emulate

Resend

Resend email API emulation with email sending, domain management, API keys, audiences, contacts, and a local inbox for captured messages.

Emails

  • POST /emails — send single email
  • POST /emails/batch — send up to 100 emails
  • GET /emails — list sent emails
  • GET /emails/:id — get email
  • POST /emails/:id/cancel — cancel scheduled email

Idempotency

POST /emails and POST /emails/batch accept the case-insensitive Idempotency-Key header. Keys must be 1 to 256 characters and are retained for 24 hours. Repeating a request with the same key and validated payload returns the original response without creating another email or dispatching duplicate webhooks. Reusing a key with a different payload or endpoint returns 409 invalid_idempotent_request. Invalid key lengths return 400 invalid_idempotency_key. Requests without the header keep the normal non-idempotent behavior.

Domains

  • POST /domains — create domain
  • GET /domains — list domains
  • GET /domains/:id — get domain
  • DELETE /domains/:id — remove domain
  • POST /domains/:id/verify — trigger domain verification

API Keys

  • POST /api-keys — create API key
  • GET /api-keys — list API keys
  • DELETE /api-keys/:id — delete API key

Audiences & Contacts

  • POST /audiences — create audience
  • GET /audiences — list audiences
  • DELETE /audiences/:id — delete audience
  • POST /audiences/:audience_id/contacts — add contact
  • GET /audiences/:audience_id/contacts — list contacts
  • DELETE /audiences/:audience_id/contacts/:id — delete contact

Inbox

  • GET /inbox — list captured emails
  • GET /inbox/:id — view captured email