completed`.
    ///
    /// The Session loop treats this as a transient error and will automatically retry the turn.
    #[error("stream disconnected before completion: {0}")]
    Stream(String),
    #[error(
        "Codex ran out of room in the model's context window. Start a new thread or clear earlier history before retrying."
    )]
    ContextWindowExceeded,
    #[error("no thread with id: {0}")]
    ThreadNotFound(ThreadId),
    #[error("agent thread limit reached")]
    AgentLimitReached { max_threads: usize },
    #[error("session configured event was not the first event in the stream")]
    SessionConfiguredNotFirstEvent,
    /// Returned by run_command_stream when the spawned child process timed out (10s).
    #[error("timeout waiting for child process to exit")]
    Timeout,
    #[error("request timed out")]
    RequestTimeout,
    /// Returned by run_command_stream when the child could not be spawned (its stdout/stderr pipes
    /// could not be captured). Analogous to the previous `CodexError::Spawn` variant.
    #[error("spawn failed: child stdout/stderr not captured")]
    Spawn,
    /// Returned by run_command_stream when the user pressed Ctrl-C (SIGINT). Session uses this to
    /// surface a polite FunctionCallOutput back to the model instead of crashing the CLI.
    #[error("interrupted (Ctrl-C). Something went wrong? Hit `/feedback` to report the issue.")]
    Interrupted,
    /// Unexpected HTTP status code.
    #[error("{0}")]
    UnexpectedStatus(UnexpectedResponseError),
    /// Invalid request.

View on GitHub (pinned to 339751715c)

When it happens

Trigger: Thrown at codex-rs/protocol/src/error.rs:102 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/0f130cf77a6e63a7. Report an issue: GitHub.