HubSpot is a CRM platform; ContactAPI is a contacts API. The comparison is really whether you need a CRM or just need to store contacts.
At a glance
- Scope. HubSpot covers CRM, marketing, sales, and service; ContactAPI stores and manages contacts.
- Data model. HubSpot has objects, properties, and associations; ContactAPI has an email plus any JSON fields.
- Setup. HubSpot needs an account, app, and OAuth; ContactAPI needs a key and a POST.
- Cost. HubSpot uses tiered CRM pricing; ContactAPI is open-source and self-hostable.
Choose HubSpot when
A team needs pipelines, email sequences, and reporting, plus a place where non-developers work leads through stages.
Choose ContactAPI when
You want the contacts table without the CRM around it: a simple endpoint your code calls, and data you can query yourself. You can always export to a CRM later.
Where ContactAPI fits
ContactAPI is an open-source REST API for saving and managing contacts. You POST an email plus any JSON fields, get simple CRUD back, and can reach the same data from an AI client over its MCP server. No CRM, no pipeline stages, no lock-in.