Trait DirectDataFetcher 

pub trait DirectDataFetcher: Send + Sync {
    // Required method
    fn try_fetch<'life0, 'life1, 'async_trait>(
        &'life0 self,
        utterance: &'life1 str,
    ) -> Pin<Box<dyn Future<Output = Option<Result<String, String>>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;
}

Foreign-implemented data fetcher. When attached, the sidecar task gives this fetcher the utterance first; on Some(Ok(text)) the LLM is skipped entirely and the text becomes the sidecar’s answer.

On None (no match) or Some(Err(e)) (match but fetch failed), the sidecar falls through to the LLM path. Use this for the “fast data path” optimization in quip’s playbook: email/calendar queries that are pure data lookups don’t need an LLM round trip.

Implementations are typically host-side (calendar API, mail API) and should already format their output for voice narration — short, no markdown. See car_voice::format_for_voice for a minimal helper.

Required Methods

fn try_fetch<'life0, 'life1, 'async_trait>( &'life0 self, utterance: &'life1 str, ) -> Pin<Box<dyn Future<Output = Option<Result<String, String>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Try to satisfy the utterance directly without invoking the LLM.

• Some(Ok(text)) → use this as the sidecar answer.
• Some(Err(msg)) → match recognised but fetch failed; fall through to LLM (msg is logged, not surfaced).
• None → not a fast-data candidate; fall through to LLM.

Implementors