email qualification api

classify any email as b2b, personal, education, government, or disposable

// what it does

send an email address, get back a verdict with confidence score. handles batch requests too. built for lead qualification pipelines.

// verdicts

private_b2b personal education government disposable unknown

// endpoints

POST/v1/qualify-email

classify a single email address

POST/v1/qualify-email/batch

classify up to 50 emails at once

GET/health

health check + redis status

GET/docs

swagger ui documentation

// example request (ofc it's not a real endpoint, I keep it for me)

curl -X POST http://localhost:3000/v1/qualify-email \
  -H "Content-Type: application/json" \
  -H "X-API-Key: your_api_key" \
  -d '{"email": "ceo@acmecorp.com"}'

// example response

{
  "email": "ceo@acmecorp.com",
  "verdict": "private_b2b",
  "confidence": 0.85,
  "is_business_email": true,
  "is_private_b2b": true,
  "domain": "acmecorp.com",
  "flags": [],
  "checks": {
    "syntax_valid": true,
    "has_mx_record": true,
    "is_disposable": false,
    "is_free_provider": false
  }
}

// stack

typescript fastify redis vitest zod psl

// features

1500+ domain lists (personal, disposable, edu, gov)
mx record validation with redis caching
redis-backed rate limiting with in-memory fallback
api key authentication
swagger ui documentation
batch endpoint (up to 50 emails)
171 passing tests