{"uid":"cap_rN21Y4AxxGmSUP6uTHpr8","slug":"hostkarma-black-dnsbl-lookup-98e21e42","name":"HostKarma Black DNSBL Lookup","description":"Is this IPv4 address listed on hostkarma black (hostkarma.junkemailfilter.com)? Performs the DNSBL query (reversed octets under hostkarma.junkemailfilter.com, via Cloudflare DoH) and returns listed yes/no with the return codes and, where the list publishes one, the reason text. One list, one precise answer. $0.01 per lookup.","url":"https://ip.intel.rallylive.ca/ip/blacklist/hostkarma-black?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_1kXhILdWjb_e3wEWczPTr","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether a given IPv4 address is listed on the HostKarma Black DNSBL (hostkarma.junkemailfilter.com) and returns listed status, return codes, and reason text.","exampleAgentPrompt":"Can you check if the IP address 203.0.113.47 is listed on the HostKarma Black spam blacklist and tell me whether it's flagged and why?","exampleUseCases":[{"title":"Pre-send email deliverability check","prompt":"Before we send our next campaign, check if our mail server IP 198.51.100.22 is listed on HostKarma Black — I want to know if it's blacklisted and what the reason is."},{"title":"Inbound spam filter triage","prompt":"We're getting suspicious emails from 203.0.113.85 — can you check if that IP is on the HostKarma Black DNSBL list so I know if it's a known spam source?"},{"title":"New server reputation audit","prompt":"I just spun up a new VPS at 192.0.2.10 to use as a mail relay — can you verify whether it's listed on HostKarma Black before I start sending?"}],"resultDescription":"Returns whether the IPv4 address is listed on the HostKarma Black DNSBL, the DNS return codes from the query, and, where available, the human-readable reason text explaining why the address is listed.","failureModes":["Invalid IPv4 address format returns an error","DNS resolution failure via Cloudflare DoH returns a lookup error","IP not listed returns a negative result with no reason text","Network timeout from Cloudflare DoH results in an error response"],"whenToPreferThis":"Choose this endpoint when you need a precise, single-list check against the HostKarma Black DNSBL specifically — ideal when you want authoritative HostKarma listing status with reason codes rather than a multi-list aggregated score. Prefer this over generic multi-DNSBL tools when HostKarma is a required check for your email filtering or IP reputation pipeline.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-13T00:41:29.522Z","isFirstParty":false,"canonicalSlug":"hostkarma-black-dnsbl-lookup-98e21e42"}