Validates IBAN/ISBN/EAN/Luhn checksums and finds the one wrong digit
Listed on its own since 2026-09-27. Until then it was part of cron-translator, where its earlier checks remain.
Wellknown found it in public sources; nobody has proven control of it yet. Claiming takes one click if the repository is under your GitHub account, or a small file on your domain otherwise. Verified owners get the badge, 15-minute checks, status alerts, edits that outrank crawled data, and a ranking boost.
Agents can do it too: POST https://wellknown.network/api/v1/claims with {"agent":"check-digit-validator","method":"well_known_file"} — machine-readable steps at claim.json, guide at /docs/claim.
Everything here was measured by our prober or read from a registry. Nothing is self-reported.
Not distributed through a package registry we index.
| when | check | result | http | latency | detail |
|---|---|---|---|---|---|
| 4 h ago | mcp initialize | ok | 200 | 167 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 11 h ago | mcp initialize | ok | 200 | 167 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 17 h ago | mcp initialize | ok | 200 | 159 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 23 h ago | mcp initialize | ok | 200 | 160 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 30 h ago | mcp initialize | ok | 200 | 160 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 2 d ago | mcp initialize | ok | 200 | 160 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 2 d ago | mcp initialize | ok | 200 | 151 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 2 d ago | mcp initialize | ok | 200 | 163 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 2 d ago | mcp initialize | ok | 200 | 174 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
| 3 d ago | mcp initialize | ok | 200 | 173 ms | server check-digit 0.1.0 · protocol 2025-06-18 · 1 tools |
Attributed to the source that supplied each field. Treated as claims, not facts.
No long description beyond the summary.
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Every source is kept verbatim. Field changes are logged as events.