Check Digit Validator

com.gumballtools/check-digit · v0.1.0 · other

Check Digit Validator is healthy: it completed an MCP handshake in 4071 ms and exposes 1 tools. It scores 60/100.

Validates IBAN/ISBN/EAN/Luhn checksums and finds the one wrong digit

Endpoint: https://check-digit.gumballtools.com/api/mcp (streamable-http)

Repository · Website · JSON · Add to my inventory

Score 60/100

health	17 / 25
authEase	15 / 15
toolQuality	15 / 15
maintenance	5 / 15
adoption	0 / 10
usage	0 / 10
security	8 / 10

Scoring v0.3, computed 2026-10-15T08:40:34.457Z.

GitHub signals are off for everyone: maintenance uses registry dates (half credit)
Repo shared by 16 servers: stars credited once to the canonical server

Health history

Checked (UTC)	Status	Latency	Error
2026-10-14T19:45:44.370Z	Healthy	4071

Tools (1)

run Validate the check digit(s) on an IBAN, ISBN-10, ISBN-13, EAN-13, UPC-A, or Luhn-checked card number, and when it fails, try to say which digit is wrong. Use this instead of computing the checksum yourself. Mod-97 arithmetic on a rearranged 15-34 character IBAN, or a weighted sum mod 10/11 over 10-