If you run marketing from Brevo but your customer data lives in ERPNext, you end up maintaining two disconnected address books. Sales updates a Contact or Customer in ERPNext, someone re-keys it into a Brevo list, and the segments drift within days. ERPNext core has an Email Group and Newsletter feature, but it has no concept of Brevo lists, no SMS channel, and no way to see who opened or clicked a Brevo campaign back on the customer record. Marketing operates blind to what the CRM knows, and the CRM never learns what marketing did. This connector closes that loop.

We build a proper Frappe app — its own module, DocTypes, and hooks.py wiring — that treats Brevo as a first-class integration inside ERPNext. A single Brevo Settings DocType holds the API key (stored as a Frappe Password field, never in plain text) and default sender identity. Contact and list sync runs through the Brevo REST API v3: on_update doc events on Contact/Customer/Lead push changes to Brevo contacts and map ERPNext fields to Brevo attributes, while a scheduler event reconciles Brevo lists into a Brevo List DocType so marketers pick real, live lists from a Link field. Campaign and transactional sends go through whitelisted methods (@frappe.whitelist()) invoked from client scripts or workflow hooks, so you can trigger an email or SMS from a button, a workflow transition, or a server script — not just from a separate marketing tool.

The engagement back-sync is the piece ERPNext can't do natively. We expose a signed webhook endpoint (a whitelisted, allow_guest method with HMAC verification) that receives Brevo delivery, open, click, bounce, and unsubscribe events and writes them to a Brevo Engagement Log child/linked DocType against the matching Contact. That turns raw campaign activity into queryable ERPNext data — report on click-through by customer segment, or fire an automation when a lead clicks a specific campaign. All API traffic runs through Frappe's background queue (frappe.enqueue) with retry and rate-limit handling so a Brevo hiccup never blocks a save, and every call is written to an integration log for auditability. Role-based permissions and role profiles keep the API key and send buttons restricted to marketing roles.

Because this is build-to-order, nothing ships until we agree on scope. You request a quotation, we run a short scoping call to confirm which DocTypes sync, your field-to-attribute mapping, which channels (email, SMS, transactional) you need, and your Frappe/ERPNext version (v15 or v16). We then build against a staging copy of your site, run UAT with you, and install to production with a rollback plan. Typical delivery is one working week from confirmed scope, and you receive the full app source and git repository so you are never locked in.