DEBYKO provides read-only access to crypto derivatives market data across venues. Explore venues and instruments, retrieve current snapshots, as-of history and completed candles, and screen instruments with DQL. The server also exposes the signed-in account's plan and Agent rule state, and a Merkle proof for a stored historical row. Results include provenance, freshness and gaps as returned by the DEBYKO API. Access follows the signed-in account's plan.