List top-level keys from JSON-LD or JSON objects the caller already holds — call when listing keys from JSON-LD the caller already holds. Use on text/URLs the agent already holds—adjacent to high-volume extract demand, never advertised as general web or X search. Returns deterministic machine-readable JSON for $0.003 USDC via x402 on Base. Execution is first-party, local-only, stateless, and memory-only with no paid upstream, no input retention, and no claim of live chain tip, web search, or media generation. Results are advisory; the caller owns authorization and production controls.