`experimental_thread_store_endpoint` is no longer supported;

Error message

`experimental_thread_store_endpoint` is no longer supported; remove it from config.toml

What it means

Error "`experimental_thread_store_endpoint` is no longer supported; remove it from config.toml" thrown in openai/codex.

Source

Thrown at codex-rs/core/src/config/mod.rs:3131

            cfg,
            overrides,
            codex_home,
            config_layer_stack,
        )
        .await
    }

    pub(crate) async fn load_config_with_layer_stack(
        fs: &dyn ExecutorFileSystem,
        mut cfg: ConfigToml,
        overrides: ConfigOverrides,
        codex_home: AbsolutePathBuf,
        config_layer_stack: ConfigLayerStack,
    ) -> std::io::Result<Self> {
        // Keep the large config-construction future off small test thread stacks.
        Box::pin(async move {
        if cfg.experimental_thread_store_endpoint.is_some() {
            return Err(std::io::Error::new(
                std::io::ErrorKind::InvalidInput,
                "`experimental_thread_store_endpoint` is no longer supported; remove it from config.toml",
            ));
        }

        validate_model_providers(&cfg.model_providers)
            .map_err(|message| std::io::Error::new(std::io::ErrorKind::InvalidInput, message))?;
        if let Some(responses_api_metadata) = cfg.responses_api_metadata.as_ref() {
            validate_extra_metadata(responses_api_metadata.iter()).map_err(|message| {
                std::io::Error::new(std::io::ErrorKind::InvalidInput, message)
            })?;
        }
        validate_managed_developer_instructions(
            config_layer_stack
                .requirements()
                .additional_developer_instructions
                .as_ref(),
        )?;

View on GitHub (pinned to 339751715c)

Solutions

Remove `experimental_thread_store_endpoint` from config.toml; it is no longer supported.

When it happens

Trigger: Thrown at codex-rs/core/src/config/mod.rs:3131 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/14f0bce852967ffb. Report an issue: GitHub.