Emailens
REST API

Authentication

Authenticate with the Emailens API using API keys or session cookies.

Pass your API key in the Authorization header:

curl -X POST https://emailens.dev/api/preview \
  -H "Authorization: Bearer ek_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"html": "..."}'

API keys start with ek_ and are tied to your account. Generate them from Dashboard > API Keys.

Key limits by plan

PlanMax API keys
Free0 (web app only)
Dev ($9/mo)1
Pro ($19/mo)10

When using the web app, authentication is handled via session cookies (Better Auth). This is automatic — no configuration needed.

The session cookie is set when you sign in via:

  • Email/password
  • Google OAuth
  • GitHub OAuth

Anonymous access

The API works without authentication, but with lower limits:

  • 30 requests/minute (vs 60 authenticated)
  • 3 previews/day (vs plan limits)
  • No saved previews
  • No API keys

REST API

Complete reference for the Emailens REST API — preview emails, manage API keys, and create share links.

Rate Limiting

Rate limits, daily quotas, and how to handle 429 responses.

On this page

API key (recommended)Key limits by planSession cookieAnonymous access