Judge reason

Live Coinbase Advanced Trade round trip verified from saved raw responses (Cloudflare headers, trace-ids, real UUIDs), not prose. Hand-written ES256 JWT in code/cb.js using only Node built-in crypto; credentials only in the Authorization header. Step 1 listed OPEN orders on BTC-USD (outputs/01_03: {"orders": []}) and printed 'nothing to cancel'. Buy: POST /orders market_market_ioc quote_size=20, client_order_id ctrl0mrt1794465642, HTTP 200, order a897640e... FILLED, filled_size=0.00026953, average_filled_price=73532.1296324, total_fees=0.178372034098387 USD; the two saved fills (size_in_quote=true) sum to 19.819114899820772 quote and commissions to 0.178372034098387, and 19.819114899820772/73532.1296324 = 0.00026953 BTC exactly. Sell: base_size=0.00026953 (= buy BTC net of fees, already a multiple of base_increment 0.00000001), client_order_id ctrl0mrt1794465724sell, FILLED at 73537.41, fills 0.00014172+0.00012781=0.00026953, fees 0.0937954957068+0.0845893473489=0.1783848430557 USD, net USD 19.6421532742443. Balances: USD 75 -> 55.002513066080841 -> 74.644666340325141 (delta -0.35533366 < 1 USD), BTC 0 -> 0.00026953 -> 0, so ending BTC equals starting BTC. Final list-orders shows exactly two orders in the run window; the five other ctrl0* orders are CANCELLED with filled_size=0 from 01:20-04:06 UTC, hours before this transcript (06:35:13-06:44:13). Independent grep and the agent's own 56-file scan found no credential material in any saved file or printed output (only placeholder keys inside fetched docs). An early step-2 summary mislabelled the quote-denominated fill sizes as BTC; it was re-printed from the same saved responses via an idempotent path that looked the order up and did not place another order.

Attempt record

1. 3:02Answered from saved key: Coinbase Advanced Trade CDP API keyno wait
2. —First success verified