{"uid":"cap_q7CyldQn5-HzaaYNr5ZX6","slug":"canonical-url-invisible-character-flags-detector-57dc7a17","name":"Canonical URL Invisible Character Flags Detector","description":"Canonical URL declarations — Invisible character flags: Invisible character flags for Canonical URL declarations. One public HTTPS page or supplied HTML; static parsing, no JavaScript rendering, login or access bypass. Specialised preset in a shared 50-profile, 20-operation engine. 0.01 USDC includes one bounded invisible character flags result.","url":"https://market.datapackvibe.com/x402/assistant-bx-web-canonical-unicode?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","default":"","maxLength":2048},"html":{"type":"string","default":"<!doctype html><html><head></head><body><link rel=\"canonical\" href=\"https://www.iana.org/help/example-domains\" id=\"sample\"></body></html>","maxLength":100000},"term":{"type":"string","default":"product","maxLength":100,"minLength":1},"attribute":{"type":"string","default":"id","pattern":"^[a-zA-Z][a-zA-Z0-9:_-]{0,49}$","maxLength":50},"previous_texts":{"type":"array","items":{"type":"string","default":"","maxLength":1000},"default":["Older example"],"maxItems":200,"minItems":0},"attribute_value":{"type":"string","default":"sample","maxLength":200}}},"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_jS-wV7nfFwrrWUV1FOOoj","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":"Scans a web page or HTML snippet for invisible/unusual Unicode characters within canonical URL declarations and flags any anomalies found.","exampleAgentPrompt":"Check this page's canonical URL tag for any invisible or hidden Unicode characters — use the HTML I'm pasting here: <!doctype html><html><head><link rel=\"canonical\" href=\"https://example.com/page\" id=\"canonical-tag\"></head><body></body></html> and look at the element with id 'canonical-tag'.","exampleUseCases":[{"title":"SEO audit for hidden Unicode injection","prompt":"I want to audit my site's canonical tags — can you scan this HTML for invisible or zero-width characters hidden inside the canonical link element? Here's the HTML: <!doctype html><html><head><link rel=\"canonical\" href=\"https://mysite.com/products\" id=\"canonical-main\"></head><body></body></html> — check the element with id 'canonical-main'."},{"title":"Security check on competitor canonical tag","prompt":"Can you fetch https://www.competitor.com/landing-page and check if their canonical URL declaration contains any invisible Unicode characters or hidden flags that might indicate manipulation?"},{"title":"QA pipeline canonical tag validation","prompt":"Before we publish, check this page HTML for any invisible character anomalies inside the canonical tag — the attribute to inspect is 'href' on the element with id 'page-canonical': <!doctype html><html><head><link rel=\"canonical\" href=\"https://shop.mystore.com/shoes\" id=\"page-canonical\"></head><body></body></html>"}],"resultDescription":"Returns a bounded result flagging any invisible or unusual Unicode characters found within canonical URL declarations in the provided HTML or fetched page, including details about the flagged characters and their positions within the canonical element.","failureModes":["URL is unreachable or returns non-200 status — parsing falls back to empty or error result","HTML exceeds 100,000 character limit — input rejected","No canonical link element found in the document — empty flags result returned","JavaScript-rendered canonical tags not detected — only static HTML is parsed","Malformed HTML may cause incomplete parsing results"],"whenToPreferThis":"Choose this endpoint when you specifically need to detect invisible or non-printing Unicode characters embedded in HTML canonical URL declarations, such as for SEO integrity audits, security reviews of canonical tag manipulation, or QA pipelines validating page metadata before publication. It is not a general HTML parser or full SEO auditor — it is a specialized invisible-character detector scoped to canonical link elements.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-21T00:52:36.568Z","isFirstParty":false,"canonicalSlug":"canonical-url-invisible-character-flags-detector-57dc7a17"}