About ContactLint
ContactLint is a small, one-person developer tool. It is built and run by John Alewine in Kansas City, Missouri, and operates as a trade name of Crypto Boutique LLC, a Missouri limited liability company. That is the name you will see on a card statement.
What it is
An HTTP API and a hosted MCP server that check email addresses (syntax, MX and A records, disposable domains, role addresses, typos) and phone numbers (parsing, line type, region, E.164 format) before you save them. It is meant for signup forms, AI agents that write to a CRM, and list cleanup.
What it is not
It never opens an SMTP connection, so it cannot confirm that a specific mailbox exists or detect catch-all domains. If you need that, a mailbox verifier is the right tool; our comparison says which ones and what they cost.
How it is built
- Runs on Cloudflare Workers with a D1 database; DNS lookups go through Cloudflare DNS-over-HTTPS.
- Phone parsing uses libphonenumber-js (MIT). The disposable domain list comes from the open disposable-email-domains project (CC0 1.0), refreshed from upstream.
- Payments run on Stripe. Checked addresses and numbers are never written to the database; see the privacy policy.
- Listed in the official MCP Registry as
com.contactlint/contactlint, on Glama, and on GitHub.
Where things stand
Launched October 12, 2026. Every change that affects what you can see or call is on the changelog; live component checks are on the status page.
Contact
Email support@contactlint.com for support, refunds (unused credits within 14 days) and data requests. One person reads it.