Your business probably runs on several systems: a website, a CRM, an accounting package, a payment provider, maybe a booking tool or warehouse system. When they don't talk to each other, people copy data between them by hand, slowly and with mistakes. API integrations connect those systems so information flows automatically. Here's what that means, without the jargon.
APIs in plain English
An API (application programming interface) is a way for one system to ask another for information, or to do something, using agreed rules. A helpful analogy is a restaurant: you (one system) give your order to the waiter (the API), who takes it to the kitchen (the other system) and brings back what you asked for.
APIs vs webhooks
| API request | Webhook | |
|---|---|---|
| Who starts it | Your system asks | The other system tells you |
| When | Whenever you need data | Instantly when an event happens |
| Example | "Give me today's orders" | "A new order was just placed" |
| Good for | Fetching or updating data on demand | Real-time reactions to events |
Most integrations use both.
Common business integrations
| Connection | What it automates |
|---|---|
| Website form → CRM | New enquiries appear in the CRM instantly |
| Online store → accounting | Sales, fees and refunds post automatically |
| Store → warehouse or 3PL | Orders are sent for fulfilment, tracking returned |
| Payment provider → app | Subscriptions activate or pause based on payment status |
| Booking system → calendar and email | Appointments sync and reminders send automatically |
| CRM → email marketing | Contacts move into the right email sequences |
Three ways to integrate
| Option | How it works | Best for | Watch out for |
|---|---|---|---|
| Native integration | Built-in connection between two tools | Common pairings, like Shopify and Xero | Limited flexibility |
| No-code tools (Zapier, Make, n8n) | Visual workflows connecting apps | Simple, low to medium volume | Costs and complexity grow with volume |
| Custom integration | Developers write code using the APIs | Complex logic, high volume, critical processes | Higher upfront cost, needs maintenance |
Start with native integrations, use no-code tools for simple gaps, and build custom integrations where reliability and complexity demand it. Our guide to workflow automations has more examples.
Planning an integration
- Map the process: what triggers it, what data moves, and where?
- Decide the source of truth: which system owns each type of data?
- Check the APIs: what each system allows, and any limits or costs
- Define error handling: what happens if a system is down or data is invalid?
- Consider security: who and what has access to which data?
- Plan monitoring: how will you know if it stops working?
Risks and how to manage them
| Risk | Mitigation |
|---|---|
| Silent failures | Alerts and logs when syncs fail |
| Duplicate records | Unique identifiers and deduplication rules |
| API changes by a provider | Monitoring, maintenance and versioned APIs |
| Rate limits | Queues and retries |
| Security exposure | Least-privilege access, secure credential storage |
| Data protection | Only share the personal data needed, with appropriate agreements |
What affects cost
- Number of systems and data types involved
- Quality of the systems' APIs and documentation
- Complexity of the rules and transformations
- Volume of data and need for real-time updates
- Error handling, monitoring and ongoing maintenance
Questions to ask a developer
- Which system will be the source of truth for each data type?
- How will failures be detected and handled?
- What happens if one system's API changes?
- How will the integration be monitored and maintained?
- Can we see logs of what's been synced?
Example: connecting a website form to a CRM and team chat
| Step | What happens | Detail |
|---|---|---|
| 1 | A visitor submits the enquiry form | The website validates the fields |
| 2 | The website sends the data to the CRM's API | Creates or updates a contact and a deal |
| 3 | The CRM fires a webhook | "New deal created" |
| 4 | The team chat receives a notification | "New enquiry from Sarah at Acme: website redesign" |
| 5 | An email confirmation is sent to the visitor | Sets expectations for a reply |
| 6 | Errors are logged and alerted | If the CRM is unavailable, the enquiry is queued and retried |
The result: no enquiries lost in an inbox, faster responses and a full record in the CRM.
Glossary of integration terms
| Term | Meaning |
|---|---|
| API | A way for systems to request data or actions from each other |
| Endpoint | A specific address within an API, such as "create contact" |
| Webhook | An automatic notification sent when something happens |
| Authentication | How systems prove they're allowed to connect |
| Rate limit | A cap on how many requests can be made in a period |
| Payload | The data sent in a request or notification |
| Sync | Keeping data consistent between systems |
| Middleware | Software that sits between systems to connect them |
How we help
Our API design and integrations service connects your systems reliably, with documentation, error handling and monitoring. For CRM-specific work, see CRM integration and AI enrichment, and for online stores, inventory and ERP sync. If you're deciding whether to build or buy, read custom software vs off-the-shelf tools.
The short version
APIs let systems request data and actions from each other; webhooks let them announce events instantly. Integrate with native connections first, no-code tools for simple gaps and custom code for complex or critical processes. Plan the source of truth, error handling, security and monitoring before building.
