Register ethbuilder builder

[ethbuilder-org]

Summary

Adds an entry for ethbuilder to builder-registrations.json.

• Builder name: ethbuilder
• RPC: https://rpc.ethbuilder.org
• Supported APIs: v0.1
• On-chain extra_data: ethbuilder.org/0.1
• Operator contact: @tradezermind on GitHub | @Ethbuilder_org on Telegram
• Stack: rbuilder + Reth on a dedicated bare-metal node in Nuremberg.
  Currently bidding into Aestus, Agnostic, ETHGas, Flashbots, Titan, and
  Ultrasound mainnet relays. Block share is below the 2 % criterion right
  now; this PR is to signal intent and compatibility, per the README:

  The purpose of this registry is to signal intent, compatibility,
  and agreement with the principles.

Fair Market Principles attestation

The ethbuilder operator commits to the Fair Market Principles in
fair-market-principles.md. Specifically:

• Bundles received from MEV-share matchmakers will not be sold or shared
  with other parties (no other builders, no internal or external
  searchers).
• Bundle atomicity will be preserved: either all transactions land in
  the intended order or none do. The only exception is opt-in
  conflict-free merging where the user has consented.
• Bundle privacy (including failed-trade privacy) will be respected;
  no sensitive bundle data will be shared outside the builder.
• Validity conditions will be correctly implemented, including correct
  refund transfers to the configured recipients (the upstream rbuilder
  implementation is used unmodified for this).
• We will not take actions that negatively impact bundle execution
  quality (price or refund amount).
• The default rbuilder merge-ordering algorithms mp-ordering and
  parallel-builder are in use without modification. Public
  documentation of the merging logic will be published once the ops
  dashboard is live.

Reachability

$ curl -X POST -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_sendBundle","params":[]}' \
  https://rpc.ethbuilder.org/
{"jsonrpc":"2.0","result":null,"id":1}

$ curl -X POST https://rpc.ethbuilder.org/health
ok

TLS via Let's Encrypt (expires Aug 12, 2026). Body size capped at 1 MB.
Only POST accepted; GET returns 405.

Builder pubkey

0x8c364c0bc834d517d90110cc6395901c136a3e102ced351c11318d7e48c7fe4289e816369c7b78ab5e8a539ee0614784