{"uid":"cap_Faf_2SMvH77o6C_F33cwc","slug":"web-page-json-field-change-monitor-sha-256-hash-watch-6102f4e0","name":"Web Page & JSON Field Change Monitor (SHA-256 Hash Watch)","description":"SHA-256 of a page or JSON body + change detection vs a baseline hash. Stateless monitoring. Add &json_path=a.b.0 to extract and watch a single JSON field (price, counter). ?url=https://example.com&baseline=<sha256>&json_path=bitcoin.usd","url":"https://pyfile-agent.taile3ff35.ts.net/data/watch","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":{}}}},"output":{"type":"object"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_akKvbArEov2oKvzO00YAX","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the SHA-256 hash of a URL's page or JSON body and compares it against a provided baseline hash to detect changes, with optional JSON path extraction for watching specific fields.","exampleAgentPrompt":"Check if the page at https://example.com has changed since I last looked — my saved baseline hash is abc123def456... — and also pull out just the bitcoin.usd field from the JSON to see its current value.","exampleUseCases":[{"title":"Crypto price change alert","prompt":"Watch https://api.coindesk.com/v1/bpi/currentprice.json and tell me if the bitcoin.usd value has changed from my baseline hash 9f86d081884c7d659a2feaa0c55ad015. Extract just that bitcoin.usd field for me."},{"title":"Product page tamper detection","prompt":"Has https://mystore.com/product/widget changed at all since yesterday? My baseline SHA-256 from last night is e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 — let me know if anything on the page is different."},{"title":"API counter monitoring","prompt":"I'm tracking a JSON endpoint at https://api.myapp.com/stats and want to know if the users.total counter has changed from my baseline hash d04b98f48e8f8bcc15c6ae5ac050801cd6dcfd428fb5f9e65c4e16e7807340fa — check it and pull out the users.total field."}],"resultDescription":"Returns the current SHA-256 hash of the fetched URL content (or extracted JSON field value), a boolean or status indicating whether it matches the provided baseline hash, and optionally the extracted value at the specified JSON path. The response is stateless — no history is stored server-side.","failureModes":["Target URL is unreachable or returns a non-200 status — hash cannot be computed","Invalid or malformed JSON path provided — field extraction fails","Baseline hash format is incorrect — comparison cannot be performed","Target URL returns dynamic content (ads, timestamps) causing false-positive change detection","URL requires authentication — fetch returns login page instead of expected content","Rate limiting or blocking by the target server during fetch"],"whenToPreferThis":"Choose this endpoint when you need lightweight, stateless change detection for a specific URL or JSON field without maintaining your own storage or polling infrastructure. It is ideal for agents that already hold a previous hash and want a one-shot comparison. Prefer this over full scraping pipelines when you only care whether content has changed (not what changed), and especially when you need to watch a single deeply nested JSON field like a price or counter via json_path extraction.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T13:05:21.628Z","isFirstParty":false}