Per-block base-fee + blob-fee history export — the top-requested feed on the Seneschal data board. Up to 1024 blocks per call (?blocks=, default 300) straight from consensus via eth_feeHistory, as CSV or JSON lines (?format=csv|jsonl). Columns: block, base fee (wei + gwei), gas_used_ratio, blob base fee, blob_gas_used_ratio. Page backwards with ?newest=<block>; headers carry the consensus next-block projection. Live "gas right now" fact: GET /v1/q/base-fee ($0.001).