syntax = "proto3";

message HistoryEntry {
  string message_id = 1; // Unique identifier of the SDS message, as defined in `Message`
  optional bytes retrieval_hint = 2; // Optional information to help remote parties retrieve this SDS message; For example, A Waku deterministic message hash or routing payload hash
}

message SdsMessage {
  // 1 Reserved for sender/participant id
  string message_id = 2;          // Unique identifier of the message
  string channel_id = 3;          // Identifier of the channel to which the message belongs
  optional int32 lamport_timestamp = 10;    // Logical timestamp for causal ordering in channel
  repeated HistoryEntry causal_history = 11;  // List of preceding message IDs that this message causally depends on. Generally 2 or 3 message IDs are included.
  optional bytes bloom_filter = 12;         // Bloom filter representing received message IDs in channel
  optional bytes content = 20;             // Actual content of the message
}