BUILDER GUIDE

Submit blocks to the Pulsechain MEV relay and compete for validator selection

API ENDPOINT

https://relay-api.9mm.pro

ENDPOINTS

GET /relay/v1/builder/validators

Get list of registered validators for upcoming slots

curl https://relay-api.9mm.pro/relay/v1/builder/validators

POST /relay/v1/builder/blocks

Submit a block for a specific slot

curl -X POST \
  -H "Content-Type: application/json" \
  -d @block_submission.json \
  https://relay-api.9mm.pro/relay/v1/builder/blocks

GET /eth/v1/builder/status

Check relay health status

curl https://relay-api.9mm.pro/eth/v1/builder/status

BLOCK SUBMISSION FORMAT

{
  "message": {
    "slot": "1234567",
    "parent_hash": "0x...",
    "block_hash": "0x...",
    "builder_pubkey": "0x...",
    "proposer_pubkey": "0x...",
    "proposer_fee_recipient": "0x...",
    "gas_limit": "30000000",
    "gas_used": "15000000",
    "value": "1000000000000000000"
  },
  "execution_payload": {
    "parent_hash": "0x...",
    "fee_recipient": "0x...",
    "state_root": "0x...",
    "receipts_root": "0x...",
    "logs_bloom": "0x...",
    "prev_randao": "0x...",
    "block_number": "12345678",
    "gas_limit": "30000000",
    "gas_used": "15000000",
    "timestamp": "1234567890",
    "extra_data": "0x...",
    "base_fee_per_gas": "1000000000",
    "block_hash": "0x...",
    "transactions": ["0x..."],
    "withdrawals": []
  },
  "signature": "0x..."
}

RESPONSE CODES

Code	Meaning
200	Success - block accepted
400	Bad request - invalid payload
500	Server error

PULSECHAIN PARAMETERS

Parameter	Value
Chain ID	369
Slot Time	10 seconds
Slots per Epoch	32
Genesis Fork Version	0x00000369
Capella Fork Version	0x0000036c

DATA API (READ-ONLY)

GET /relay/v1/data/bidtraces/proposer_payload_delivered

Get delivered payloads

curl "https://relay-api.9mm.pro/relay/v1/data/bidtraces/proposer_payload_delivered?limit=10"

GET /relay/v1/data/bidtraces/builder_blocks_received

Get received builder bids

curl "https://relay-api.9mm.pro/relay/v1/data/bidtraces/builder_blocks_received?slot=1234567"

BEST PRACTICES

Monitor duties - Poll /relay/v1/builder/validators regularly
Submit early - Submit blocks as early as possible in the slot
Competitive bids - Higher value blocks are more likely selected
Handle errors - Implement retry logic for failed submissions

API DOCUMENTATION

Full API specification: flashbots.github.io/relay-specs

relay.9mm.pro • validator guide