{"uid":"cap_VS5nXj8q9bLmvpA9TEslc","slug":"basebuilder-trading-mempool-pending-transactions-1f5451da","name":"BaseBuilder Trading Mempool Pending Transactions","description":"BaseBuilder Trading API hub - 20 paid endpoints","url":"https://bb-trading-gold.vercel.app/api/mempool/pending?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":null,"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.188704","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.188704/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.188704","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.188704","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_yimdU2V2LoqrfD9tAZUtj","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.188704","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Retrieves or queries pending transactions currently in the blockchain mempool","exampleAgentPrompt":"Show me the current pending transactions in the Base mempool — I want to see any large unconfirmed swaps or trades waiting to be mined right now.","exampleUseCases":[{"title":"Detect front-running opportunities in mempool","prompt":"Check the Base mempool right now and show me any large pending swaps that haven't been confirmed yet — I want to spot any front-running opportunities before the next block gets mined."},{"title":"Confirm my transaction is pending","prompt":"I just submitted a transaction on Base and I'm not sure if it went through — can you check the mempool to see if my transaction is still pending and hasn't been confirmed yet?"},{"title":"Monitor mempool congestion for gas timing","prompt":"Pull the current mempool activity on Base for me — I want to see how many unconfirmed transactions are queued up and what gas prices people are using so I can time my next trade better."}],"resultDescription":"A list of pending transactions currently sitting in the mempool, including transaction hashes, sender/receiver addresses, gas prices, values, and transaction data for trades or transfers not yet confirmed on-chain.","failureModes":["No pending transactions found — empty mempool response","Payment of 0.188704 USDC not received — 402 Payment Required","Invalid or malformed request body — 400 Bad Request","Mempool data temporarily unavailable — 503 Service Unavailable","Rate limit exceeded — 429 Too Many Requests","Authentication or payment verification failure"],"whenToPreferThis":"Use this endpoint when you need real-time visibility into unconfirmed transactions on the Base network, particularly for trading bots, MEV strategies, front-running detection, or monitoring large pending swaps before block confirmation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-23T01:30:40.683Z","isFirstParty":false,"canonicalSlug":"basebuilder-trading-mempool-pending-transactions-1f5451da"}