Function start_indexer 

pub async fn start_indexer(
    path: impl AsRef<Path>,
    indexer_args: IndexerArgs,
    client_args: ClientArgs,
    db_options: DbOptions,
    ingestion_config: IngestionConfig,
    config: ServiceConfig,
    registry: &Registry,
) -> Result<Service>

Standalone-binary entry point. Opens the database at path, constructs an Indexer from ClientArgs-driven ingestion / streaming clients, registers every pipeline that is enabled in config.pipeline, and runs the resulting indexer.

The embedded-fullnode path bypasses this helper and constructs Indexer::from_store directly with its own IngestionClientTrait / CheckpointStreamingClient implementations.