{"uid":"cap_txPlQGjkx59SyVNhuegbf","slug":"is-port-502-open-2159534d","name":"is-port-502-open","description":"Is TCP port 502 (Modbus) 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 Modbus without running a scanner. $0.01 per check.","url":"https://ip.intel.rallylive.ca/ip/port/502?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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_GatRhjLYnKwbajN26SYJC","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 502 (Modbus) 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 502 (Modbus) is open or exposed on the host 192.168.1.100 — I want to know if it's reachable from the internet without running a local scanner.","exampleUseCases":[{"title":"ICS device internet exposure audit","prompt":"I need to check whether port 502 is publicly reachable on our SCADA gateway at scada.mycompany.com — we want to make sure our Modbus interface isn't accidentally exposed to the internet."},{"title":"Security sweep of a PLC IP","prompt":"Can you tell me if TCP port 502 is open, closed, or filtered on the IP 203.0.113.45? We're auditing an industrial site for unintended Modbus exposure."},{"title":"Pre-deployment Modbus firewall verification","prompt":"Before we go live, check that port 502 is closed on our new edge device at plc-edge.factory.io — I need to confirm the firewall rules are blocking Modbus from the outside."}],"resultDescription":"Returns whether TCP port 502 is open, closed, or filtered on the target host, along with the connection time in milliseconds. If the host is Cloudflare-fronted, the result is marked as inconclusive because Cloudflare's edge intercepts the connection on behalf of the origin.","failureModes":["Host is Cloudflare-fronted — result returned as 'inconclusive' because Cloudflare's edge answers the connection attempt","Host or IP unreachable — may return filtered or timeout","Invalid hostname or IP format in query — likely 4xx error","Connection attempt blocked by intermediate firewall — reported as filtered rather than closed","Service temporary unavailability — upstream probe error"],"whenToPreferThis":"Use this endpoint when you need a quick, passive check of whether Modbus (TCP port 502) is exposed on a host without running a local port scanner or installing any tooling. Ideal for security audits, compliance checks, or pre-deployment verification of OT/ICS devices. Prefer this over general-purpose port scanners when you want a lightweight, pay-per-check approach from Cloudflare's edge perspective with no setup overhead.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T18:40:21.875Z","isFirstParty":false,"canonicalSlug":"is-port-502-open-2159534d"}