{"uid":"cap_neeS-RgF8Y3zPWxykcKjP","slug":"how-is-domain-blacklist-check-f88a8d51","name":"how.is Domain Blacklist Check","description":"Whether the addresses behind a domain appear on spam and abuse blocklists.","url":"https://how.is/v1/domain/blacklist?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"domain":{"type":"string","maxLength":253,"description":"A bare domain name, e.g. example.com"}}},"responseSchema":{"type":"json","example":{"data":{"_shape":"data.data.ipResults[]: target, isListed, listingCount, totalChecked."},"result":"Blacklist status for the requested subject","receipt":{"rail":"x402","tool":"blacklist","charge_usd":0.005,"settlement_tx":"0x…"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_7xof-VE4SFPzMjCjVLaNM","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether the IP addresses behind a domain appear on spam and abuse blocklists.","exampleAgentPrompt":"Can you check whether suspiciousdomain.com is listed on any spam or abuse blocklists — specifically whether its IP addresses are flagged?","exampleUseCases":[{"title":"Email deliverability pre-send check","prompt":"Before we send our newsletter campaign, can you check if our sending domain mailouts.acme.com is showing up on any spam or abuse blocklists?"},{"title":"Vetting a third-party vendor domain","prompt":"We're about to integrate with a partner at partnerhub.io — can you check if their domain's IPs are blacklisted on any abuse lists before we proceed?"},{"title":"Investigating suspicious inbound email","prompt":"I got a sketchy email from someone at bargainpharmacy.ru — can you check if that domain is on any spam or abuse blocklists?"}],"resultDescription":"Returns a JSON object with per-IP results for the queried domain, including whether each IP is listed on any blocklist, how many lists it appears on, and how many total blocklists were checked. Also includes a receipt with payment metadata.","failureModes":["Invalid or malformed domain name returns an error","Domain with no resolvable IPs may return empty or null IP results","Rate limiting or payment failure may prevent the call from completing","Domain may have IPs not yet indexed by blocklist providers, leading to incomplete results"],"whenToPreferThis":"Use this endpoint when you need to check whether a specific domain's underlying IP addresses are flagged on known spam and abuse blocklists. Ideal for email deliverability verification, security vetting of third-party domains, or investigating suspicious senders. Prefer this over generic WHOIS or DNS lookups when the specific question is about blacklist/blocklist reputation rather than ownership or DNS records.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:39:52.806Z","isFirstParty":false,"canonicalSlug":"how-is-domain-blacklist-check-f88a8d51"}