Subcomponent: Relayer

The relayer's main responsibility is to fetch blocks from the Sequencer using gRPC and submit them to Celestia.

The submitter task is sent blocks asynchronously as they are fetched from the Sequencer. It converts SequencerBlock objects to Blobs that can be submitted to Celestia. This Blob structure is as follows:

pub struct Blob {
    /// A [`Namespace`] the [`Blob`] belongs to.
    pub namespace: Namespace,
    /// Data stored within the [`Blob`].
    #[serde(with = "celestia_tendermint_proto::serializers::bytes::base64string")]
    pub data: Vec<u8>,
    /// Version indicating the format in which [`Share`]s should be created from this [`Blob`].
    ///
    /// [`Share`]: crate::share::Share
    pub share_version: u8,
    /// A [`Commitment`] computed from the [`Blob`]s data.
    pub commitment: Commitment,
}

The converted Blobs are then submitted to Celestia via gRPC. It automatically retries submission for a while in case of unexpected failures, but ultimately it will quit after u32::MAX tries. It polls Celestia to ensure that the transaction it submitted was included.