{"uid":"cap_9fWikzUYUTQ24pBKDWYzm","slug":"sentinel-tcp-port-reachability-checker-36f7fa4e","name":"Sentinel TCP Port Reachability Checker","description":"TCP port reachability and connect latency","url":"https://sentinel.rootstuff.io/x402/port","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"host":{"type":"string","description":"Hostname or public IP."},"port":{"type":"integer","description":"1 to 65535."}}},"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_t4iTAB3re7vPhQ-dtq4Ux","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 specific TCP port on a host is reachable and measures the connection latency","exampleAgentPrompt":"Can you check if TCP port 5432 is reachable on db.mycompany.com and tell me how long the connection takes?","exampleUseCases":[{"title":"Verify production database port exposure","prompt":"Check whether port 5432 is open and reachable on db.prod.mycompany.com — I want to make sure it's not accidentally exposed to the internet."},{"title":"Diagnose web server connectivity issue","prompt":"My users are saying they can't reach my site — can you test if TCP port 443 is actually reachable on api.myapp.io and what the connect latency is?"},{"title":"Confirm firewall rule blocked a port","prompt":"I just updated my firewall rules to block port 3306 on 198.51.100.42 — can you verify that the port is now unreachable from the outside?"}],"resultDescription":"Returns whether the TCP port is reachable (open/closed/timeout) and the measured connect latency in milliseconds for the given host and port combination.","failureModes":["Host not found or unresolvable DNS — returns error indicating hostname could not be resolved","Connection timeout — port may be firewalled or host unresponsive, returned as timeout status","Invalid port number outside 1-65535 range — returns validation error","Host is a private/internal IP that is not publicly routable — probe may fail or return unreachable","Rate limiting or payment failure — returns 402 or rate-limit error"],"whenToPreferThis":"Use this endpoint when you need a quick, cheap TCP-level connectivity check against a specific host and port — ideal for verifying firewall rules, diagnosing service outages, or confirming a port is open before attempting a connection. Prefer this over full HTTP probing endpoints when you only need raw TCP reachability and latency, not HTTP response content or headers.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:33:56.190Z","isFirstParty":false}