HubSpot's API on the Free CRM: What You Can Actually Build
Does the free HubSpot plan let you build an integration over the API? What you can read and write in the free CRM, where the limits are, and when a custom interface makes sense.
HubSpot's API on the Free CRM: What You Can Actually Build
One question lands on my desk again and again, usually right at the start of a project: "We're on free HubSpot. Can we even build an integration with that, or do we have to buy a paid plan first?"
Short answer: yes, the API is fully usable on the free CRM. You can read and write contacts, companies and deals over the interface without paying HubSpot a cent. There are a few real limits, but they sit somewhere other than most people expect.
Here's what actually works in the free tier over the API, where it stops, and at what point the jump to a custom interface or a higher plan starts to pay off.
How API access works at HubSpot today
Anyone who integrated with HubSpot a few years ago remembers the old API keys: one key per account with access to everything. HubSpot retired those. Today access runs through two routes.
For your own internal connections, you build a private app. You do this right in your HubSpot account settings: create the app, define which areas it may read and write (the so-called scopes), and you get an access token. You talk to the API with that token. This works the same way on the free CRM as it does on an Enterprise account.
The second route is OAuth apps. You need those when you build an application that signs in to other people's HubSpot accounts, such as a product for the HubSpot marketplace. For a normal connection to your own CRM, that's overkill. A private app is enough.
Worth keeping in mind: a private app is not rocket science, but it needs some care. The token is effectively a master key to the areas you granted it. It belongs in secure storage, not in your frontend and not in a public repository.
What you can connect in the free CRM
The HubSpot CRM is built around a handful of standard objects, and they are all reachable over the CRM API, free included:
- Read, create and update contacts and companies
- Manage deals and tickets
- Attach activities like notes, tasks, emails, calls and meetings to records
- Set associations between objects, for example linking a contact to a company and a deal
- Read and fill properties, including custom fields you created in the CRM
That covers the bulk of what integrations get built for in practice. A typical case from my projects: a form on an external platform creates a contact in HubSpot over the API, links it to the right company and opens a deal in the correct pipeline. No paid plan needed for any of that.
Reading works cleanly too. You can use the search endpoints to filter for specific records, page through larger volumes and pull exactly the properties you need. For a nightly sync with another system, that's plenty.
Where the free tier really stops
The limits don't run along the line of "API yes or no". They run along three other lines.
Custom objects. If your business needs object types HubSpot doesn't know out of the box – say "vehicles", "contracts" or "machines" as their own object type with their own fields and associations – you need an Enterprise plan for that. On the free CRM you model those cases through the existing objects and custom properties. That often goes surprisingly far, but eventually it hits a natural ceiling.
Real-time notifications. If your integration should react the moment something changes in HubSpot, you want webhooks instead of regular polling. Those run through an app configuration and aren't as freely available in the standard CRM as plain reading and writing. In many projects I solve this pragmatically on the free tier with a scheduled sync every few minutes. For most use cases that's fast enough.
Certain hub-specific APIs. Features tied to Marketing Hub, Sales Hub or Operations Hub at higher tiers are only reachable over the API if you actually have that plan. Programmatic data quality through Operations Hub is one example. The plain CRM stays untouched by this.
Rate limits: the thing to learn about early
HubSpot caps how many API calls you may make in a given time window. That's the factor that really matters with larger data volumes, not the plan itself.
For private apps in the free and starter range, the limit sits at roughly 100 requests per 10 seconds and around 250,000 requests per day according to the HubSpot documentation (as of early 2026; HubSpot adjusts these figures, so check the official limits page if in doubt). Higher plans mainly raise the daily ceiling.
What does that mean in practice? As long as you sync individual records or work spread across the day, you won't notice these limits at all. It gets tight during large initial loads or frequent full syncs. If you want to read in 100,000 contacts in one go, you have to build the run so it respects the limits: work in batches, use the batch endpoints that handle multiple records per call, and on a limit hit wait cleanly instead of firing on blindly.
This is exactly where it's decided whether an integration runs stably day to day or keeps stalling. The HubSpot plan isn't the problem. How the interface handles the limits is.
When the free CRM is enough and when it isn't
From experience: for a clean connection between HubSpot and one or two other systems, the free CRM is enough in the vast majority of cases. Contacts in, deals updated, data synced between tools, a form connected. I build all of that on free accounts regularly.
A higher plan comes into play when one of these applies: you need your own object types beyond contact, company, deal and ticket. Your processes depend on features of a specific hub. Or your data volume regularly blows past the free tier's daily limits.
And there's a fourth case that has nothing to do with the HubSpot plan: as soon as the logic between systems gets more involved, a custom interface in between pays off. A small piece of middleware that merges data from several sources, converts fields, handles edge cases and keeps the rate limits in check. The HubSpot API gives you the building blocks. How robust the whole thing runs in the end depends on what happens between the APIs.
I build interfaces like that at Pipewave: from the simple form connection to middleware that links HubSpot with an ERP, accounting or a custom application. What that looks like in a real project I show in the n8n-HubSpot workflows case study.
If you're weighing whether your HubSpot plan covers your planned connection, take a look at what I do around CRM integration, or write to me directly through the contact form. I'll tell you honestly whether the free CRM carries your case or where you hit a real wall.
Written by Joshua Kresse. At Pipewave I build HubSpot integrations and custom interfaces for B2B companies.