{"uid":"cap_NUDhrf9cofR8NCVDZns-N","slug":"is-port-21-open-012902e2","name":"is-port-21-open","description":"Is TCP port 21 (FTP) open on a host? Attempts a connection from Cloudflare's edge and reports open/closed/filtered with the connect time; Cloudflare-fronted hosts are reported as inconclusive because their edge answers for them. Exposure checks for FTP without running a scanner. $0.01 per check.","url":"https://ip.intel.rallylive.ca/ip/port/21?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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_N0sDmriV6sk7tIG0NWCGh","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 TCP port 21 (FTP) is open, closed, or filtered on a given host by attempting a connection from Cloudflare's edge network","exampleAgentPrompt":"Can you check if TCP port 21 (FTP) is open or closed on the host 203.0.113.45 — I want to know if it's exposed without me having to run a scanner myself.","exampleUseCases":[{"title":"FTP exposure audit on production server","prompt":"I need to know if FTP port 21 is open or exposed on our production server at api.mycompany.com — can you check from an external perspective?"},{"title":"Security sweep of customer-reported IP","prompt":"A customer flagged 198.51.100.22 as potentially running FTP. Can you probe port 21 on that IP and tell me if it's open, closed, or filtered?"},{"title":"Automated FTP risk check in onboarding","prompt":"Before we onboard this new vendor at 203.0.113.88, can you check if they have FTP port 21 open? I want to flag any insecure legacy protocols."}],"resultDescription":"Returns whether TCP port 21 is open, closed, or filtered on the target host, along with the connection time in milliseconds. If the host is behind Cloudflare's edge, the result is marked inconclusive because Cloudflare intercepts the connection on their behalf.","failureModes":["Host is Cloudflare-fronted — result returned as inconclusive because Cloudflare's edge answers the connection attempt","Invalid or unresolvable hostname — endpoint may return an error or timeout","Firewall silently drops packets — reported as 'filtered' rather than 'closed'","Network-level timeout if target is unreachable — may be reported as filtered","Payment not processed — call rejected with 402 status"],"whenToPreferThis":"Use this endpoint when you need a quick, external perspective on whether FTP (port 21) is exposed on a host without deploying your own scanner. It is ideal for one-off exposure checks, pre-onboarding vendor audits, or lightweight security sweeps. Prefer it over generic port scanners when you want a Cloudflare-edge vantage point and a pay-per-check model at $0.01 per call. Note that Cloudflare-fronted hosts will yield inconclusive results, so it is best suited for hosts with direct internet exposure.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-10T18:43:47.613Z","isFirstParty":false,"canonicalSlug":"is-port-21-open-012902e2"}