A wholesale distributor runs its orders, credit limits and account terms in an ERP. Its sales team works in the CRM. The ERP vendor offers a connector, but it only syncs finished invoices, once a night. So a rep calls a customer about a new product line without knowing the customer placed a large order that morning, or that the account was put on credit hold yesterday. The rep looks uninformed. The customer notices.
The connector was built for accounting, and for accounting it was fine. Sales needed different data, and needed it sooner. That kind of mismatch is the usual reason a business ends up looking at a direct API integration.
What is an API integration, in plain terms?
An API integration is a connection where one system asks another for data, or sends data to it, using the rules that system publishes for doing so. Most modern platforms, including CRMs like HubSpot, Zoho and Salesforce, and marketing platforms like Klaviyo, provide a REST API: a set of web addresses that each represent something in the system, such as contacts, companies, orders or events, which you can read from or write to.
You don’t need to understand the technical detail to make good decisions about one. What matters is knowing which information should move, in which direction, how quickly, and what should happen as a result. Those are business decisions, and they’re where most of our time goes.
When are native integrations not enough?
Native integrations aren’t enough when they don’t sync the objects, fields or events your process depends on, or when they sync them in a way that conflicts with your rules. If a native integration does what you need, use it. It’s maintained by the vendors and usually costs nothing extra.
The gaps we see most often:
Sometimes a workflow tool closes the gap. Make and n8n can call APIs directly, and for moderate volumes that’s often the most maintainable option. A dedicated integration makes more sense when volumes are high, timing is critical, or the logic is complex enough that a visual builder becomes hard to follow.
How we design an API integration
Decide what each system owns
Before mapping a single field, we agree which system is the source of truth for each piece of information. The ERP owns credit status. The CRM owns the account owner and lifecycle stage. If two systems can both edit the same field, we decide which one wins and when. Most integration problems we’re asked to fix trace back to this step being skipped.
Set up authentication properly
Every API needs to know who is calling it. Depending on the platform, that means an API key, a private app token or an OAuth connection. We connect through a dedicated integration user or app rather than someone’s personal login, grant only the permissions the integration needs, and store credentials securely, so the integration doesn’t break when an employee leaves and isn’t over-privileged while it runs.
Map the data, field by field
Mapping means deciding where each piece of data lands and how it changes on the way. Dropdown values must match the CRM’s options exactly. Dates and currencies must be in the format the CRM expects. Most importantly, we decide how records are matched: by email, by a customer number from the other system, or by a stored external ID. Matching on a name or a free-text field is how duplicates are born.
Choose how events are synced
Some data is best pulled on a schedule, such as a nightly refresh of account balances. Other changes should be pushed the moment they happen, such as an order placed or a subscription canceled. Many systems can send these instantly using webhooks, which avoids repeatedly asking “anything new?” We choose per event, based on how quickly the business needs to act on it.
Validate before writing
The integration checks incoming data before it touches the CRM. Is the email address valid? Is the required field present? Is this a test record? Records that fail are held for review, not silently dropped and not written half-complete.
Plan for errors from day one
APIs have rate limits, systems have outages, and tokens expire. A good integration retries temporary failures, logs every attempt, alerts a named person or shared channel when something keeps failing, and can replay missed records once the problem is fixed. Without this, the first sign of trouble is usually a salesperson asking why a customer is missing.
Is your connector leaving important data behind?
We'll look at the systems involved, what the native integration does and doesn't sync, and recommend the simplest approach that will hold up.
What happens after launch
An API integration isn’t finished when it goes live. Platforms release new API versions and retire old ones, sometimes on a published schedule. HubSpot and Klaviyo, for example, both version their APIs and deprecate older endpoints over time. Fields get added to the CRM. Someone renames a dropdown option and the mapping quietly stops matching.
So we document every integration we build: what it moves, what rules it applies, which credentials it uses, where it logs, and who to contact when it fails. We also include a short test plan, so changes on either side can be checked before they reach live data. If you’d like us to keep an eye on things after launch, that fits naturally into CRM optimization.
Where API work fits in a CRM project
We don’t build integrations in isolation. A direct API connection is only as good as the data model it writes into, so the work usually sits inside a broader CRM integration or CRM implementation project. When we’re working alongside your developers, we write the requirements and the field mapping, review the logic, and test the result against real scenarios. Our requirements documentation service exists for exactly that situation.
For smaller connections, we build them ourselves with a workflow tool or a lightweight service, whichever will be easier for your team to own afterward.
Should we poll the API or use webhooks?
Usually some of each. Polling means asking the other system on a schedule whether anything has changed, which suits slow-moving data like account balances, or systems that don’t offer webhooks. A webhook is the other system telling you the moment something happens, which suits events that need quick action. A common pattern is a webhook to learn that an order was placed, then an API call to fetch the full order and update the CRM.
Can’t Zapier or Make do this instead?
Often, yes. If the volume is moderate and the logic fits comfortably in a visual workflow, a workflow tool is usually cheaper to build and easier to maintain. A dedicated integration becomes the better choice when volumes are high, timing is critical, or the rules are complicated enough that the workflow becomes hard for anyone to follow.
Do we need our own developers?
Not necessarily. We handle the planning, mapping and testing in every case, and build smaller integrations directly. For large or business-critical integrations, involving your own developers or a development partner is often sensible, because they’ll host and maintain the code long term.
Who owns the integration once it’s built?
You do. Credentials, code and documentation sit in your accounts, not ours. We’d rather hand over something your team understands than create a dependency.
How is our data protected during an integration?
We use dedicated, limited-permission access, keep credentials out of shared documents and messages, and move only the data the process needs. Our security and data processing pages explain how we handle client data.