eusend
Getting Started

Authentication

Authenticate with API keys in the Authorization header.

All API requests must include an API key in the Authorization header.

Authorization: Bearer eu_live_xxxxxxxxxxxx

Key types

ParameterTypeDescription
eu_live_...stringProduction key. Emails are actually sent.
eu_test_...stringTest key. Emails are queued but not delivered. Use for development and CI.

Test mode keys replay the full event lifecycle — and fire the same webhooks — as live keys, without delivering to the recipient's inbox. By default a send simulates email.sentemail.deliveredemail.openedemail.clicked (opens and clicks follow the message's tracking settings). To simulate failures, send to bounced@… for a bounce or complained@… for a complaint. Ideal for integration testing.

Creating API keys

API keys are managed in the API Keys section of the dashboard. You can create multiple keys and revoke them individually. Free plan allows 1 key; paid plans allow unlimited keys.