{"uid":"cap_nFnOoQjDy3d_yCWDp9AbT","slug":"is-port-137-open-a239103f","name":"is-port-137-open","description":"Is TCP port 137 (NetBIOS-NS) 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 NetBIOS-NS without running a scanner. $0.01 per check.","url":"https://ip.intel.rallylive.ca/ip/port/137?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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_0RlxfUFxKnmnq9FYN-lG2","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 137 (NetBIOS-NS) is open, closed, or filtered on a given host, returning the connection result and connect time from Cloudflare's edge.","exampleAgentPrompt":"Can you check whether TCP port 137 (NetBIOS-NS) is open or closed on 203.0.113.45 — I want to know if NetBIOS name service is exposed without running a scanner?","exampleUseCases":[{"title":"NetBIOS exposure audit on server","prompt":"I need to know if port 137 is open or filtered on 198.51.100.12 — is NetBIOS-NS accessible from the outside?"},{"title":"Security hardening verification","prompt":"We just hardened our server at example-corp.com and blocked NetBIOS. Can you confirm that TCP port 137 is now closed or filtered?"},{"title":"Pre-deployment network check","prompt":"Before we go live with 203.0.113.88, can you check whether port 137 is exposed? We definitely don't want NetBIOS-NS reachable from the internet."}],"resultDescription":"Returns whether TCP port 137 is open, closed, or filtered on the target host as seen from Cloudflare's edge, along with the TCP connect time in milliseconds. If the host is Cloudflare-fronted, the result is marked inconclusive because Cloudflare's edge answers on behalf of the origin.","failureModes":["Cloudflare-fronted hosts return 'inconclusive' because Cloudflare's edge intercepts the connection","Filtered ports may time out and take longer to return a result","Invalid or unresolvable hostnames may result in an error response","The check reflects reachability from Cloudflare's edge, not the broader internet — results may differ from other vantage points"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, agentless check of NetBIOS-NS (port 137) exposure on a host without deploying a network scanner. It is ideal for security audits, compliance checks, or pre/post-hardening verification where a fast, remote probe from a well-known edge network (Cloudflare) is acceptable. Prefer alternatives if you need scanning from multiple vantage points, UDP port checks, or scanning at scale (consider bulk endpoints if available).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T18:45:11.544Z","isFirstParty":false,"canonicalSlug":"is-port-137-open-a239103f"}