{"uid":"cap_VGglXcltiB5sv31CPyj7-","slug":"lookproof-ip-in-cidr-containment-check-9165aa10","name":"Lookproof IP-in-CIDR Containment Check","description":"Check SPF, DMARC, DKIM, MTA-STS, DNSSEC and more, with results that explain what was found and why. Free browser checks and a pay-per-request API with x402.","url":"https://api.lookproof.dev/v1/ip/contains?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"ip":{"type":"string","title":"Ip","maxLength":64,"minLength":2},"cidrs":{"type":"array","items":{"type":"string","maxLength":64,"minLength":2},"title":"Cidrs","maxItems":100,"minItems":1}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Mq7E8BLiYBzJavDnpyv_1","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether a single IPv4 or IPv6 address falls within any of up to 100 CIDR blocks, returning per-block match results and the list of matching blocks.","exampleAgentPrompt":"Check whether 192.0.2.10 is contained in any of these CIDR blocks: 192.0.2.0/24, 10.0.0.0/8, and 172.16.0.0/12 — and tell me which ones match.","exampleUseCases":[{"title":"Allow-list gating for incoming requests","prompt":"I need to know if the IP 203.0.113.45 is in any of my allow-listed ranges — check it against 203.0.113.0/24, 198.51.100.0/22, and 10.0.0.0/8 and tell me which ones match."},{"title":"SPF ip4 term validation","prompt":"Can you verify whether the sending IP 198.51.100.77 is covered by any of these SPF ip4 terms: 198.51.100.0/25, 198.51.100.128/25, and 192.0.2.0/24?"},{"title":"Cloud provider IP range attribution","prompt":"Tell me which of AWS's CIDR blocks — 52.94.0.0/22, 52.119.224.0/20, and 54.239.0.0/17 — contain the IPv4 address 52.119.225.10."}],"resultDescription":"Returns a boolean result for each submitted CIDR block indicating whether it contains the input IP address, plus a filtered list of only the blocks that matched. Blocks of the opposite IP version (e.g. IPv4 CIDRs when the input is IPv6) are automatically treated as non-matching.","failureModes":["Invalid IP address format returns a validation error","Malformed CIDR notation in the list causes an error response","Submitting more than 100 CIDRs exceeds the maxItems limit and is rejected","Mixing an IPv6 input with IPv4 CIDRs yields no matches (by design, not an error)","Empty CIDR array rejected due to minItems constraint"],"whenToPreferThis":"Use this endpoint when an agent needs to perform offline, server-side IP containment checks against multiple CIDR ranges in a single call — especially for allow/deny list enforcement, SPF record validation, or cloud provider IP attribution. Prefer it over client-side logic when auditable, consistent, and multi-block batch evaluation is needed without managing networking libraries.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:39:32.977Z","isFirstParty":false,"canonicalSlug":"lookproof-ip-in-cidr-containment-check-9165aa10"}