At and after Azul activation, block production and import use the following Engine API methods:

• engine_forkchoiceUpdatedV3 for starting block builds and forkchoice synchronization.
• engine_getPayloadV5 for fetching built payloads.
• engine_newPayloadV4 for importing payloads into the execution engine.

engine_getPayloadV5 returns a V5 envelope, but the contained execution payload is still V4-shaped. As a result, payload insertion continues through engine_newPayloadV4 (there is no engine_newPayloadV5 path used by Base Azul clients).

Azul constraints for this flow:

• Blob-related Engine API inputs are constrained to empty values:
• expectedBlobVersionedHashes MUST be an empty array.
• blobsBundle in engine_getPayloadV5 responses is expected to be empty.
• executionRequests in engine_newPayloadV4 MUST be an empty array.

Use the registry as the source of accepted TEE signer identities instead of hard-coding Nitro prover signers.