Migrate from Brevo to Unitpost

Before you start

• A Brevo API key (xkeysib-…) from Settings → SMTP & API. Keys created with the MCP option work too.
• If Brevo blocks unknown IPs for API keys (Security → Authorised IPs), choose Deactivate for API keys before connecting, or Brevo rejects even a valid key.
• A Unitpost API key with emails:send, created in API keys.
• A second Unitpost key for the migration steps, with templates:write and webhooks:manage, saved as UNITPOST_MIGRATION_KEY. Keep it out of your app and revoke it once the move is done.
• Access to your DNS host.
• If you text contacts: SMS on Unitpost is on paid plans only, and marketing texts need consent recorded per contact.

The cut-over plan

Brevo keeps sending until the last step, so there is no gap in delivery.

1. 1

   Run the Migration Assistant

   Paste the key in Settings → Migration. Suppressions are written before contacts, so blocked and blocklisted addresses land unsubscribed. Check the domains line in the preview: if Brevo's domains API is not enabled for your account, add the domains by hand in step 2.

2. 2

   Verify your domains next to Brevo

   Open Domains (add any the importer could not read) and publish the records shown: MX and SPF on unitpost.<your domain> and a DKIM TXT under _domainkey. They do not replace Brevo's records, so both providers stay authenticated. Keep your single _dmarc record.

3. 3

   Rewrite template variables and publish

   {{ params.order_id }} becomes {{order_id}}, filled from template.variables. {{ contact.FIRSTNAME }} and {{ contact.LASTNAME }} become {{first_name}} and {{last_name}}, which fill from the recipient's contact. Set receipts to transactional (imports land as marketing, which adds a footer) and publish with PATCH /api/v1/email/templates/{id}.

4. 4

   Switch the API call

   sender becomes a from string, to takes addresses, htmlContent becomes html, and templateId with params becomes template: { id, variables }. The api-key header becomes Authorization: Bearer, and sends accept an Idempotency-Key.

   send.ts

   // Before: Brevo
   await fetch("https://api.brevo.com/v3/smtp/email", {
     method: "POST",
     headers: { "api-key": process.env.BREVO_API_KEY, "content-type": "application/json" },
     body: JSON.stringify({
       sender: { name: "Acme", email: "hi@acme.com" },
       to: [{ email: "user@example.com" }],
       templateId: 8,
       params: { order_id: "A-1009" },
     }),
   });
   
   // After: Unitpost
   import { Unitpost } from "unitpost";
   const unitpost = new Unitpost(process.env.UNITPOST_API_KEY);
   const { data, error } = await unitpost.email.send({
     from: "Acme <hi@acme.com>",
     to: "user@example.com",
     template: { id: "tmpl_123", variables: { order_id: "A-1009" } },
   });

5. 5

   Re-key and enable webhooks

   Brevo protects webhooks with credentials in the URL, a bearer token or an IP allowlist; Unitpost signs each body with a whsec_ secret in the svix headers (svix-id, svix-timestamp, svix-signature). Rotate the secret in Webhooks to see it, add verification, add request events by hand if you used them, then set status to enabled.

6. 6

   Re-record SMS consent

   Brevo's SMS opt-outs do not import. Before any marketing text, record each contact's consent where they gave it (POST /api/v1/contacts/{id}/sms-consent) or ask them to confirm with POST /api/v1/contacts/{id}/sms-opt-in-request. A phone number on a contact is not consent.

7. 7

   Send tests

   Send each template with POST /api/v1/email/templates/{id}/test-send, and fire POST /api/v1/webhooks/{id}/test at each endpoint.

8. 8

   Move traffic in stages

   Move transactional mail first, watching email.bounced and email.complained, then campaigns. Brevo stays authenticated, so rolling back is a config change.

9. 9

   Cancel Brevo last

   Finish the checks below, then downgrade or close the account.

Before you cancel Brevo

• Export contacts and segments as files, including SMS numbers and SMS opt-outs, which do not import.
• Export the campaign reports and email logs you want to keep; none of them move.
• Pull the transactional blocked contacts one last time and add new ones here.
• Delete Brevo's DKIM and verification records once no mail goes through Brevo. Keep _dmarc and Unitpost's records.
• Turn the IP allowlist back on if you switched it off for the migration, then revoke the API key you used.

Facts about Brevo checked 2026-11-02. Providers change their APIs and plans; check their docs before you rely on a detail.