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1633–1656 of 2047 APIs

GST API

Validate and decode Indian GSTINs (the 15-character Goods & Services Tax Identification Number) instantly and entirely offline. The validate endpoint checks the structure and recomputes the official GSTIN check digit — the base-36 weighted algorithm the GSTN itself uses — and confirms the embedded state code is real, returning a clear valid/invalid verdict with the specific reasons a number fails. The decode endpoint breaks a GSTIN into its parts: the GST state/UT code and its name, the embedded 10-character PAN, the PAN holder type (company, individual/proprietor, firm/LLP, HUF, trust, government and more, read from the PAN's 4th letter), the entity registration number, the default 'Z' slot and the check digit. A states endpoint returns the full GST state-code reference for building dropdowns and lookups. Everything is pure computation — no network call, no key, no cache — so it is fast and private, ideal for checkout and onboarding forms, invoicing and e-invoice/e-way-bill pipelines, vendor master data cleansing and bulk validation. A structural GSTIN validator and decoder — distinct from EU VAT-number validation (vat), IBAN bank-account validation (iban) and card-number checks (creditcard). Note: this verifies the number's structure and check digit, not whether it is actively registered in the GSTN portal. No upstream key, no cache.

#gst #gstin #india
P by PremiumApi
Uptime
100.0%
Latency
171ms
Subs
3,943
Server verified 8 probes/24h

api.oanor.com/gst-api

free · from €6.18/mo

ads.txt API

Fetch and evaluate any publisher's ads.txt / app-ads.txt — the IAB authorized-digital-sellers standard. Pass a domain and the check endpoint fetches its ads.txt server-side, then returns every seller record parsed into its fields — advertising system, the publisher's seller/account id, the DIRECT or RESELLER relationship and the optional certification-authority id (TAG-ID) — alongside counts (direct, reseller, distinct ad systems) and the declared variables OWNERDOMAIN, MANAGERDOMAIN, CONTACT and SUBDOMAINS. The verify endpoint answers the one question programmatic-advertising integrations actually ask: is this advertising system, with this publisher id, authorized to sell this domain's inventory? — returning an authorized boolean and the matching records. A missing file is reported as found:false (not an error), and soft-404 HTML pages are detected and rejected so you never parse a "page not found" as records. The request is made server-side and private or internal targets are refused (SSRF-guarded). Built for ad-tech supply-chain verification, SSP/DSP onboarding checks, anti-fraud and inventory audits. An ads.txt seller-authorization checker — distinct from the security-contact file reader (securitytxt), the robots.txt crawlability evaluator (robots) and the sitemap parser (sitemap). No upstream key, no cache.

#ads-txt #adtech #advertising
P by PremiumApi
Uptime
100.0%
Latency
253ms
Subs
4,867
Server verified 6 probes/24h

api.oanor.com/adstxt-api

free · from €6.15/mo