Builder Boost

Builder Boost is sidecar software that facilitates a blockbuilder or sequencer's participation in the Primev network. The diagram below outlines the module's position within a builder's local build environment.

Builder Boost Diagram

We recommend you run builder boost as an independent cloud instance if you're operations use a cloud provider.

Pre Requistes

• golang version 1.20.4+
• updated builder or execution layer with primev relay enabled
• git

Setting Up Builder Boost

Step 1. Ensure Builder is able to send payloads to builder boost

Begin by reviewing the Builder Reference Implementation instructions provided here for basic geth modifications required (~5 minutes). You can proceed to set up Builder Boost to receive block templates from your builder or execution layer after the modifications are in place.

Step 2. Download Boost via Github

Do a git clone:

$ git@github.com:primevprotocol/builder-boost.git

Step 3. Build the Boost instance

 $ cd builder-boost
 $ make all

You should now see two binaries built in the root folder:

.
├── boost
├── ...
├── searcher
...

Step 4. Run boost

We highly recommend you use systemctl to run boost, the following is a recommended systemctl file that can be used and placed in your /home/systemd/system/<filename> folder.

[Unit]
Description=boost service
After=network.target

[Service]
User=ec2-user
ExecStart=/home/ec2-user/builder-boost/boost
restart=always
Environment="ENV=sepolia"
Environment="ROLLUP_KEY=<builder-key>"
Environment="BUILDER_AUTH_TOKEN=<builder-x-boost-token>"

[Install]
WantedBy=multi-user.target

Note the BUILDER_AUTH_TOKEN should be set to the same value set for --builder-auth-key in your modified builder implementation. This token is used to authenticate your builders to boost, to ensure actors can't send fraudulent payloads.

[optional] Run builder and searcher in docker-compose

1. Copy .env.example to .env and set required variables
2. Run docker-compose up --build to run builder and searcher connected to builder

Registering your Builder or Execution Layer in the Primev Contract (on Sepolia Testnet during Pilot phase)

Open Primev Contract

Head to Update Builder Method on Etherscan. This method allows you to register your execution layer or update settings for your existing registration.

Connect your Wallet

On the top left corner of the Write Contract section press Connect to Web3. Make sure you use your builder or sequencer address (the one you use for running your execution layer / builder geth instance). This address should be funded with some ETH to cover transaction costs.

Specify Builder Parameters and Register

Use the updateBuilder method to specify 2 fields to register:

• _minimalStake: minimal amount for a data consumer to deposit to in order to authorize a connection. We suggest 0.1 ETH as a minimum.
• _minimalSubscriptionPeriod: minimal subscription period in blocks given to a data consumer for depositing minimal stake. We suggest 216000 blocks, which is about 30 days worth. If the depositor provides more than the minimum amount, the subscription period will be extended in a linear fashion.

After the required fields are specified, press the Write button and confirm the transaction using your Web3 provider. Once the transaction is confirmed, data consumers could start connecting to your builder-boost instance. Make sure to run your builder boost instance before registering a new builder or execution client.

Depositing to a builder using the Primev Contract as a Data consumer

Obtain Commitment Hash from the registered Builder

Making a deposit requires specifying a commitment hash which is unique to every searcher-builder pair. To obtain this hash you need to send a HTTP request to the builder endpoint with the specified token parameter. The token parameter is logged when running a Searcher instance, make sure you run Searcher with correct SEARCHER_KEY and BOOST_URL variables.

Obtain a Commitment Hash, assuming http://localhost:18550 is a builder boost endpoint and ABCD is a searcher token for this builder:

$ curl -H "X-Primev-Signature: ABCD" http://localhost:18550/commitment

Output will look like this:

{"commitment":"0x688d0031ba0ce02c2049786ca6fd70d04869688dd84d6310b7fdb052d199612f"}

Open the Primev Contract in Etherscan

Head to Deposit Method on Etherscan. This method allows you to deposit funds to a builder to authorize your connection.

Connect your Wallet

On the top left corner of Write Contract section press Connect to Web3. Make sure you use the address you will transact with the builder with. The contract preserves your privacy as there's a signature mechanism in place to make sure only the builder you're registering with can see your address.

Specify your deposit parameters and send the transaction

In the deposit method there are 3 fields you need to specify:

• payableAmount: the amount you want to deposit for the builder you're registering with
• _builder: the builder address you want to authorize a connection for
• _commitment: the commitment hash obtained from the previous step

After these fields are specified, press the Write button and confirm your transaction using your Web3 provider. Once the transaction is confirmed, you will be able to receive builder hints in real time.

More Links

Searcher Testing Guide - This guide walks you through the setup process for connecting searcher emulators to your boost for e2e testing and monitoring.

Builder Modifications - A detailed walkthrough with example commits, to modify a builder to add the primev relay and enable boost.