Use the K2Mailer REST API

Enable access

1. 1

   Open Settings → API and enable the API for the account.

2. 2

   Copy the displayed API key and base URL ending in /api/v1.

3. 3

   Send the token in the Authorization header as Bearer YOUR_API_TOKEN.

4. 4

   Use the complete endpoint reference at k2mailer.com/help/api for request fields, examples, responses, and rate limits.

5. 5

   Regenerate the token immediately if it is exposed. The old token should no longer be used.

Available resource groups

• Read the authenticated user and add client records.
• Create, read, update, and delete groups.
• Create, read, update, and delete lists and custom fields.
• List, create, update, remove, and delete contacts.
• Create, read, update, and delete saved broadcast content. These endpoints save content but do not send or schedule a campaign.

Responses and pagination

• Most resource responses use a status and response JSON envelope. GET /user returns the user object directly.
• Some business-rule failures can use HTTP 200 with status set to Error, so inspect both the HTTP code and JSON status.
• Authentication, disabled API access, validation, and rate limits use HTTP 401, 403, 422, and 429.
• Collection endpoints use start_from as a zero-based offset and return up to 500 records. They do not accept a limit parameter.