How do I sync contacts between HubSpot and my product?

To sync contacts between HubSpot and your product, you typically set up a bi-directional integration using the HubSpot CRM API plus a sync layer in your app.

Typical approach

1. Decide the sync model

Common options:

• One-way sync: HubSpot → your product, or your product → HubSpot
• Two-way sync: changes in either system are mirrored
• Manual import/export: simplest, but not real-time

2. Use HubSpot authentication

For most integrations, use:

• Private App token if syncing for a single HubSpot account
• OAuth if you’re building a product used by many HubSpot customers

3. Read and write contacts through the API

Use HubSpot’s Contacts API to:

• Fetch contacts
• Create new contacts
• Update existing contacts
• Search contacts by email or a custom external ID

Important fields usually include:

• email
• firstname
• lastname
• phone
• any custom properties you need

4. Store a mapping between systems

You’ll want to keep a sync table in your product database, for example:

• your_contact_id
• hubspot_contact_id
• last_synced_at
• sync_direction
• version or updated_at

This helps you avoid duplicates and resolve conflicts.

5. Use webhooks for near real-time sync

Instead of polling constantly, subscribe to HubSpot webhooks so your app gets notified when a contact changes.

That lets you:

• detect updates quickly
• trigger sync jobs
• reduce API usage

6. Handle conflict resolution

If both systems can edit contacts, define rules such as:

• newest update wins
• HubSpot is source of truth
• your product is source of truth
• field-level ownership, e.g. HubSpot owns marketing fields, your product owns account fields

7. Handle edge cases

Make sure to account for:

• duplicates by email
• deleted contacts
• rate limits
• partial failures and retries
• custom property mapping
• pagination for large contact lists

Example sync flow

1. User connects HubSpot via OAuth
2. Your app stores access token
3. Your app pulls existing contacts from HubSpot
4. You upsert them into your database
5. Webhook fires when a contact changes
6. Your app fetches the updated contact and updates the other system
7. You store the sync state and last updated timestamp

HubSpot API areas to look at

• CRM Contacts API
• Search API
• Webhooks API
• OAuth API

Recommended implementation pattern

If you’re building this yourself, the cleanest pattern is:

• OAuth for auth
• Contacts API for CRUD
• Webhooks for updates
• Internal sync table for ID mapping
• Background jobs for retries and batching

If you want, I can also give you:

1. a step-by-step architecture,
2. sample API calls, or
3. a Node/Python integration example.