Per-slot builder bids + realised proposer payment from the Seneschal shadow recorder, as CSV or JSON lines (?format=csv|jsonl). Range: ?from_block=&to_block= (max 100000 blocks) or ?window_ms= (max 30d). Columns: block, ts_ms, iso_time, miner, builder, actual_total_eth (= what the proposer actually got: priority + coinbase), actual_priority_eth, actual_coinbase_eth, shadow_bid_eth, would_have_won, tx_count. Live tail: GET /v1/q/proposer-payment ($0.001).