Block Submission

External builders with enterprise plan or above are allowed to submit blocks to bloXroute regulated relay on Ethereum Mainnet. bloXroute relay supports Relay API spec, and block builders can submit blocks to the /relay/v1/builder/blocks endpoint. Builder must include their authorization header (from bloXroute account portal) in the http request header, like -H "Authorization: <YOUR-AUTHORIZATION-HEADER>" , when submitting blocks to bloXroute relay.

Builders with Enterprise plan or above can start submitting blocks to bloXroute now! Builders with Ultra tier will be able to get from bloXroute MEV bundles and private transactions to be added to their blocks.

Dehydrated block submission

You can enable dehydration on block submissions to optimize bandwidth utilization:

• For HTTP: Add an X-Hydrate header to your submission

• For gRPC: Set the hydrate boolean field on SubmitBlockRequest

For blob handling, the HTTP submission model now supports the NewItems field with the following structure:

type FuluExtendedBlobsBundle struct {
	Commitments []deneb.KZGCommitment    `json:"commitments" ssz-max:"4096" ssz-size:"?,48"`
	Proofs      []deneb.KZGProof         `json:"proofs" ssz-max:"33554432" ssz-size:"?,48"`
	Blobs       []deneb.Blob             `json:"blobs" ssz-max:"4096" ssz-size:"?,131072"`
	NewItems    []*FuluHydrationBlobItem `json:"new_items" ssz-max:"4096" ssz-size:"?,137268"`
}

type FuluHydrationBlobItem struct {
	Proof      []deneb.KZGProof    `json:"proof" ssz-max:"128" ssz-size:"?,48"`
	Commitment deneb.KZGCommitment `json:"commitment" ssz-size:"48"`
	Blob       deneb.Blob          `json:"blob" ssz-size:"131072"`
}

Similarly, the gRPC submission model introduces the NewItems field that can be explored here. Blob items submitted via NewItems are cached locally using their commitment as a key, and the commitments at the blob bundle level are used to reference them in subsequent submissions.

Dehydrated block submissions are fully compatible with the similar features of Titan and Ultrasound supporting both transaction and blob deltas.

Block Submission Rate Limits and Restriction

Plan	Block Simulation	Block Cancellation
VIP (Contact bloXroute)	Dedicated Bare Metal Server or Skip Simulation	Supported
Ultra bundle	Dedicated Bare Metal Server	Supported
Elite bundle	Shared Cloud Server	Unsupported
Enterprise bundle	Shared Cloud Server	Unsupported