Sending Commitments

Implement the Provider service as outlined in the providerapi.proto. This requires setting up a server that can manage RPC methods, with a particular emphasis on the reception of bids and response of commitment authorizations.

Utilize the ReceiveBids RPC method to listen for incoming bids from clients. This method streams bid messages to your server. The structure of the bid is as follows:

message Bid {
  option (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_schema) = {
    json_schema: {
      title: "Bid message"
      description: "Signed bid message from bidders to the provider."
      required: ["txHashes", "bidAmount", "blockNumber", "bidDigest"]
    }
    example: "{"bidDigest": "9dJinwL+FZ6B1xsIQQo8t8B0ZXJubJwY86l/Yu7yAH159QrPHU0qj2P+YFj+llbuI1ZygdxGsX8+P3byMEA5ig==", "status": "STATUS_ACCEPTED"}"
  };
  repeated string tx_hashes = 1;
  string bid_amount = 2;
  int64 block_number = 3;
  bytes bid_digest = 4;
  int64 decay_start_timestamp = 5;
  int64 decay_end_timestamp = 6;
  repeated string reverting_tx_hashes = 7;
  repeated string rawTransactions = 8;
};

The raw transactions are optionally provided by the bidder. If provided the order of the transaction hashes in txHashes will be the same as the order or the corresponding rawTransactions.

Below is an image of the flow through which bids would be received through the gRPC API

For each received bid, implement your custom logic to validate and process these bids. This could involve checking the bid’s validity and feasibility based on orderflow, computing the effective gas price, and deciding whether to accept or reject the bid.

After processing each bid, construct a BidResponse message indicating the outcome. This message should include the bid’s digest and a status indicating acceptance or rejection. At a high level, to commit to a bid, your code must send a STATUS_ACCEPTED with the bid digest specified, and correspondingly STATUS_REJECTED to reject the bid.

message BidResponse {
  option (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_schema) = {
    json_schema: {
      title: "Bid response"
      description: "Response sent by the provider with the decision on the bid received."
      required: ["bidDigest", "status"]
    }
    example: "{\"bidDigest\": \"9dJinwL+FZ6B1xsIQQo8t8B0ZXJubJwY86l/Yu7yAH159QrPHU0qj2P+YFj+llbuI1ZygdxGsX8+P3byMEA5ig==\", \"status\": \"STATUS_ACCEPTED\"}"
  };
  bytes bid_digest = 1 [(grpc.gateway.protoc_gen_openapiv2.options.openapiv2_field) = {
    description: "Digest of the bid message signed by the bidder."
  }];
  enum Status {
    STATUS_UNSPECIFIED = 0;
    STATUS_ACCEPTED = 1;
    STATUS_REJECTED = 2;
  }
  Status status = 2 [(grpc.gateway.protoc_gen_openapiv2.options.openapiv2_field) = {
    description: "Status of the bid."
  }, (buf.validate.field).enum = {
      defined_only: true,
      in: [
        1,
        2
      ]
  }];
  int64 dispatch_timestamp = 3;
};

Deploy your gRPC server on suitable infrastructure, ensuring it’s accessible to clients. Configure necessary network settings for security and connectivity. Example Server Implementation in Go:

import (
	...

	"github.com/primev/mev-commit/p2p/examples/provideremulator/client"
	providerapiv1 "github.com/primev/mev-commit/p2p/gen/go/providerapi/v1"
)

func ...() {
	...

	providerClient, _ := client.NewProviderClient(*serverAddr, logger)

	bidS, _ := providerClient.ReceiveBids()

	for {
		select {
		case bid, more := <-bidS:
			if !more {
				return
			}
			logger.Info("received new bid", "bid", bid)
			_ := providerClient.SendBidResponse(context.Background(), &providerapiv1.BidResponse{
				BidDigest: bid.BidDigest,
				Status:    providerapiv1.BidResponse_STATUS_ACCEPTED, // decide here if you want to accept or reject
        DispatchTimestamp: time.Now().Unix(),
			})
		}
	}
}