{"uid":"cap_UBQeqwM_spWWXxwJjnfgL","slug":"forest-gas-station-service-state-change-detection-f7e0ff08","name":"Forest Gas Station – Service State Change Detection","description":"Cheap watchdog: material service state changed since prior canonical hash? Base mainnet USDC","url":"https://http--forest-gas-station-mainnet--lcjl27p8lmjs.code.run/service/changed?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"status_url":{"type":"string","description":"Public status url value used to scope this lookup."},"previous_hash":{"type":["string","null"],"maxLength":128,"description":"Earlier result hash used to detect a material change."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_DNWYi7vuymtFlVAwFoJHS","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether a remote service's current state has materially changed since a previously recorded canonical hash, acting as a cheap watchdog.","exampleAgentPrompt":"Check if the service at https://api.example.com/status has changed since the last time I polled it — the previous hash was a3f7b2c1d4e5 — and tell me if anything material is different now.","exampleUseCases":[{"title":"Pre-deployment service readiness gate","prompt":"Before I trigger the deployment pipeline, check if the service at https://infra.mycompany.com/health has materially changed since our last baseline hash b9d3a7f2c1e8 — I only want to proceed if nothing has shifted."},{"title":"Scheduled API status watchdog","prompt":"Every 15 minutes I want you to check whether https://partner-api.vendor.com/status has changed from hash 4f2e9c7a1b3d and alert me the moment something looks different."},{"title":"Baseline drift check after incident","prompt":"After that incident earlier, verify whether https://payments.myapp.com/service-status has diverged from the canonical hash we captured at 3pm — previous hash was 7c1d4b9e2a6f — so I know if the state has been restored or is still different."}],"resultDescription":"A response indicating whether the service at the given URL has materially changed since the provided previous hash, along with the current canonical hash of the service state for future comparisons. If no previous hash is supplied, the current hash is returned as a baseline.","failureModes":["status_url is unreachable or returns a non-2xx response, causing the probe to fail","previous_hash format exceeds 128 characters, rejected by schema validation","service returns inconsistent or non-deterministic content making hash comparison unreliable","network timeout when probing the target URL","malformed status_url causes request failure"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, cheap ($0.001) way to detect whether a service's state has materially changed without parsing or deeply analyzing the full response — ideal for polling loops, pre-action checks, and drift detection. Prefer it over full scraping or status-page parsers when you only need a boolean changed/unchanged signal plus a hash for future comparisons.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T00:48:47.400Z","isFirstParty":false,"canonicalSlug":"forest-gas-station-service-state-change-detection-f7e0ff08"}