Authentication

Docs index for AI agents: https://mailvalid.io/llms.txt. Every docs page is also available as Markdown: add .md to its URL.

Every MailValid API request needs an API key. Send it in the X-API-Key header.

Get your API key

1. Create an account. Sign up at mailvalid.io/register. You get 100 free credits.
2. Generate an API key. Go to Dashboard → API Keys and click "Create New Key".
3. Add the header to your requests. Include X-API-Key: mv_live_your_key_here in every API request.

Live keys start with mv_live_. Keep them server-side and never ship them in browser or mobile code.

Example request

curl -X POST https://mailvalid.io/api/v1/verify/single \
  -H "X-API-Key: mv_live_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"email": "test@example.com"}'

Bearer tokens

The MCP server also accepts the key as Authorization: Bearer mv_live_....

Keys for AI agents

An agent can self-register for an API key and hand the account to a human to claim. The flow is described in auth.md.

Errors

A missing, invalid or revoked key returns 401 Unauthorized. See Errors.