Send a contact to Mailbo with the API

Once you have an API key, you can add or update contacts from your own code — useful for syncing signups from a custom app or backend.

The available endpoints

All API calls live under /api/v1/. The main ones:

• /api/v1/me — your workspace info (good for testing your key).
• /api/v1/contacts — create / update contacts.
• /api/v1/tags — manage tags.
• /api/v1/lists — manage lists.
• /api/v1/events — record events.
• /api/v1/sequences and /api/v1/sequences/:id/enroll — enroll a contact in a sequence.
• /api/v1/unsubscribe — unsubscribe a contact.

Example: add a contact

Send a POST to the contacts endpoint with your key as a Bearer token and the contact's details as JSON:

curl -X POST https://mailbo.io/api/v1/contacts \
  -H "Authorization: Bearer mb_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "ada@example.com",
    "first_name": "Ada",
    "tags": ["from-api"]
  }'

Mailbo creates the contact, or updates it if the email already exists (it de-duplicates by email — no duplicates).

Notes

• Custom field values go under the contact's attributes using each field's key (see custom fields).
• If double opt-in is on, API-created contacts are added directly unless you opt them into confirmation.
• Test against /api/v1/me first to confirm your key and auth header are correct.

Next: Set up an inbound webhook