Sync HubSpot contacts to Constant Contact with an audit log

Build me a code workflow that syncs HubSpot contacts into Constant Contact whenever a contact is created or updated in HubSpot, and writes an audit row to Google Sheets after each sync.

Trigger: a HubSpot webhook subscribed to contact create and contact update events. The workflow should fire once per webhook event.

Step 1. Read these fields from the HubSpot webhook payload (fetching the contact from HubSpot if the webhook only carries the contact ID): email, first name, last name, phone, lifecycle stage, and a configurable list of additional HubSpot properties that the user can extend.

Step 2. Map the HubSpot lifecycle stage to a Constant Contact list using a configurable lookup table on the workflow. Example default mapping: marketingqualifiedlead maps to an MQL Nurture list, salesqualifiedlead maps to an SQL list, customer maps to a Customers list, and any unmapped stage falls back to a configurable default list. Both the lifecycle stage keys and the Constant Contact list IDs must be editable as workflow configuration.

Step 3. Call Constant Contact's Create or Update Contact (Sign-up Form) operation with the contact's email, first name, last name, phone, the target Constant Contact list ID from the mapping, and any mapped HubSpot properties copied into Constant Contact custom fields or tags according to a configurable property mapping. The Sign-up Form operation handles upsert by email, so the same contact is created on first sync and updated on later syncs.

Step 4. After the Constant Contact write succeeds, append a row to a configured Google Sheet using the Append Values operation. The row should contain: ISO timestamp, HubSpot contact ID, email, lifecycle stage, target Constant Contact list ID (and human-readable list name if available), and the resulting Constant Contact contact ID. Use the spreadsheet ID and sheet tab as workflow configuration.

Configuration the workflow should expose: the HubSpot lifecycle-stage-to-Constant-Contact-list mapping (with a default/fallback list), the HubSpot property to Constant Contact custom field/tag mapping, the Google Sheets spreadsheet ID and tab name for the audit log, and the list of additional HubSpot properties to pull from the contact record.

Keep this strictly deterministic with no LLM reasoning steps. It is a fixed pipeline: webhook in, mapping, Constant Contact upsert, audit row out.

Additional information

What does this prompt do?

Watches HubSpot for new and updated contacts in real time, so changes flow into your email tool without manual exports.
Routes each contact to the right Constant Contact list based on their HubSpot lifecycle stage (for example, MQLs into your nurture list and customers into your customer list).
Copies over the contact details you care about, including first name, last name, phone, and any HubSpot properties you want mapped into Constant Contact custom fields or tags.
Writes a clean row to a Google Sheet for every sync so marketing ops can spot failures, reconcile lists, and audit who landed where.

What do I need to use this?

A HubSpot account where you can set up webhooks for contact create and update events.
A Constant Contact account with the lists you want to sync into already created.
A Google account with a spreadsheet ready to use as the sync audit log.
Your lifecycle-stage-to-list mapping decided ahead of time (for example, which Constant Contact list each HubSpot lifecycle stage should land in).

How can I customize it?

Adjust the lifecycle-stage-to-list mapping so each HubSpot stage routes to the Constant Contact list you want, and add a fallback list for contacts that do not match any stage.
Pick which HubSpot contact properties get copied across, and whether each one becomes a Constant Contact custom field or a tag.
Choose which Google Sheet and tab the audit log writes to, and add extra columns if you want to track things like source, owner, or campaign.

Frequently asked questions

Why not just use the native HubSpot to Constant Contact connector?

The native connector cannot route contacts to specific Constant Contact lists based on lifecycle stage. This workflow gives you that control, plus a per-sync audit trail you can reconcile later.

Will this work on HubSpot Free?

Yes. The workflow uses HubSpot webhooks and the standard contacts API, both available on Free and paid tiers. You only need permission to manage webhooks and read contacts.

What happens if the same contact is updated in HubSpot multiple times?

Each update fires the webhook and runs the workflow. Constant Contact upserts by email, so the contact is created the first time and updated on every subsequent change. Each run also appends its own row to the audit log.

Can I add or change lifecycle-stage-to-list mappings later?

Yes. The mapping is a configuration you can edit on the workflow at any time. New stages, new lists, and fallback rules are all easy to tweak without rebuilding the workflow.

What if the Constant Contact write fails?

The workflow will surface the failure so you can retry. You can also extend the audit log to capture failed attempts, which marketing ops can review alongside successful syncs.