I’m getting signature is required / invalid flashbots signature from https://relay-sepolia.flashbots.net even with the official SDK and minimal payload. It does verifies the signature against the Mainnet relay though.
I’ve verified:
- exact body bytes signed == bytes sent
- X-Flashbots-Signature header is present on the wire
- SDK (@flashbots/ethers-provider-bundle) with eth_sendBundle still returns signature is required
Is there any allowlist/registration or Sepolia-specific relay policy for auth keys? If yes, how do I register the key?