Function encode_data_response 

pub fn encode_data_response(
    response: &DataResponse,
) -> Result<EncodedPayload, EncodeError>

Encodes a [DataResponse] envelope by dispatching on the variant.

send_data_response hands the bus tap a [DataResponse] wrapper, so the tap dispatches by the wrapper’s std::any::TypeId and the inner variants never reach their bare-type encoders. The dispatcher unwraps each variant, encodes the inner struct, and stamps the inner-variant tag so forensics scans see entries identical to a bare-type capture path.

Each variant carries a correlation_id (UUID4) pairing the response with the originating RequestCommand::request_id. IndexKind has no matching variant today, so every variant emits zero sidecar indices, mirroring the [PositionStatusReport] and [AccountState] precedents.

The [DataResponse::Data] and [DataResponse::Book] variants carry payloads that are not directly serializable: [CustomDataResponse] holds an Arc<dyn Any> and [BookResponse] holds a [nautilus_model::orderbook::OrderBook] without serde derives. The dispatcher serializes the audit-relevant metadata for those two variants via local borrowed wrapper structs (the encode_order_with_fills precedent) and omits the opaque payload. BookResponse is state-affecting on the data engine path (handle_book_response clones the book into the cache); a follow-up that adds serde to OrderBook/BookLadder can replace the metadata wrapper with full payload capture without changing the dispatcher contract.

Errors

Returns the inner encoder’s EncodeError when MessagePack rejects the inner payload.