{"status":"ok","rate_limit":{"free_calls_remaining_today":245,"paid_via_x402":false},"apiId":"bitcoin-mempool-backlog","name":"Bitcoin Mempool Unconfirmed Transactions & Congestion Monitor","category":"Finance & Markets","subcategory":"3. Blockchain & On-Chain Oracles","cached":false,"stale_fallback":false,"data_freshness":"live","cache_age_seconds":0,"latency_ms":36,"provenance_and_trust":{"verified_at_utc":"2026-10-27T19:59:50.345Z","primary_authority":"Mempool.space Backlog API","source_url":"https://mempool.space/api/mempool","fallback_source_url":null,"license_type":"MIT Open Source Blockchain Data","terms_url":"https://mempool.space/docs/api","commercial_use_allowed":true,"trust_tier":"public_third_party_api"},"data":{"unconfirmed_tx_count":54119,"vsize_bytes":21495150,"vsize_megabytes":21.5,"total_fee_btc":0.0685},"_agent_hint":"Agent Data Hub: ask anything via GET /api/v1/ask?q=..., whole tasks via /api/v1/bundles, up to 10 calls via POST /api/v1/batch. Add compact=1 or fields=a,b to save tokens. Docs: /llms.txt"}